William Wynne

Ask The Authority! January-June 2003 Daily Question & Answers

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then by all means e-mail William at WilliamTCA@aol.com. Thank you.

Subj: RANS S-6 COYOTE

Date: 6/30/03 I've been spending much time on your Web site and am very interested in your Corvair engine. Do you think that it would be compatible with a Rans S-6S Coyote? The company recommends/sells any Rotax between the 582 to the 912S for the plane. The Rotax is about 40 lighter than the Corvair and that is without the electric starter. Any thoughts on this issue would be greatly appreciated. Thanks.

Steve Hart, Bremerton, Wash., harts@psns.navy.mil

Reply from WW:

I have not studied the Rans designs closely as they rarely fly with alternative engines. A good starting point with an airframe designer is to ask him whether or not the particular design could be flown with an O-200. Almost all airplane designers are familiar with the O-200's size, weight and power characteristics, which are closely matched to the Corvair's. In my experience, many airplane designers, while masters of their art, are not well versed in alternative engines. Although we think of the Corvair as being very popular, many airframe designers do not have direct experience with them and certainly many of their opinions are based on old wives' tales about the engine. Phrasing the question about an O-200 will generally yield useful technical data without addressing an airframe designer's limited Corvair exposure. About once a week we get a letter from an airplane builder who says his airframe designer states that Corvair motors are either too heavy, don't make enough power, etc. In many cases, these designers could not answer fundamental questions such as how many cubic inches is a Corvair, how much does it weigh, or basically, have you ever seen one turn a propeller before. The majority of respected designers, when asked a question about a subject they're not well versed in, will simply say "I don't know much about it." Sometimes we deal with the reverse.

Subj: Corvair-powered Junior Ace question

Date: 6/29/03 I'm deciding whether to build a Piet or a Junior Ace in my garage. If I were to use a Corvair engine in a Junior Ace, including an electric starter, could I safely keep the weight under the LSA limit of 1232 pounds?

Mark Hodgson, mhodgson@bu.edu

Reply from WW:

Either airplane, Piet or Junior Ace, can be built with a full electric start Corvair and still retain an excellent useful load. There are many examples of Corvair-powered Pietenpols. If you'd like an example of a Corvair-powered Junior Ace, check out Jake Jaks' Web site, http://home.att.net/~jrjaks/index.html. Jake was the first graduate of Corvair College. Either of these aircraft are excellent performers on a Corvair motor, far exceeding their original performance on engines like 65 and 75hp Continentals which are now unaffordable, and never offered such conveniences as full electric starting.

Subj: Corvair car carbs

Date: 6/28/03 I just happened to take a look at the Pietenpol and ended looking at your Web site on converting the Corvair engine for aircraft use. I have only one question: Can you use the original carb (the one used in the car) for aircraft use? Thanks.

Dean, deanvoisine@yahoo.com

Reply from WW:

The Corvair cars have 2 or 4 downdraft carbs (depending on the model) bolted directly to the head. They are 4" tall and would be impossible to streamline into a cowl.

Subj: Carb, safety shaft, prop

Date: 6/27/03 I have started conversion of a Corvair engine for a Zodiac CH601 HD project using your Manual and info from your Q & A on your Web site. I am hoping for about 110hp using the OT-10 cam, forged pistions .060 overbore (because .010 not available) and other mods according to your Manual. I would like to know whether a Stromberg NAS-3 with 32mm venturi is large enough to produce 110 hp. I have contacted a local machinist to make a safety shaft. He would like to know whether the two grooves are necessary (one is 1" from one end, the other is 2" from other end). Can these grooves be eliminated? Would a 2-blade, 68" Warp Drive prop, #N6515 be suitable for my project?

Bob Duns, Zodiac CH601 HD, Manual #5053, rduns@sasktel.net

Reply from WW:

Getting a full 110hp out of a standard displacement Corvair involves winding the motor up to approximately 3200rpm. This will not harm the motor at all. The two considerations you mention are prop diameter and carb venturi. In the interest of more power, I would suggest the larger 1 3/8" Stromberg venturi. The smaller one is effectively limited to 85 or 90hp on a Corvair. To wind the motor to 3200rpm, I believe a 66" two-blade Warp Drive would be a better bet than a 68". Keep in mind that the Warp Drive is solid carbon fiber and can be trimmed to any desired diameter. Thus, a prop ordered as a 68" could easily be trimmed with a hacksaw. The two grooves on the safety shaft are to provide a clean end to the threading. This way, the shaft butts squarely on the end of the crank. It also works to reduce the stress rising tendency of the end of a thread. Over the years, we've had absolutely zero problems here, but the groove style in the drawing is standard engineering practice.

Subj: Corvair for Zenith CH 701?

Date: 6/26/03 I have been looking at the Zenith 701 design. While it is aesthetically challenged, it has its advantages. I noticed it has been built with many different engine installations. Do you know if one has been built with a Corvair conversion? What are your thoughts on this application? Thanks in advance,

Karl F. Counts, Karl@CountsFamily.com

Reply from WW:

I recently exchanged e-mail with Sebastien Heinz, in which he reiterated his family's position that the best engines for the 701 are the lightest ones, although their Web site and advertising shows engines that are heavier than the Corvair, like the O-200 and EA-81s with reductions. If the airframe will fly with the weight of these engines, the airplane will certainly fly with a Corvair. Sebastian just feels that it's better off with the lightest motor you can get.

Subj: Ignition

Date: 6/25/03 Using your dual points distributor, one must need to employ an "automatic coil selector," since both sets of points use the same plugs. If one coil shorts (the old shorting tach question) does the coil selector default to that set of points?

John Sandt, Avid or Kitfox, Calif., josandt@netzero.com

Reply from WW:

The coil selector has no moving parts. It functions as two diodes. What is selecting which ignition system you're on is a panel mounted switch providing 12volt power to the positive side of either your A or B coil. Thus, you have to manually switch it to the other side. Although you can run both at the same time, it is not recommended by the manufacturer. On all installations, I recommend this switch be put in a position where you can change it without removing your hand from the stick or the throttle.

Subj: Corvair in Brazil

Date: 6/24/03 Thanx for your response. I saw Mr Tadeu's message at your site and contacted him, congratulating him on finding a Corvair (alive!) here in Brazil, which is almost impossible. Unfortunately he found only one! Time is not really a concern, as I didn't really start my KR2S yet. FYI it's quite possible that I will show-up at Oshkosh this year and them we could talk directly. By the way, I was at Sun 'n Fun and watched your forum. Best Regards,

Oswaldo, KR2S, Rio de Janeiro, Brazil, oswaldo10@globo.com

Reply from WW:

If an engine does not turn up by the time you need one, I certainly can arrange an export if it's required. I have shipped engines to England and Australia. I have great respect for anybody who would build an airplane under what have to be more challenging circumstances than anyone would face within the United States. Most U.S. guys don't stop to realize how lucky we are. Thank you for coming to one of my forums at Sun 'N Fun. Although there's always a crowd around, I am very much a people person, and under these circumstances, especially if we haven't had the chance to meet before, I encourage anyone to introduce themselves and spend some time with us. I attend these events from coast to coast specifically to meet people in person. The forum is just a way of starting the discussion. I'm looking forward to meeting you and many other friends, new and old, at Oshkosh this year.

Subj: Avid Mark IV and Corvair

Date: 6/23/03 I have an Avid Mark IV..is the Corvair well suited for this aircraft? I now have a Rotax 582 and am considering a VW... Corvair...or a Subaru... Thanks,

Mike Allman, Avid Mark IV, Knoxville, Tenn., MCALLMAN@aol.com

Reply from WW:

We have a couple guys working on Corvair installations on their own Avids. On the Mark IV, it's important to have the heavy duty model for any 4-stroke installation. The Corvair motor falls between the VW and the Subaru for installed weight. A typical Corvair is approximately 35lbs. heavier installed than a Type I VW. With a conversion to VW cylinders, the weight difference on the Corvair would shrink to 26-28 lbs. And of course, the Corvair engine would have 900cc+ (about 55cid) more displacement. The Subaru EA-81, with its smallish 1800cc displacement, has to be worked very hard through a belt reduction to be in the same power league as the standard Corvair engine. In recent years, builders have removed several EA-81 installations and replaced them in the same aircraft with Corvair power plants. In all instances, the Corvair was substantially lighter. Although the EA-81's base motor may be lighter than the Corvair, its proponents frequently tout the engine's weight without the hoses, water, radiator, thermostats, etc., that are required to go flying. I don't know why this practice is tolerated, but it's silly. In a typical case, a standard Corvair motor with iron cylinders in a direct drive format will be 35-40 lbs. lighter than an EA-81 with its required PSRU ready to fly.

Subj: Vari-Eze

Date: 6/22/03 Can you give me a source for information and your opinion about using the Corvair engine to power a Vari-Eze? Thank you.

Del Ralston, N770DY, drals1234@adelphia.net

Reply from WW:

We have several people working on VariEz installations of Corvair motors, but I'm not aware of anyone currently flying this combination. I did a design study and built a motor mount for my friend Arnold Holmes' VariEz. He has since sold the project to a group of builders in a Minnesota EAA chapter. Arnold and his father are planning on moving to a grass strip, which would not be favorable for a VariEz. I intend to stay in touch with the new owners and will keep you posted on the installation.

Subj: Corvair engines (of course!)

Date: 6/21/03 I am in receipt of your wonderful Manual, I've read it through at least three times and I want to thank you for its simplicity and real educational value. Thank you.

I've started to look for an engine and I've found that people who have the engines we want DO NOT ADVERTISE THEM! They'll advertise a turbo or a 140 HP, but not a 110 HP. If you contact someone who is selling a 140 HP and ask, he'll probably have just what we need, but he didn't think it had much value, so he didn't include it in the ad. There's even one advertisment on e-bay right now that is for two 140 HP engines; if you buy the two 140s, he'll throw in a 110 HP engine for free! Ironic, isn't it! The real stickler in all this is the cost of shipping an engine. I can't seem to find one local enough to just drive there and pick it up. Does Clark's sell used engines? I'm in Massachusetts.

You should have my order for the Quarterly Newsletter by now. I am looking forward to having a rewarding time building my Corvair engine and deciding on the correct aircraft to build to complement it. Thanks again,

Gerald N. Scampoli, Mass., GScampoli@HomeMarketFoods.com

Reply from WW:

That is a very keen observation you've made on 110s. A 180 turbo or 140hp Corvair motor is worth five to 10 times what a 110 or 95 is. So, your observation may be even more common than you suspect. Keep running down leads in your own area. Massachusetts has a reputation for being rich with Corvairs. Clark's does sell whole engines when they have them, and they have a huge selection of used parts also.

Subj: Corvair Cranks

Date: 6/20/03 I'm wondering what your process is for adressing crankshafts. Do you automatically do the 10/10, do you expect it to be done before you get it, or do you handle it on a case by case basis subject to inspection? Are you doing the regrinds, or sending that out?

Another question is: Is there an advantage to regrinding an in-spec crank just to clean it up, or is there a downside to the regrind which makes avoiding it desirable?

What exactly are the options here? I suppose I could have it reground locally, and then send it your way for safety shaft modifications, or perhaps the other way around would work too.

My thought is, if you are outsourcing the machine-shop work, there is probably not a lot of use in sending you the raw crank, causing you to have to do the legwork to send it somewhere else. Conversely, I want your hands involved in the safety shaft because I want somebody who knows how it's supposed to look when it's done. Thoughts?

Clay "Hoppy" Hopperdietzel, Vision, Tomball, Texas, hoppy@houston.rr.com

Reply from WW:

The grinding and threading are handled for me by two craftsmen who have done virtually all of them since 1997. (I never publicly identify who these guys are because they are small businessmen with families and I would never jeapordize their situations in the litigation prone world of aviation. In all of my years in business, I have never been involved in a lawsuit, but I would not have these fine craftsmen be made nervous by unnecessary publicity.) These guys are very, very good, but the jobs they tackle on the Corvair stuff would not challenge any competent guy in your area. To address the safety shaft issue, I suggest you purchase one from me ($66 for U.S. orders, $81 for international orders, by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802 or by credit card at the FlyCorvair.com Online Catalog) so the machinist can have it in hand when he threads the crank. If your crank is within factory limits, then it is perfectly acceptable to fly it. Most machine shop guys agree that engines operated continuously at high output benefit from looser tolerances on the bearings.

Subj: Possible engine for Fybaby Project?

Date: 6/19/03 I'm looking into getting a partially-done Flybaby project. I'm a newbie, and have never done any home-built projects before. The plane comes with a Continental O-290G, which I'm told is too heavy for the plane. A friend gave me your Web site, and I'm very intrigued. Would a Corvair engine be as light or lighter than a Continental O-200/ 85 Hp? The cheaper aspect of the engine certainly is appealing - especially to my limited pocketbook. The 6 cylinders seemingly would make it a smooth-running engine. Has anyone else used it for a Flybaby before? Any info or advice would be greatly appreciated. Thank you,

Jeff Patnaude, Snellville, Georgia, EAA 690, patnaude@comcast.net

Reply from WW:

Good to hear from you. As you probably know, the Flybaby was designed in the early 1960s by Peter Bowers, one of the aviation greats of all time. It is a sad note that Peter Bowers passed last month. Aviation as we know it is far richer because of Peter Bowers' writing and photography. His aviation photography collection and his knowledge of light aircraft are unmatched. We can only hope that his collected works will be made available to the public via a university or EAA headquarters. I am sure we will see excellent coverage on the life and times of Mr. Bowers in a coming issue of Sport Aviation.

As for the Flybaby, it's a great design and was built in large numbers. You are quite correct that an O-290G is the wrong motor for it. It was intended to be powered by one of the small Continentals, 65-100hp. Just a note: An O-200 is 200cid and 100hp at 2750rpm; a C-85 is 85hp, 188cid, and rated at 2575rpm. The Corvair motor in its standard configuration would make an excellent motor for the Flybaby. The engine's low cost and plans built nature complement the Flybaby philosophy perfectly. Electric start would make a nice touch to make the plane easy to operate. In this configuration, it will weigh about the same as an O-200, but be far smoother. And of course, it will not require raiding your Swiss bank account.

Additional good news is that your O-290G, if it was converted correctly to an aircraft engine, is worth far more than you will spend to completely overhaul and convert a Corvair motor to flight ready status. Even a worn out O-290 will bring far more money than the wonderfully inexpensive Corvair will cost you. Welcome to the wonderful world of Corvair economics - initially hard to believe, but true.

Subj: Starter mount

Date: 6/18/03 I have a question about the new front starter mount mentioned in the Spring 2003 Corvair Flyer newsletter. I noticed in the picture that the left hand mount appears to have a tab welded to it , and the "link" is attached (bolted) to it. In the drawings on Page 9, you show a 3/8s bolt welded to the 3/4 square tubing. I am assuming that the 3/8 bolt goes into the starter mounting hole. My question is which of these two methods is the most recent? They both appear to be a much better idea than the welded 1/4 mount with the hole, from the Conversion M anual. Also, I would think that the mount with the 3/8 bolt would drop the starter an additional inch or so - is this right? Regards,

Doug Cowlthorp, CH601XL, Winnipeg Mb., Canada, thorp@escape.ca

Reply from WW:

The first generation of front starters are characterized by an aluminum angle bracket and the method shown in my Conversion Manual shows how to fabricate your own aluminum bracket. While this worked and flew many hours, with examples of it flying as far away as Australia, this is now being superseded by the mount characterized with the welded square tubing and studs as you mentioned. Just so we have terminology so everyone can be on the same page, we'll refer from now on to the early style as the original front starter, and the new model will be referred to as the low profile front starter. You have very sharp eyes, and are a good observer. The pictures above, below and on the back of The Corvair Flyer are of the prototype of the low profile starter. The drawing in The Flyer is how we're actually shipping the parts. It does have a 3/8" stud in place of the tab and bolt, and is a detail improvement. The low profile starter is a height reduction of about 1". More importantly, it's easier to fabricate and is adjustable in height, and therefore more forgiving of each individual assembly. It's slightly lighter also. I've studied the whole system in great detail, and I'm now very satisfied with it. Accordingly, I've had batches of the parts made up so I can offer kits. It's going to be the only starter system I'm putting on all the motors I build from now on.

Subj: Kolb MKIII

Date: 6/17/03 I have been flying a Kolb MKIII for several years, and have owned several Corvairs since I was 20 years old (a long time ago). My airstrip is only 750' long, and the MKIII takes off MUCH quicker with a 68" prop instead of a 64" prop. I assume that the only way to swing that big a prop with a Corvair engine is by adding a reduction drive, is this feasible? Thank you.

Richard Pike, rwpike@charter.net

Reply from WW:

I recently have thrust tested propellers as large as 72" with succesful results on direct drive Corvair engines. Although I personally prefer slightly smaller props, even on the slowest of airframes, I went out of my way to accurately thrust test a Warp Drive prop of this diameter in order to provide factual data for my customers on this. (This thrust test is included on my latest video, Corvair Engine Assembly Part I, available for $29 by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card at the FlyCorvair.com Online Catalog .) There is a bit of a misconception among homebuilders about the upper rpm limits of certain prop diameters. Keep in mind there are certified props for 2,700rpm Lycomings as large as 86" in diameter, which of course are run direct drive on aircraft with forward velocities far in excess of very light aircraft, like your Kolb. In short, each airframe/propeller/engine combination needs to be optimized as a unit, but the Corvair can certainly turn propellers direct drive as large as most homebuilt airframes can physically accommodate. Above is a photograph taken during a thrust test of the 72" Warp Drive propeller. The top gauge shows a very accurate 2708rpm static. It has a pitch setting of 9 degrees. This would be appropriate for a Pietenpol, J-3 or Stork. The RPM is measured with a digital, optical prop tach. The bottom gauge, $20, is reading in PSI. This is reading the hydraulic pressure in a hydraulic cylinder in tension, restraining the test stand from rolling forward. It is in direct line with the crankshaft. The area of the hydraulic cylinder is 1.52 square inches. Thus, the actual thrust is 380 pounds. Keep in mind that we are running stock, cast iron exhaust manifolds, and a full exhaust system with an automotive muffler for sound suppression (my hangar is in a residential airpark). Additionally, the engine has no cowl, but is using a 7"x24" air scoop 6" behind the prop. The test stand has a mock firewall, which is a blunt 30"x24" rectangle 14" behind the engine. From testing of cowled airplanes with flight exhaust systems, I can assure you that they thrust test much higher. Nonetheless, 380 pounds is a very respectable number, and would do a great job flying a J-3 sized airplane. Compare this with a C-85 powered fully cowled Cessna 140 with a 72" metal propeller pulling 385 pounds measured by myself with the exact same equipment. I've frequently heard numbers thrown about in the 500-600 pound range claimed on behalf of engines ranging from 65 to 125hp. When investigated, most of these claims don't stand up, so I would caution people not to draw conclusions when comparing numbers. Many people who have attended Corvair College have seen my test equipment and verified its accuracy.

Subj: Maximum propeller diameter

Date: 6/16/03 Thanks for your reply, William. I appreciate your thoughts on this project (Piet for Big Boys) and I do give more credence to you guys who have actually built and flown a Piet. I'm not planning to stray too far from the general proportions of the original Aircamper but I did stretch the aft fuselage for greater leverage for the increased pitching moment of the 4412 airfoil as well as increasing the vertical and horizontal tail surface areas (using a scaled up Sky Scout tail feathers profile). Of the few Piets I've flown in, I've always thought an increase in tail volume would improve directional and pitch stability even on the stock Piet. Just to clarify.... With one of your 'stock' Corvair conversions on a Big Piet your suggestion for a wooden propeller diameter is 68 inches? Any hint as to pitch recommendation? I plan on making the prop myself (education, $ savings, aesthetics, fun and satisfaction) but I always listen carefully to someone with your firsthand experience. Thanks again for your input.

Arlen Anderson, Pietenpol, Papabear108@aol.com

Reply from WW:

Prop pitch measurement varies from manufacturer to manufacturer. One man's 32" prop is not the same as another's. If you wish a high cruise of 80mph, at 2,800rpm, the following math would suggest 80mph = 7040 feet per minute 7040 x 12 = 84480 inches the plane will travel forward in one minute If you divide this amount of inches by 2,800 revolutions in the same minute, it will give you the number of inches forward motion per revolution, in this case, 30.17. This is your inches in pitch. You can work these formulas many different ways, but to absorb a certain amount of hp at a certain rpm, you need a very specific amount of blade area. An engine that's operating at 25" MAP and 2,800rpm and producing 75hp, like a Corvair, could be called Case A. Conversely, a Continental A-75 would require about 2,500rpm and 25" MAP to produce the same horsepower - Case B. But, the difference between the amount of blade area required on Case A and Case B is quite substantial. The Corvair motor would require approximately 25% less blade area to effectively transmit the same hp into thrust. This is why big, geared, slow turning props have to be much larger. If you turn props very slowly, they have to have a lot of blade area to produce thrust, the same way that if you're going to fly an airplane very slowly, it has to have a lot of wing area to produce lift. The greatest old wives' tales told in aviation by people who have never directly experimented with the engines they're willing to talk about is that the larger, slower turning prop would somehow be magically more efficient. Having owned, tested and flown all types of props, thrust tested them scientifically, and worked for or been a dealer for a number of major prop manufacturers, I can assure you this is an old wives' tale that isn't true. The 68" propeller I was referring to was a Warp Drive two blade with squared tips. A wood prop should be slightly smaller, perhaps in the range of 66". There is a lot to the art and science of wooden propeller making. I've never seen anybody on their first shot produce a wooden prop that would work anywhere near as well as a Warp Drive. Very experienced wood prop makers can slightly exceed the performance of Warp Drive with a custom made wood prop. I'm not discouraging you from manufacturing your own prop, I'm just telling you that you need to be armed with a lot of good information. Most of the stuff people publish on props is trash. If you want a good starting point, the 1930 edition of Fred Wick's book on props is the bible. And I would not attempt to build one without Hovey's book on practical prop making circa 1985.

Subj: forged piston source?

Date: 6/15/03 Are forged pistons available currently, and if so, what is the source? Also, Corvair Underground is really pushing the Ken Black hypereutectic pistons as being as detonation-resistant as forged. Are these the same hypereutectic pistons that you've already written about in the manual? Thanks much,

Jeff Boatright, Manual #5245, jboatri@emory.edu

Reply from WW:

Under no circumstances are hypereutectic pistons as detonation resistant as forged are. It is irresponsible for people to suggest that they are. The Blacks are made by United Machine and Technology, and the manufacturers do not claim them to be anywhere near as detonation resistant. The whole story on pistons was in the last issue of The Corvair Flyer. The engines I'm currently building are using the 88mm VW forged pistons from SC Performance.

Subj: Corvair in a Zodiac CH 601HDS?

Date: 6/14/03 Any thoughts or info about a Corvair in a Zodiac CH 601HDS. I'm interested in building something with a Corvair and have never built before.

Mark King, kinglabwest@earthlink.net

Reply from WW:

The Corvair/601 is a very popular combination. I'm currently working on motor mounts and other installation pieces for this combination. Keep an eye on www.FlyCorvair.com for details. Please note that most guys building today are building the XL model, a serious improvement over the earlier models. You may wish to consider this.

Subj: Wittman Tailwind

Date: 6/13/03 I have a carb from an old C-75 Continental, will it work on the Corvair? Also are there any Tailwinds you know of currently flying a Corvair engine?

Stan, Tailwind9@msn.com

Reply from WW:

There's nobody I know currently flying the Corvair/Tailwind combination, although it has flown in the past. We have several experienced builders working on the combination right now, so before long, we'll have several fresh flyers on this front. A lot of my flying time was done on an NAS carburetor, which I believe was the same carb used on the C-75. They have different venturis, but the 1 3/8" venturi has supported well over 100hp when installed on a Corvair motor.

Subj: Exhaust Stacks

Date: 6/12/03 I am interested in a set of your exhaust stacks for a 95hp engine (head numbers 3878569). Do you have any pictures of them? I have to heat the heads to remove the old stubs, how do the new ones fit? Can they be fitted with the valve etc. already in the head? Thanks.

Peter, vk3eka@yahoo.com

Reply from WW:

My exhaust stubs bolt directly onto the stock heads with their steel stacks in place. They are not a replacement for the stock piece, they are the beginning of your exhaust system. We will have more pictures next week on the Online Catalog at www.flycorvair.com. We're revamping this right now. It will have much better explanations, and they'll be much easier to see. The stock exhaust stacks can generally be removed from the head without heating the the head. I'll post a picture of the lever mechanism I've used to pull hundreds of stacks from heads. You only need to do this if you have bad stacks. My exhaust stubs will bolt right onto original exhaust stacks.

Subj: CORVAIR FLYERS

Date: 6/11/03 IS THERE A WEB SITE FOR CORVAIR FLYERS?? THANK YOU FOR MESSAGE ABOUT ZENITHAIR 701 & CORVAIR. HAVE MY WINGS & RUDDER DONE.THANKS.

MAX BUTLER, ZENITHAIR 701, CHEYENNE,WY, MB160016@exchange.DAYTONOH.NCR.com

Reply from WW:

If you would like to see a partial collection and information about flying Corvair planes, just check out this new part of our web site: Flying Corvair Planes!. It's a work in progress, and we're trying to add to it all the time. Check it frequently for updates, as the results of our Corvair Questionnaire continue to return from all parts of the country. This is my favorite part of the Web site because it's a pleasure to admire the craftsmanship of these builders and aviators. It should fill the rest of us with motivation to go out and complete our Corvair powered birds, taking our rightful place amongst the group of builders now enjoying the fruits of their labor and the freedom it gives them.

Subj: Engine to prop

Date: 6/10/03 Can the engine main withstand the prop torque? Any possibility of a super charger for added power?

jchelmecki@aero.net

Reply from WW:

I assume you're speaking of the main bearings of the motor, specifically the thrust bearing in the engine. The Corvair motor has a double sided main thrust bearing, which has a perfect track record during the past four decades of powering the aircraft. You can find the complete story further down this page by hitting Ctrl+F and typing in "bearing." In short, the motor needs no external thrust bearing in a direct drive application. I'm currently working on a turbo charger to boost the power of the application. More details as they develop.

Subj: Metal plane to match Corvair, of course

Date: 6/9/03 I have been surfing your site for an hour and am excited to think that the Corvair engine is what I am looking for, inexpensive and reliable. I have not settled on a plane, other than I want to make it out of aluminum, as I am a machinist with a shop and am comfortable with metal. I will beg your indulgence and ask for your opinion about just what kit plane to make. Fast would be nice, but I am realistic about that. Something matched to the motor makes sense to me. I am located just NE of Orlando, and would like to come over for a class about working with the Corvair engine. Thanks in advance,

Terry Warburton, Geneva, Fla.

Reply from WW:

Welcome to the club. There are a number of metal aircraft designs that match the Corvair very well. If you're interested in a single seat design, Kevin Bishop's Ellesay is currently heavily into the prototype stage, and it was specifically designed for Corvair power. Amongst two-seaters, the Zenair 601 is very popular with Corvair builders. Neil Hulin is our point man on the Corvair-601 project. I am developing the installation for his 601XL project, but there are many, many other guys in the field working from my Conversion Manual on the exact same match. Feel free to stop by at any time, just call first to make sure we're here. We travel to airshows, fly-ins and EAA Chapter meetings quite a bit, but are always ready to play host to anyone here to learn.

Subj: Replacing crankcase studs

Date: 6/8/03 I have a question regarding the replacement of crankcase studs. I purchased a motor from an individual who pulled it from his car and stated it had a blown head gasket. After teardown I could not find any evidence, although I am not sure what a blown gasket would look like, they look fine to me. However, when I was removing the heads I did notice three of the stud nuts in the area of one of the center cylinders did not seem to have as much torque. About half a turn and they were free. The area around the base of this cylinder was also very dirty/oily as compared to rest of engine. To be on the safe side I thought I would go ahead and helicoil all the studs. My question is, after helicoiling can I reuse my studs? The green shop manual mentions studs are available in .003 and .006 oversize. Clark's catalog says to use .006 if you helicoil. Also, do you torque the studs the same when using helicoils? Thanks.

Mark Sandidge, Madisonville, Ky.

Reply from WW:

Yours is an excellent technical question. The sign of a blown head gasket is some of what you described, plus obvious blow by at the top of the cylinder. I would not assume just because it had a blown head gasket that it was pulling the studs out of the case. Careful inspection is in order. Take a straight edge and compare the height of all the studs. They should be within 1/16" of each other. If none of them unscrewed on disassembly and they're all about the same height, and there's no obvious defects, your blown head gasket may not have damaged the studs. Clark's is a good outfit, but they are mistaken on this one issue of studs. As stated in the Conversion Manual, the thread on the stud is NC5-16, not 3/8-16 like a helicoil. Use the split die method outlined in the Conversion Manual (available for $59 in the U.S., or $64 including S&H outside the U.S., by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog) if you are helicoiling and use the stock size studs. A stud that screws into place when using helicoils must be locked down using thread locker. My preferred LocTite is 620. A stock stud is like a pipe thread in that it bottoms out at some point. Any helicoiled hole is like a nut and a bolt.

Subj: Usable heads?

Date: 6/7/03 I have just recieved two engines from the US. They are: Motor 1 RU with 8049 crank and 3880708 Heads; Motor 2 is an RG with 8049 crank and 3878569 heads. The RU is in better condition. Your Manual states that both are unsuitable (page 19), yet page 46/47 says the 3878569 heads are OK. Could I use these heads on either engine? If so, I presume I would only need another set of suitable heads for the second engine. By the way, I have now moved from St. Helena back to Australia; much better airplane building environment! Thanks for your time.

Peter, Australia, vk3eka@yahoo.com

Reply from WW:

Both of your blocks came from the factory with something called AIR installed as a system on the engine. AIR is not air conditioning, but rather emissions control equipment. Stripped of their external paraphernalia, the only thing about these engines that would then be unsuitable for flight would be their no quench area combustion chambers. You are correct that acceptable heads could simply be swapped onto these motors. As evidence, this already has been done on the engine you referred to as Motor 1. The 0708 heads did not come on the RU motor from the factory. But, they are excellent heads for a flight conversion. In short, Motor 1 is ready to go. There is some debate about the heads on Motor 2. The 8569 heads are listed as 8.25:1 compression, and I think they probably have a quench area and are suitable for flying. Complete open chamber heads, such as the turbo heads, are the ones that are not suitable for flying. GM literature lists these as 8:1 compression heads. A 3883862 is an example of a 95hp open chamber head. All you have to do to verify that Motor 2 is ready is check for the quench area in the combustion chambers. Congratulations on getting two good core engines to the other side of the earth. This goes a long way to prove that anybody who wants Corvair power for their experimental aircraft can readily have it. Certainly everyone in North America can readily find a motor if they want to.

Subj: Pietenpol Power Curve, Props

Date: 6/6/03 My nephew & I are researching the possibility of using a Corvair engine on a Pietenpol. Do you have available the power curve on the engines?? What prop would you recommend?? Thanks.

Harry Myers, harrymyr@vtc.net

Reply from WW:

As you already know, the Corvair is the ideal engine for the Pietenpol. The updated long fuselage drawings available from the Pietenpol family are the most ideal ones to build from for Corvair power. The Corvair engine, built according to my Conversion Manual (available for $59 in the U.S. (and $64 including S&H outside the U.S.), by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog) produces about 80hp at 2,800rpm, 90hp at 2,950 and 100hp at 3,100rpm. I sell 2-blade Warp Drive 68" ground adjustable propellers for Pietenpols, the same prop I flew for years on my own Pietenpol with great satisfaction. Most guys flying wood props use 66" diameter with a pitch in the range of 30-34". Happy building and flying your family project.

Subj: How Sweet it is!!!

Date: 6/5/03 As you are aware, I am running the 32mm Aerocarb on my engine. The engine, prior to yesterday, had 7 hours running time on it. One of the things I had been having trouble with was low idle rpm. I simply could not get the engine to stay running below 1000 rpm. I was beginning to think that the 32mm carb was not right for this engine and I might need a 35mm. So, I decided to study the manual on the carb again and see if there was anything out of the ordinary I was doing. The manual stated the carb comes with three needles for proper tuning to the engine. Number one is leanest, number 3 is mid range and number 5 is richest. So I got to thinking about this, and it seemed to me at low idle I simply could not get enough fuel to the engine to keep it running. I took a look at the two spare needles I had and they were #1 and #3 so I decided to remove the one in the carb to see what number it was and it turned out to be a #2. Well what do you know, I installed the #3 and followed the instructions on tuning the carb, hit the starter, and she fired right up. I allowed her to warm up at 1000rpm then began to slowly lower the rpm and reached 600rpm. I was awestruck. This engine was purring like a kitten at 600rpm with absolutely no vibration. I simply could not believe the performance I was getting now that I installed a needle which gave me a richer mixture at idle. Once again I am on top of the world with excitement about the Corvair engine and I would like to thank both you William and Grace Ellen for all you guys have done to get me to this stage. Also, I hope a visit to my house is in your plan when you visit Broadhead and Oshkosh this summer. I have bragging rights you know and you must see how I have progressed since you were here last summer. How Sweet It Is !!!

Mark Jones, KR2S N886MJ, Wales, Wisc., flykr2s@wi.rr.com; Visit my KR-2S CorvAIRCRAFT web site at http://mywebpage.netscape.com/n886mj/homepage.html

Reply from WW:

Great to hear from you. There comes a point in every man's building where he must break down and suffer the ultimate humiliation of actually reading the directions. I myself am frequently forced into this position. The photos on your Web site do show the great progress. Glad to hear the 32mm Aerocarb is working out for you. Certainly is a quality piece. We're planning on being at both Brodhead and Oshkosh, and we'll certainly stop in on the way, weather permitting. You're not far off our path. Thank you kindly for the invite and the update.

Subj: Wag-a-bond Power

Date: 6/4/03 I am building a Wagaero Wag-a-bond from plans. Fuselage welded and tail feathers. Was thinking of powering with a C-85 or O-200, however looking at the Corvair engine; this might be the way to go. Is the Corvair College still operating? I spend my winters ( Oct. - April ) in Hudson, Fla., and may attend the college next fall or winter if it is available.

Carl Rivait, Wag-a-bond, Hudson, Fla., rivaitca@earthlink.net

Reply from WW:

Here's how good a combination I think the Corvair and Wagabond is: I'm building one myself. I have a completely welded fuselage that has been modified from a damaged Colt. The Wag-Aero plans set fuselage is more closely related to a Colt than a Vagabond. I work on it a couple hours every day with the intention of getting it flying by the end of summer. We'll post pictures of it on FlyCorvair.com shortly. Corvair College includes many classes throughout the year, but the big one is in the spring during Sun 'N Fun. You're always welcome to bring your stuff and come by the hangar.

Subj: Starter Kit Prices

Date: 6/3/03 I noticed a reference in passing in your web Q&A that you now have starter ring gears and are looking at stocking complete starter kits. Hey, sign me up. Anything I can get from you I'll buy. The payoff for me is that I don't need to stop building the aircraft in order to run around town sourcing all these bits and pieces. Let me know the extra cost and I'll get a cheque in the mail.

Neil Hulin, Zenith 601HD, Cincinatti, Ohio, nhulin@hotmail.com

Reply from WW:

We have a good supply of the starter kits in stock now because we did all the running around and lots of it for you, and the rest of the gang. Here's the breakdown on the prices, which include U.S. shipping: Bracket set, $79 New lightweight ring gear with all machine work done, $89 Puck, $189 Alternator pulley with all machine work done, $59 Replacement Subaru starter gear, $20 These introductory prices include U.S. shipping until Oshkosh.

Subj: Is this a good candiate? Short time window - please answer soon

Date: 6/2/03 I recently came across this item for sale: "Corvair 102 H.P. Engine with 94,000 original miles that was removed from my now turbocharged 1962 convertible just 3 months ago. I decided that since I wanted a bit more umph! a turbo would do the trick but had to replace the entire engine. You cannot just turbo charge a standard engine without rebuilding it to turbo specs. The engine is 99+% complete and only missing the mount for the oil filter-readily available. Everything else is there and functions fine. The only glitch is that there is some blowby but no smoke from the tail pipe. The carbs were just recently rebuilt and the engine starts with very little effort. Once started, it has never stalled unless it was my sloppy clutching." The case is stamped T0615YN, for whatever that's worth. Is this a good candidate for conversion? It looks like a heckuva deal. The shipping cost from the Gulf coast to Minnesota may be more than the cost of the engine itself. There's a very short window of opportunity, so I'd really appreciate a quick answer. Regards,

Corrie Bergeron, Minnesota, corrie@itasca.net

Reply from WW:

A 102 is an early model motor, and is only 145cid. It is not a good candidate for a flight engine. The 1964-69 motors are all 164cid and have a few internal differences that make them better motors. I would pass up a deal on any early motor. It's not worth your time to pursue them. There are plenty of 164cid motors to go around. My Corvair Conversion Manual, available for $59 in the U.S. (and $64 including S&H outside the U.S.) by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog, contains all the numbers, codes, etc. so you can get the right engine for your project.

Subj: Heads

Date: 6/1/03 Can I use a 3813513 head on one side and a 3856759 head on the other side? Thanks.

Jim Daron, Pietenpol, Manual # 5498, Malabar, Fla., cjdaron@cfl.rr.com

Reply from WW:

The 513 head is from an early model 80hp and cannot be used with the other head, which is a good one for your conversion. The 759 uses the 1965-69 cylinder, so make sure you find another '65-69 head to match it.

Subj: Case and Crank

Date: 5/31/03 I've torn my engine down to parts, excepting three really ugly case studs which I hope to get done this weekend at a borrowed drill press. Unfortunately, my outside studs were bad enough on the tops to forget any possibility of reusing them, so I decided I'd rather change them all and know what I have.

I'll probably be looking to send my crank your way after verifying some measurements once I get the service manual. I saw on somebody's Web site that you have a shipping box designed for the task, so what is the usual protocol for doing this? Thanks,

Clay "Hoppy" Hopperdietzel, Zenith 601HDS, Tomball, Texas, hoppy@houston.rr.com

Reply from WW:

Got your phone message. Almost all cranks will clean up with a 10-10 regrind. In land based applications, cranks are commonly reground much more than this in high performance apps. But I only recommend things I've personally flown, and therefore, 10-10. I used to ship the cranks in specially made wooden cases. But UPS continuously damaged the cases in a way that they appeared to have been dropped consistently from 3 or 4 feet. Today we ship cranks wrapped in plastic, rolled in a large beach towel, wrapped in bubble wrap, in a cardboard box, by USPS. Seems to work better. If you're building a 3100cc motor, keep in mind that you cannot helicoil any of the stud holes in the case. Be cautious when removing and replacing studs in a potential 3100cc engine for this reason.

Subj: Bushmaster

Date: 5/30/03 I am writing you to settle my dispute with myself over the Corvair. I fly a Bushmaster and really want to do the 4-stroke conversion. Lots of people that I know have installed the Subaru in them and they work great. The Subaru weighs about the same installed wet, but is very expensive to build with a reduction. My question is: If I install the Corvair with direct drive, what can I expect for performance? Will this plane be good on floats? I have been following your stuff for a while, but have not seen a plane similiar to mine yet that has this conversion. My dad is Murray Green. He is very close to having his Stork completed with the Corvair, but I can't wait that long to see how his reacts. Plus his is very high lift. I thank you for any information you can give me to get me on my way.

Mike, shannon.l@vcm.ca

Reply from WW:

We've recently done a lot of very accurate thrust testing on the Corvair, turning a 72" Warp Drive prop. This was done to satisfy the curiosity many people have about the direct drive turning a much larger prop. The engine produced nearly 400lbs. of static thrust for a pitch setting that would be appropriate for an 85mph cruise. This was running the engine with no cowling, a blunt air scoop, and a flat 30x24" firewall behind the motor. The engine also was run with complete cast iron exhaust system and a large muffler for noise abatement reasons. It static'd the Warp Drive prop at 2700. Even at this rpm, the thin Warp Drive blade sections were not excessively noisey. In short, I think the engine would be very appropriate for your aircraft.

Subj: Pulley p/n

Date: 5/29/03 To those using the front mount starter & alt setup per Mr. Wynne's plans, the p/n for the GM pulley has been changed from 3927116-AV to 14087008. You can find new pulleys on the web for $6 + $7 S&H. I purchased mine for $10 from the local GM dealer. Just an FYI. The puck is complete onto the prop adapter.

Al Manley, Longmont, Colo., amanley@attglobal.net

Reply from WW:

Nice piece of homework. Seriously, you win the award for best customer supplied information this month. And the award is: a free one-year subscription to The Corvair Flyer newsletter. We're working in the hangar right now, and decided to institute this new award based on the fact I was having a very difficult time tracking down the new pulley number myself. This is a very good example of how everyone has something to contribute, and why we refer to the Corvair as a movement of friends, as opposed to merely our business.

Subj: Kit Plane dude

Date: 5/28/03 I saw your story in the latest Kit Plane mag.

Brent Brown, Autogyro, Fayetteville, N.C., brownb@soc.mil

Reply from WW:

Thank you.

Subj: Oshkosh

Date: 5/27/03 Will you be at Oshkosh this year? If you are, and I ordered some stuff from you, would it be possible to pick it up at Oshkosh? Items would be Conversion Manual, Aluminum CNC top cover and possibly a crankshaft. All will be paid for before Oshkosh. I have just got my engine, a 110hp with all the right numbers. It's going into a GN1. Thanks,

Ken Rickards, GN1, Markham, Ontario, krickards@CVCI.com

Reply from WW:

If we were driving to Oshkosh, I would gladly accommodate your request. However, this year, the plan is to fly by Taylorcraft. It's a 1946 BC12D which has a gross weight of only 1,200lbs. We'll be cutting it close enough with a week's worth of camping gear and the normal products I bring to sell at airshows (Manuals, Videos, Top Covers, Hybrid Studs, Safety Shafts, Oil Pans, etc.). If you have a U.S. address you'd like us to ship to in Oshkosh, perhaps we could save you the across the border fees. A quick reminder on crankshafts: I do them only on an exchange basis. You get your exact crankshaft back. I did about 100 cranks last year, and got only about half the cores back. This year, I'm making a special effort to ensure everyone gets their exact crank back instead of the exchange and core program I ran last year. You can check the EAA's Web site, AirVenture Forums, for the latest schedule. So far, I am scheduled to speak on Converting Corvair Engines 7-8:15p.m. Wednesday, July 30, in the Aircraft Shopper Online Pavilion 5. Check the AirVenture Forums site later for more dates.

Subj: Hybrid torque

Date: 5/26/03 How much torque should I use on the studs going into the crankshaft???

Larry Baxter, Manual #5124, Adelanto, Calif., ssshvac@msn.com

Reply from WW:

The studs should be double-nutted and torqued into the crankshaft at 22-24 foot pounds of torque, lubricated only by LocTite. Remember to clean off all excessive LocTite after they're torqued in place. The LocTite I recommend is 620. It's expensive, but it's more heat resistant than the regular red LocTite. Please note that we haven't had any problems with the red LocTite, but are still switching to 620 now.

Subj: Fuel octane

Date: 5/25/03 Mark Langford's Web site said he'd burn lower octane fuel in the 3,100cc motor. Is this possible?

Gordon Alexander, Shakopee, Minn.

Reply from WW:

Yes, this is possible. The first person to fly the 3,100cc motor, our friend Steve Makish in South Florida, tested all types of fuel and his compression ratio lowered in a method similar to Mark's. I'm pretty sure that when we broke Mark's motor in at Corvair College #3, we used 100 percent av gas. Although Mark's Web site may not reflect this, I had a phone conversation with him a few months ago in which he explained that after a long discussion with a fuel expert, he's pretty much sold on operating his airplane on 100 percent av gas for many operational reasons beyond mechanical compression ratio. Many people know I'm a fan of 100 low lead, and the technical discussion surrounding this is in the latest copy of the Conversion Manual, available for $59 in the U.S. ($64 including S&H outside the U.S.), by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog.

Subj: Cozy or LongEZ

Date: 5/24/03 Would the Corvair be a good choice for the Cozy Classic or the LongEZ.

Yosef, y_kristos@yahoo.com

Reply from WW:

I believe that the Corvair is a poor choice in either of these aircraft. The only combination I would consider would be a 190cid engine in a LongEZ that was built to Burt Rutan's concept of a very light day VFR airplane. Although these aircraft are thought of as being efficient, they almost exclusively use engines far more powerful than the Corvair. Many pusher canard aircraft have extremely high stall speeds for a single engine plane (they cannot utilize flaps). This high landing speed, combined with the engine's mass behind the passenger compartment, works against your safety in an engine out situation. The logical argument here might be for utilizing only the absolutely most reliable engines operated at their least percent of power output in these aircraft. To me, that would be a large, brand new Lycoming.

Subj: Camshaft bore?

Date: 5/23/03 We just finished tearing down and cleaning two 110 engines. These two engines and one other have pitting in the camshaft bore. How much pitting is allowed if at all? Do you recommend crocus cloth for light pits and buildup and rebore for deeper pits? I would appreciate your input. Best regards,

Paul Mallard, Miami, Fla., papaquack@aol.com

Reply from WW:

There are a lot of old wives' tales about Corvairs wearing out the camshaft bores. This may be an issue for guys building 8,000rpm race engines which will have cam profiles that will require enormous spring pressure on the valves, but for our application, I have found virtually all Corvair cam bores I have inspected usable. Light pitting would not bother me, as the bearing area is very generous. I would be hesitant about any technique that would lead to material removal, such as any real sanding, etc. If you truly have the rare case with a damaged bearing bore, I would just find another case. The value of a case is about $50, and there's no conceivable technique to rework one which would cost less than buying four or five spares. A good indication that this has not proven to be a problem in Corvairs is the fact that there really are no methods of reworking this area in the engine. If Corvairs damaged their cam bearing bores frequently, or if the cases were highly valuable like aircraft engines, there would be techniques such as line boring or oversize cam blanks readily available. With the reliability of a Corvair, there's never been a need to develop these. We recently had a visitor to the hangar who was nothing short of amazed that there are no cam bearings in the motor. He expressed some degree of wonder at whether or not this brought into question using the engine in an aircraft application. He was even more stunned to learn that no Lycomings or Continentals have cam bearings either, and they have a pretty good record as airplane engines go.

Subj: Corvair in an Osprey?

Date: 5/22/03 I attended your seminar at Lakeland and bought a Manual, No. 5545, and a video and would like to build a Corvair engine. I have bought an Osprey project in Miami and it needs an O-320 to have enough power. I know in your book you mention that the Corvair is not capable of that much power, only 120hp with the large cylinders. I just wondered if you had any ideas for a few more hp, i.e. Rinker box or maybe turbo, stroker, maybe even a direct drives oldsS. I have successfully converted a Mazda which is flying in a Grumman every day, but I don't want to do that again as it was a major pain in the ass and I don't like that gearbox. Kindest regards,

Bill Fisher, wfisher5@bellsouth.net

Reply from WW:

I don't believe the Corvair motor in a simple reliable form can be used to power an Osprey II. An Opsrey is a high performance amphibian with very high wing loading, especially for an amphibian. Most people conclude that an O-320 is the minimum engine. Corvairs have been flown in their large displacement form, with gearboxes and turboed. But I feel that if you combine all of these elements in a single motor, it would start to get as expensive as an O-320, yet would not posess the simplicity and reliability of a run-of-the-mill O-320. It's very hard to get a 164cid engine to do the work of a 320cid engine. And it certainly cannot be done inexpensively and reliably. All of the issues you mentioned with the difficulty converting your previous project, with liquid cooling, gearboxes, etc., are the reason why I focus all of my work on a simple, direct drive, air-cooled engine.

Subj: Your Corvair engine for sale

Date: 5/21/03 I was lucky coming across your adv on Net concerning your Corvair engine of which I've been searching for, with the price of $2,700. Could you please send the pics and tell the condition of the engine so I can make an arrangement for the payment asap.Thanks.

jcbrazaville@yahoo.com

Reply from WW:

I am not sure what Web site still lists this, but the engine was sold several years ago to John Martindale in Australia, who is now flying it in a KR2. The good news is that you can build one yourself for less than $2,700. You start with a Conversion Manual, which will guide you through finding a core motor (not a difficult task) all the way through its conversion and installation. I highly recommend against buying engines offered for sale which are already converted. Very few of these crop up, and in almost all cases, they are converted by people with very low levels of craftsmanship who would be afraid to fly it themselves but would unconscionably offer it for sale so someone else could fly it. The best approach is to build your own motor for yourself. It's what all the succesful builders are doing. Start with the Conversion Manual, available for $59 in the U.S. ($64 including S&H outside the U.S.), by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog, which also lists all the products you would need for the conversion.

Subj: 95 HP or more?

Date: 5/20/03 William, Before I purchase your Conversion Manual I want to know if I'm going in the correct direction. Just purchased a $100.00 1968/69 95HP (no smog) engine. 1. Will the HP vs weight be ok for my KR2S? 2. If needed can I increase HP with new jugs and still use the heads. I have experience rebuilding several auto engines including many VW engines. If the 95 HP will work I will be ordering your Conversion Manual.

Steven Phillabaum, KR2S, Auburn, Alabama, skphil@charter.net

Reply from WW:

Your late model 95 no-smog engine is the perfect candidate for a KR2/KR2S conversion. We have four KR2s flying now on Corvair power. I think the 2S will be an even more impressive aircraft. All the options of different jugs are available with your motor, but even a basic rebuild and conversion will provide outstanding performance. Additionally, the KR2 is one of the most popular Corvair conversions. I have sold hundreds of Conversion Manuals to people who are now working on this. I've developed and have jigs and tooling for motor mounts, etc., and have spent a significant amount of time to integrate the entire package to make it an easier installation. I went through all of this effort because it is such a good match, and I expect to see a lot more of them take wing this year. The Conversion Manual is available for $59 in the U.S., $74 for international builders, including CANADA, by check or money order in USD payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the FlyCorvair.Com Online Catalog.

Subj: Sportsman 2+2

Date: 5/19/03 I only have read info on the Sportsman 2+2 in Aerocrafter and it lists an O-290 with 135 hp. I have not been able to find weights for this engine but it seems at a glance this could enable a Corvair O-190 fit as there should be a little weight savings. What do you think?

Scott Schermerhorn, Schermerhorn.Scott@delcoremy.com

Reply from WW:

A Sportsman 2+2 is a homebuilt replica of a Piper PA-14. The replicas tend to be heavier than the original, and the original was something less than an exciting performer with a medium-size Lycoming. Today, most Sportsmans are built with 180hp Lycomings. An O-290 Lycoming is 290cid and it produces its rated power at 2,700rpm. A direct drive O-190 Corvair could produce the same hp, but it would require much higher rpm, which would necessitate a far smaller propeller. This small propeller would not be a disadvantage on a sleek, small airplane like a KR, but it would not as effectively turn hp into thrust at low speed required for a Sportsman. Thus, the Corvair is not an effective replacement for an O-290, especially in larger, heavier airplanes. If you like the Sportsman, you should consider the two-place version: The Wagabond. It is an excellent match for the Corvair, and we have at least two people currently working on them. The Wagabond's original intention was for 100-120hp, which makes it right up the Corvair's alley.

Subj: Selling the Q-200, 'Vair in a Tailwind?

Date: 5/18/03 I have decided to either sell or abandon my Q-200 project for now. I've opted for a Tailwind instead. What do you think about a Corvair in one of these? They have flown on a wide variety of motors, so I think it would be most suitable. I've also been thinking, since they can handle the weight, of turbo-normalizing or even 3-5 psi above SLP. What would you think of this? How much power could you guestimate I'd get with this setup? Finally, which heads should I use? Thank you!!

Chris McAtee, subcanis@hotmail.com

Reply from WW:

The Tailwind is an incredibly good airplane. It is celebrating its 50th anniversary this year. But it is by no means a stagnant design, as major updates were done on the design as recently as the 1980s. I was lucky enough to fly with Steve Wittman in his own personal Tailwind, N37SW. The Tailwind, when built right, is a stunning performer of efficiency. While a Tailwind might be a few mph slower on the same hp, the Tailwind's advantages of a 20mph lower landing speed, the ability to fly off grass, and handling qualities that can be matched by few light planes (which a Q-200 could never hope to match) in my opinion make it a better choice. All turbo work without constant speed props is boosted, not turbo normalized. I've done some homework on this, and I feel that the best heads would be the same heads I recommend in the Conversion Manual (available for $59 in the U.S., $74 for international builders, including CANADA, by check or money order in USD payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the FlyCorvair.Com Online Catalog). I would not use the factory turbo heads. With the right turbo, and low boost, you could easily get 120hp. But the real key would be that you could still have 100hp at 10,000 or so. By the way, Wittman's airplane that I flew in had the direct drive Olds engine in it. It had a 62" prop that was a cut down prop from an O-200 (this is a bad idea - Don't Even Think About IT). But importantly, the prop turned 3,500 in cruise and produced a lot of efficient thrust. This was the handiwork of Steve Wittman, the acknowledged master of light aircraft efficiency, at his best. When you encounter people who tell you that props should never be spun over 2,500rpm for efficiency, that's their opinion against the experience of men like Steve Wittman. I know which is more valuable.

Subj: Props

Date: 5/17/03 I really hate to ask this question but I know nothing about props. I have a 68" three-blade Warp Drive prop I purchased through Zenith in a FWF package for the Subaru. Can I use this prop on the Corvair with opposite rotation? I e-mailed Warp Drive but did not get a response. I also asked them if I need another prop could I trade in the one I have as it has never been run. I know you are a distributor and was wondering if you could help. Thanks.

Mark Sandidge, MSandidge@PeabodyEnergy.com

Reply from WW:

I know the guys at Warp Drive very well, and they're usually very good about responding. You probably caught them at a busy point. As long as the equipment is brand new, they may be open-minded about a trade in. Doesn't hurt to ask. I was unaware that Zenith had packages for the Subaru. They do have them for the Jabiru, which is a different engine. In either case, right- and left-hand rotation motors require different propellers. On a Warp Drive, the blades are interchangable so you can keep the same hub, and replace only the blades. It's educational to go to the airport, look at a propeller and picture why it cannot be used on a motor of opposite rotation, even if you turned it around backwards. In any case, the right prop makes all the difference on any engine installation, and I'll be glad to work with you to ensure you get it sorted out.

Subj: Front Starter

Date: 5/16/03 I like the simple, improved front mount starter system from the Spring 2003 Corvair Flyer. I purchased the FRA235 and took it to a machine shop to have the center hole enlarged to 3.000". In their opinion, there is not enough space left for drilling more holes. I don't have a puck to verify the placement of the 6 AN3 holes. Could you clarify this for me please? Also, I have checked all the major auto parts stores here in Wichita and I'm not having any luck locating the fine tooth gear (Accurate Part No. 4-1001). Could you give me an e-mail address or phone no. on this item please? I did e-mail you yesterday about ordering a puck [Received the order last Saturday. You should have received my core distributor by now also. Give me a part number and a price and I'll order a puck. Thanks in advance.]. I think if I had a puck my questions about the ring gear would be answered. Thanks again for all your help,

Barrett Knoll, Pietenpol, Wichita, Kansas, dknoll@cox.net

Reply from WW:

You may have missed the Winter 2003 Corvair Flyer which included a drawing of the puck that showed the 6 AN3 holes will fit with plenty of room to spare. My puck part number is FS-1. The price is $189, which includes priority, insured S&H in the U.S. (please add $15 for international S&H, including CANADA). The puck is the only expensive part in my front starter system. It's made for us on a CNC lathe to very exact standards by an aircraft manufacturer. I have pulled together all the other parts so I can offer the complete front starter kit or any part of it. The fine-tooth starter gear is in stock, and it costs $22. Its part number is FS-3. Likewise, I have completely machined ring gears, etc. I'm collecting all the drawings and some very nice installation photos into an info pack. I'll post this on the Web site next week. Please check the www.flycorvair.com News from The Corvair Authority page for details.

Subj: Second Corvair Manual (For a friend this time)

Date: 5/15/03 Dear Mr. Wynne, (Sounds so formal.... ahem...) Anyway, this is Richard Alps, and you very kindly sent me one of your Manuals. Thanks. It is great! I was going to say supurb, but I can't spell that word. I am currently reading the Manual, digesting it slowly, along with trips to the internet to peruse various CORSA and TCA and KR sites. Loads of info! Whew. I may (or may not) have mentioned that I have a friend who is equally interested in aviation, and I have shared the Corvair thing with him. By the way, his name is Ray Green. He lives around the block from me, and has proved to be a trusted and invaluable friend. These kind are rare, as I am sure you know. Anyway, Ray tells me that he is very interested in the Pietenpol Aircamper and/or Sky Scout. I have pics of your Piet, and the story with it. Nuff said about that. Just the same, the Piet is a beautiful little parasol, and you gotta love the design. So, you will find PAY PAL has sent you another $59 to cover Manual #2. He is sitting here as I type this letter to you right now. I just want somehow to clarify that each of us has a legal Manual, and are authorized to associate with the TCA company and all the functions you have put into it. In closing, allow me to say thanks for all the work you have provided for the rest of us. Sincerely,

Richard G. Alps, Littleton, Colo., Richardalps@aol.com

Reply from WW:

Good to hear from you. Thank you for the kind words. People saying nice things about us when we're not there is our primary form of advertisement. Thank you very much for your efforts. Please tell your friend that we recently got a lot of new photos of Pietenpol projects that have been flying for years on Corvair power, including a Sky Scout. We'll post these on flycorvair.com shortly.

Subj: Simplicity

Date: 5/14/03 Just this very morning I read your piece in The Experimenter magazine [published by the EAA] and I thought you'd appreciate a piece of wisdom a friend of mine preaches and practices. He's made a living for years installing and servicing marine electronics and electrical systems and says: "If you don't install it it can't break." His own boat is simple and rugged as a rock and so he gets to spend a lot more time on the water than most of the people he works for. I'm a real fan of your philosophy and writing. Please keep up the good work.

Oscar Lind, Seattle, Wash.

Reply from WW:

Thank you for the kind words. The ethic of worshiping simplicity is really the key not only to building airplanes quickly, but also operating them safely. Although I didn't say it in the article, most builders are capable of producing an airplane complicated enough that they could not stay ahead of it in the cockpit. Conversely, I'm much more happy to be a real good stick and rudder pilot who's the master of my simple ship under all circumstances.

Subj: 140 HP Corsa engine

Date: 5/13/03 I have a 140HP Corvair Corsa engine, would this engine work for conversion?

Stan, lguco063@msn.com

Reply from WW:

Although this issue is covered in detail in the Conversion Manual, available for $59 in the U.S. (add $15 for international S&H, including CANADA please) by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the FlyCorvair.Com Online Catalog, I'll give you the quick overview here. The 140hp Corvair motor, distinguished by having two carburetors bolted to each cylinder head, is a high rpm motor which makes its power at an rpm not usable in a direct drive application. Additionally, it is the only Corvair motor with a reputation for poor valve seat reliability. Approximately 5 percent of the Corvairs made from 1965 to 1969 came equipped with this engine.

Though the 140 is frequently referred to as the Corsa engine, many of these motors went into cars which were equipped with automatic transmissions (all Corsas had manual transmissions). When the 140 is installed with an automatic, it is given a special 4 degree retarded crank gear that needs to be replaced if this crank is to be used for flight applications.

Everything on a 140 motor, with the exception of the heads, can be used to make a good flight motor. The heads and carburetors are worth several hundred dollars to Corvair car collectors. They would gladly provide you with an excellent set of 95 or 110 heads, which will bolt right on to the rest of the 140 motor. Again, the Conversion Manual has the story in greater detail. This is just an overview.

Subj: Smog Head?

Date: 5/12/03 William, your Manual list heads with the number 3878569 as acceptable to use for conversion. However, Clark's manual lists this head number as a smog head. Please clear up the confusion.

I was able to find two complete engines with all of the correct designations according to your Manual. The seller included the following engines: 1) a turbo case number T0708, head 3856638, and crank 8409; 2) an engine case number T1004 ZF, head with number 3813516, crank number not 8409. My question, are any parts useable from these engines?

Paul Mallard, Miami, Fla., papaquack@aol.com

Reply from WW:

I do not believe that the 3878569 cylinder head is an open chambered design. The open chambered heads, which have no quench area, are the unacceptable heads. While the particular engine it came from may have been considered a smog motor, I believe this particular head is usable. The final decision point is cylinder heads which have a quench area are airworthy, and open chambered designs are not.

The ZF case could be a number of different motors from 1961-1964. If it is a 1964, and it is relieved for a long stroke crank, it would be usable. It is probably not a relieved case if it has a non-8409 crank. Your turbo motor is a 1964 150hp. Everything on this motor is usable, except the cylinder heads (see the e-mail below on 5/4/3).

Subj: Help finding engine

Date: 5/11/03 I want to thank you as today I have received the Corvair Manual. Tomorrow I will start the procedure/gathering of information towards importing a Corvair engine into Brazil. If at the end I find that this import is possible/legal, could you help me find a suitable engine? FYI, as I work for the Brazilian flag carrier (VARIG AIRLINES), I travel a lot to the Miami area, so it would be relatively easy for me to forward the engine to Brazil. When the engine happened to be be ready for shipment, I would show up at your hangar, pick-up the crated engine, take it to Miami Airport and dispatch it home myself. At a later date, I would bring you the original crankshaft for the exchange for your modified one, and other necessary parts. Thanx in advance. Best Regards,

Oswaldo, Rio de Janeiro, Brazil, oswaldo10@globo.com

Reply from WW:

Corvair motors seem to be getting popular in Brazil (Please see 5/8/03 e-mail below). If it is not possible to find a motor, given a little bit of time, I can find you an excellent core to begin with. I have sent them as far as England and Australia. When I export a core, I like to take the time to find a near perfect one to avoid international builders having a problem that might be small here, but harder to fix there.

Over the years, I've probably sold a dozen Conversion Manuals to homebuilders in Brazil. The Ximango motor gliders are imported to the U.S. through our airport here, Spruce Creek, and our friends speak very highly of the time they've spent in your country. We can certainly handle your needs.

Subj: Spacer for Hand Propping

Date: 5/10/03 If the electric starter is left off of the engine (Armstrong starter system to save weight), is a spacer needed under the prop hub? If so, who sells one; you, I hope?

Joe Hemmer, Orangevale, Calif., kiote@cwnet.com

Reply from WW:

The safety shaft and the hybrid studs both have additional threaded length, so prior to installing the hub, they can be trimmed down. Two guys I can readily think of, Pat Panzera and Mark Jones, have chosen to put a small spacer in here, but I would much prefer, and it is much simpler, if rear start and hand prop motors just mount my prop hub flush against the crankshaft.

Date: 5/9/03 Friends, We were just about caught up with Sun 'N Fun when we had to take several days off due to the passing of the patriarch of Grace Ellen's family on her mother's side. Charles Hayek was 93 when he died. Grace Ellen was his only grandchild. We will be back answering questions Tuesday. We appreciate your patience and understanding. Thank you.

Subj: Greetings from Brazil

Date: 5/8/03 Greetings from the Brazilian homebuilders! I'm building a kind-of KR, probably monoplace, and I happened to find a Corvair engine in apparently very good shape, mid life, good compression, runs smoothly, etc. Not a rare finding considering that in the sixties, the majority of cars here were USA-made. Two questions, if you please: 1) Sell me, please, your Conversion Manual. The best way for me to pay you is via credit card, will you take that? And the price for sending abroad. 2) As this engine looks so well preserved, I'm thinking of, in first instance, installing and flying it temporarily with a minimal conversion, i.e., changing oil radiator, carb, top and front plates, manifold, exhaust, etc. (what else?) and installing your prop hub. Then I'd test and fly it until I think it's safe. Is it possible, or should I open the engine in the first place? I know this question will be answered as I read your Manual, but your opinion will enlighten me anyway. Thank you so much. Congratulations for the beautiful service pro-builders!

Tadeu Passarelli, KR, Brazil, tpassarelli@uol.com.br

Reply from WW:

Thank you for the kind words. Yes, I take credit cards. You can order almost all my products via PayPal at the FlyCorvair.Com Online Catalog. Please also click on the $15 button for International S&H.

I would not recommend flying a motor straight out of the car. The Manual will explain all the reasons why, but the overhaul cost is small compared to the risk of damaging your aircraft and yourself. The motor is very reliable when converted. Much better than when first removed from the car. By the way, one of the most popular songs in America this month is Beautiful, a tribute to the women of Brazil. There's a music video that goes with it, shot on the beaches of Rio. I do not understand where the men in your country have time for airplane building.

Subj: 701 - RV3 and the Corvair ENGINE

Date: 5/7/03 I attended the Corvair Jr. College at San Antonio and am glad to learn that Zenair is going to do the engineering on getting a little more engine weight into the 701 (saves me from getting it done). Gus and I told each other Seabee stories at the Mini College. Tell him I said hi.

I have seen you mention a couple of times that the RV3 is not a good candidate for the Corvair. I built one of the first RV3s to fly, and while I powered mine with a 160 Lyc., I have 2 friends that chose 0-200s and they both flew VERY nice. Vans early literature states "it would fly fine on even a 65 hp but I don't think that will be a popular choice." Not many new RV3s being built, but the Corvair would make an excellent engine for it.

Gotta stop buying Corvair stuff. Made a bunch of inquiries when I started looking, and engines, heads, cases and cranks keep turning up. Got enough for half dozen engines I guess.

The Corvair Club is the way to get an engine. Nearly every chapter has members that have more engines than they need .

John Bolding, Texas, JNBOLDING1@mail.ev1.net

Reply from WW:

Good to hear from you. I told Gus you said hello. We both had a good time on that trip. A lot of serious builders in Texas.

You have discovered what I tell people all the time is the truth: The engines are truly cheap and plentiful.

Your experience on RV3s is very close to what other guys have shared with me, that the RV3 can be built as a light, efficient airframe. Three or four guys are working on them along with Corvair conversions, with the understanding that the plane would have to be built light and it will be smooth and efficient, but not in the same league as a 150hp RV3 (it won't be in the same price league either).

I've noticed over the years that the average empty weights of most examples of the same design appear to be creeping up. If the weight penalty is not bad enough, it's usually a large increase in complexity that goes with it when people turn good sport planes into mediocre IFR platforms. Let's hope the pendulum swings back the other way soon.

Subj: Exhaust stubs and clamps

Date: 5/6/03 I noticed on your Online Catolog you have listed exhaust stubs. Just so I'm clear, they are the stubs that attach to the cylinder heads?? I had a few that were bent and a couple others that I could not remove the gasket material for anything. If they are what I think they are I would like to order a set.

David Vegh, Chandler, Ariz.

Reply from WW:

Good to hear from you. The parts we offer bolt on to the stock steel stack. If you need some stock stacks, I have some good ones I removed from other heads. Let me know how many you need. The cost is $10 each. With a good set of stock steel stubs in place, the pieces we sell give you the beginning of the exhaust system after this.

Subj: Early Heads

Date: 5/5/03 Can early heads be modified to work with a later crank? According to my book, they are 8.3:1 CR. Can they be flycut?

Mark, matee@trib.com

Reply from WW:

It's best not to modify the early heads. When you increase the displacement, given the same chamber volume, the compression ratio will increase and your 8.3 will look a lot more like 10:1.

Subj: Head question

Date: 5/4/03 Here is my "Is my engine ruined" question: I certainly don't know much about the engines, and suspect the guy I snagged it from knew litte more than I, so rather than explain what I thought I bought (other than it was a turbo), these are the numbers:

It does have the 8409 Crank, but the case and head numbers don't seem to match anything in your book. The heads are 3819904. The case is TII05YR (with the caveat that the 'T's and 'I's may be flakey because it's hard to tell the difference).

Hoppy, hoppy@houston.rr.com

Reply from WW:

The motor you've run across is a 1964 150hp turbo engine. This would have been installed in the high performance Spyder. Everything you've got is usable, with the exception of the cylinder heads. You need to find a set of 1964 heads. The acceptable numbers would be 3856626, 3839887, 3839886, 3819876, 3856632 or 3856631. 1964 was a big production year - more than 250,000 engines were made that year. You should have no trouble finding a pair of the above heads. A car collector will certainly trade you, as the 150 heads are worth at least three times what a set of 110s are worth.

Subj: New Case Assembly Video

Date: 5/3/03 I received the parts last night, and viewed the video today. It was wonderful. When are you coming out with the next one?????????

I do have one question? In the video, when you mounted the two case halves, you didn't use any form-a-gasket or anything. Is that correct, you don't put anything on either side of the case when mating the case halves? Thanks.

Fish Fischer, Dragonfly, Warrenton, Ore., fishhole@pacifier.com

Reply from WW:

Thank you for the compliment on the video. All of our videos are directed, produced and edited by good friend Merrill Isaacson, aka Sky Manta. In addition to being a video wiz, his Corvair motor was on display and run at Sun 'N Fun this year. Making good videos is a snap when you have pros like Merrill doing the hard work. Merrill is currently editing Engine Assembly Video Part II, and we're shooting Part III next Saturday. This trio will cover the whole engine assembly process. Part I is available for $29 in the U.S. (add $15 for international S&H, including Canada) by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the FlyCorvair.com Online Catalog.

Nothing goes between the two case halves. Between the oil pan, the end covers and the top cover there's only 1/4" of potential leak area. Experience has shown that oil will not come out of this area. Every time someone tries to put something between the two case halves, it effects the clearance on the bearings and allows the case to move. Assemble it bare, just as I did in the video.

Subj: Rans S6S Coyote II

Date: 5/2/03 We're building a Rans S6S Coyote II kitplane. We come to the point of selecting a suitable engine, and the Corvair looks like a great option. We are good at following step-by-step instructions, but not good at welding and building parts for an engine. So we're looking for a complete firewall forward package, ready to bolt on. Can you supply a Corvair engine and the mount materials to fit it onto our S6S? As weight is important, we'd probably need some (or all) of the light-weight options. Electric starter is the only option we'd like to add weight from, and probably the dual ignition too. Can you quote us a price for that? We already own a 3-blade Warp drive ground adjustable prop, beyond that we're open to all suggestions. Best regards,

Rob, r.turk@chello.nl

Reply from WW:

Subj: Questions, Questions, Questions!!

Date: 5/1/03 Bob Tolliver here from Butler, Tenn., Manual number 5203. First let me get you up to date. Yesterday, for the first time since I got my Corvair engine, I had some time to start a tear down. I just got my shop manual and finally had a break from college during Easter so I could do something fun. It was nice to be able to get my hands dirty again! My engine looks fair so far. The car had been in a flood, but the water never got over the top of the engine, no water got inside, just moisture. I pulled the top plate off and the cast iron crank looked fuzzy! It had so much light powdery surface rust on it. It seems to be light with no pitting. I have yet to get the heads off or the crank out. The case had enough oil in it to register on the dipstick. At first glance the oil pump even looks good. I will know more after I clean it all up.

I am having trouble getting the distributor housing out. I have it loose and it will turn, very stiffly, but won't come out. Is there a trick or something to this?

I have overhauled many engines and have had a lot of luck by just using a cylinder hone and re-ringing the pistons as long as the cylinder is good and round. I have read that this won't work on a Corvair engine. Why not? I understand if the jug needs bored out to make it round again, but if it just needs slight honing why do you need new pistons? I understand there is a problem with possible detonation blowing a hole in a stock piston, but beyond that, why?

The Roger Mann, RagWing Stork, RW20 is a side-by-side STOL aircraft about the size of a Super Cub and calls for a rather huge 72" diameter prop. I want the plane to have maximum STOL abilities, top speed is not really that important (the Vne for the airframe is 120mph), so what type of propeller do you suggest? Pitch and Dia and where should I get it from?

On the same note, I have heard mention of building a left hand rotation Corvair engine. Since I need such a weird prop size, would this be the way to go for me?

In your book you make mention of using new rod nuts. Taking into consideration the low rpm that this engine will be seeing, and the fact that you say a Corvair engine has never thrown a rod, and as long as the nuts are in good condition, why not reuse them?

I will probably use an aftermarket oil cooler from Summit because mine does not have enough plates. Any advice on this?

I may have missed it in your book, but why not use the stock carbs that came with the engine? They could be easily relocated underneath the engine on some sort of plenum box and both could be incorporated like a six pack on the old Dodges. Or for that sake even be moved to behind the motor, if the cowl was big enough.

I have been trying to find a flex plate from a Nissan Sentra, but my auto dealer needs a year. What years do I need to look at? Will the flex plate off of a Chevy Metro work? (I have one I am parting out.)

Could you E-mail me an updated parts list? If too much trouble, I can probably find it on your Web site.

Will you have a new Manual coming out any time soon? If so, it would be helpful if you included an index in the back. Also, since you have such experience rebuilding Corvair engines, why not make a manual complete with all the rebuild information in one so there would be no need to obtain an overhaul manual. I tried to get one from every library I could think of and called all the auto parts houses, even went to the Chevy dealer. I had to break down and buy one form Clark's. $20 some dollars to get 30 some pages of information. You could put together a more informative rebuild manual and increase the price of your conversion Manual. It would be much more convenient for us builders. My bedroom has one and a half bookshelves filled with aircraft books already! Now I have about six on the Corvair including catalogs. Just a thought for you to ponder.

I know I have a lot of questions here, but I would be ever so grateful for your time and answers

Bob Tolliver, RW20, Butler, Tennessee, Wolfdragon62@wmconnect.com

Reply from WW:

Nice to hear you're getting your hands dirty. Some very nice aircraft conversions have been built from motors that at first glance appear to be horrendously filthy and dirty. Careful inspection and measurement should reveal that most of the parts in your engine will be useful in the rebuild.

A quick correction: all Corvair cranks are forged steel. They are not cast iron. I have seen many cranks that have an external surface coating of rust clean up very nicely. This is from having a tremendous amount of moisture in the crank case over a long period of time. Don't be too concerned about the appearance. Let the clean up and inspection make the decision.

Soak the distributor in penetrating oil. You can get better access by taking the oil pump out and spraying it up the drive shaft hole.

My Conversion Manual covers pistons in detail, but I do not like using stock, cast pistons in a flight motor, especially 35-year-old ones. A number of Corvair engines which have had cheap rebuilds for cars fail the top ring groove of the piston because honing does not adequately remove the wear ridge in the cylinder.

The only prop you should consider for this airframe is a two-blade, ground adjustable Warp Drive. Contrary to popular old wives' tales, a 72" diameter Warp Drive can be used at rpm up to 3,000. This is a perfect match for the direct drive Corvair. I've tested this personally at my own shop, and we had one of these props on display and running during Corvair College #4 at Sun 'N Fun 2003 this year. I sell these props for $580 plus S&H. They have an excellent track record. All Corvair motors are left hand rotation. The option is to build a right-hand rotation Corvair motor, but I don't recommend it. Virtually all the Corvairs flying have been standard Corvair rotation (left-hand rotation).

The Manual covers this also, but always use new rod bolts. They're cheap insurance. You never know who overtorqued them before you. Although broken rod bolts are unknown in Corvairs, why try and find out what you can get away with, as opposed to doing what we know is better.

The easiest thing to do on the cooler is spend $25 with Clark's Corvairs and buy a 12-plate cooler. Most aftermarket coolers are designed to fit in front of car radiators and are the wrong shape for aircraft cowlings.

Yes, I mentioned in the Manual that Corvair carbs have been flown, but I also specify a number of reasons I recommend updraft aircraft carburetors.

The ring gear from the 1987 Nissan Sentra 120cid motor is the one I've previously used. I've recently shifted to the Ford Taurus ring gear, and the complete update is covered in my newsletter, The Corvair Flyer. This is available, as well as your requested list of all parts and now videos, at the flycorvair.com Online Catalog.

As for your comments on manuals, let me say this. The GM overhaul manual is an incredibly good book for $20. It is copyrighted information, and is not available for inclusion in my Conversion Manual. The amount of time you spent searching libraries was worth far more than the $20 something you spent. I have worked very hard to hold the cost of my Manual down, and people respect this. It takes an efficient operation like the one that I run to sell hundreds of Manuals a year for the modest price I ask and still maintain the customer service standards which allow me to personally answer letters, no matter how long they are, from individual Manual owners. Do not fret over having more books on your shelves. I own a houseful of technical manuals, and I have come to notice that the people who build the most airworthy airplanes tend to have thick bookshelves. People reluctant to gather and use information tend to have dormant projects with dozens of glaring mistakes that could have been avoided had they indulged themselves with a few of the commonly available books. Isn't this the philosophy that led you to college in the first place?

Subj: Eagerly awaiting new Conversion Manual

Date: 4/30/03

Nice work with spreading your knowledge on the Corvair conversions. I'm pretty handy, but I'm not a motor head by any means. I'm trying to learn all I can to use the Corvair engine. Thanks for including the copy of the newsletter. If I can learn from it, I'll order it. I really want to learn about what carb to use, and the differences between them (Corvair carbs, updraft, downdraft, sidedraft, throat sizes, gas tank location for head pressure....all that stuff). I need to learn when to use a starter and when not to, and what's up with the blower on top; some people use it, others don't....

I hope I can learn these things with the help of people like you and your newsletter. I am also interested in attending your Corvair College one of these years. I'd like to know if I need to bring all the new parts with me, or can we buy them down there.....

p.s. I wonder how long my engine mount should be. Do I need to build and cover the whole plane before I know how long to make it?

Thanks again.

John Egan, Litchfield, Ct., jegan@kcc.com

Reply from WW:

The Manual you ordered will answer all of your questions asked here, but let me take the opportunity to answer them here quickly so everyone else can learn as well.

You mention not being a motorhead. Don't worry about this. The vast majority of Manual owners have never rebuilt an engine before. This is not a handicap. In fact, it means you're much more likely to follow the plans and do careful work.

The Manual, available in the U.S. for $59USD by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15USD for international S&H, including CANADA), covers all types of carburetors and fuel systems and the airframes to which they are applicable. In short, the Corvair will run on a multitude of carburetors. Most of the hours with the engine have been logged on a Stromberg NAS3 (from the C-85 Continental). Today, the two most popular carb choices are the MA3SPA (O-200) and the Monnett AeroCarb.

As for electric start, I cover all the issues on front and rear starters in the Manual. I have built and flown both in several versions. I highly recommend electric start.

Corvairs are commonly used and were the specified engine for all Pietenpol Air Campers after 1966. Bernie's conversion was a hand propped engine which retained the stock blower fan. Many engines were built exactly like this for Pietenpols, and some have logged well over 1,000 hours. The only case where I would use a blower fan/hand prop motor would be in building an exact replica of one of Bernie's planes. My own Pietenpol had electric start and no blower fan.

I offer engine mount kits and complete mounts for a number of different popular airframes. Some aircraft, like a KR2, do not require you to complete the airframe before building the mount. I have a large database of completed airframe weight and balance reports which went into the design of my mount. Conversely, if you were building an original design, you might want to leave the motor mount for last.

Subj: Prop L or R

Date: 4/29/03 Ordered the new Manual and the engine should be ready this year. My question is, in a pusher configuration, will I be needing a left or right hand prop? Plan on getting an in-flight adjustable. Do you think Ivoprop is my best bet?

Know you're busy, love the magazine articles. Thanks for your time.

T-lll by the way, wanted beta to back off the beaches down here in S. Louisiana.

R. Giroir, T-III, La., fasteel2000@msn.com

Reply from WW:

Good to hear from you. Yes, if you use the engine as a pusher, you need a specific pusher prop for it. Under no circumstances should anyone use an Ivoprop on a Corvair motor. I used to be an Ivo dealer, I know their products well, and there is no Ivoprop that is structurally sound on a direct drive 4-stroke motor. There may be someone who debates this, but keep in mind, it's their words and your life. Most people survive their first engine failure in an airplane. On the other hand, losing a propeller blade in flight has much grimmer survival statistics. Beyond the fact that these props do not have any type of performance advantage on the Corvair, no one should accept the unnecessary risk of operating an Ivoprop on a Corvair.

I understand the attraction of in-flight adjustable props, and I continuously investigate new ones coming to the market for their applicability to Corvair engines. The only prop which I believe is light enough, has an advanced blade design, a simple in-flight mechanism, and comes from a reliable, stable company, is the Hoffman. Hoffman props are made in Germany, and are frequently seen on certified motorgliders.

Subj: Finding an engine.

Date: 4/28/03 Hi William, my name is Keith Smith and I'm looking for an engine to power a KR2S that I hope to start building within the next 2 years. My question is: What types of cars did GM put these Corvair engines into? If I were to look for one in the paper, what would I need to look for?

Keith Smith, Ssmithsk3@aol.com

Reply from WW:

From your comments, I assume you're a member of Generation X. I myself am one of the last of the Baby Boomers and I can remember when a lot of people still drove Corvairs as a daily driver. The economics of the engine make it attractive to a lot of guys getting ready to make their first mark in aviation. You are in good company.

The Corvair was a separate model of cars built by GM that were sold under the Chevy banner. Inside, they are truly Chevrolets in the sense that they were designed, built and sold through the Chevrolet division. If you were to run an ad in the paper, you would be looking for a 1964-69 110 or 95hp Corvair motor. These would have been installed in Corvair vans, pickup trucks, 2-doors, 4-doors and convertibles. This is just the same as the way GM made 2-door, 4-door and convertible Chevelles.

My Conversion Manual details all the information you'll need for an effective engine search. It is available in the U.S. for $59USD by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15USD for international S&H, including CANADA).

A couple of years ago, I drove from Florida to New Jersey and back in a friend's 1963 Corvair Coupe. The car was lowered, had wide tires on it and was painted bright red. It was different looking, even for a Corvair. I stopped in a Georgia gas station, and an 18-year-old attendant wearing a Chevrolet hat was a little puzzled as to why I was putting gas in the front end of the car. He was very curious and I showed him the engine in the back. Although he was very interested, the car must have seemed like some kind of strange import to him. He asked me, "Who made this car?" Noticing his hat, I thought he would enjoy hearing that this innovative product was made by his very own beloved Chevrolet. When I told him this, he gave me a look like I was the worst, lying, blasphemous, Commie bastard he'd ever met in his entire life. I showed him the Chevy emblems on everything, but he still wasn't convinced.

Subj: Combustion Chambers

Date: 4/27/03 The Conversion Manual that I just got states "that the heads from the low compression smog 110hp and 95hp engines are NOT RECOMMENDED."

I've not listened to Rush in many years, but he used to have a saying, "words mean things." I believe that you were stating to not use "low compression smog," be they 110 or 95, not that all 95s are bad. On Page 18 of the new Manual, you speak highly of the 95 engine. You go on to say that the 95 SMOG head has no quench areas, whereas the head in the photo in question clearly has quench. Please explain. Thank you.

Sam Sayer

Reply from WW:

You read this correctly. What I'm against are heads that do not have a quench area. By far, the vast majority of 95s do have a quench area. I have built and flown numerous engines with these heads, and they work very well. Ditto for the 110 heads.

The heads I do not like are the open chamber, no quench castings. These include the smog engines and the 180 turbo heads. These heads are rarer than people think. My guess is that they were something like 5 percent of the 110/95 production. But, I do want people to be alert for this. I personally have flown time on the wrong heads, and can assure you that they will fly and work, but they reduce your resistance to detonation. For the small effort of getting the correct heads, you can be confident of building a better engine. The photo in the Conversion Manual illustrates the sort of heads you should be looking for. For all those who do not have the latest version of the Conversion Manual, it is available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15USD for international S&H, including CANADA).

Subj: Early Motor

Date: 4/26/03 My son, Chris McAtee, and I are building a TriQ and plan on powering it with a Corvair. Chris ordered your Manual and then headed off to college to let me continue working. After letting the project sit for a couple of years and waffling on the engine choice, one of my flight students, Dave Caylor, purchased a Piet with a Corvair. He showed it to a prof of engineering at our local college who then wrote you a letter that you posted on your site. Dinking around one day, I looked up your site and saw his letter. Since he mentioned that he had several running Vairs and being in the same town and having little luck finding an engine core, I e-mailed him. He promplty responded that he had just junked out a running '64 and had the engine in his way at the moment. To make a long story short, I headed out with your Manual in hand. After checking the suffix number on the case (engine complete with all fan shrouds on) and seeing the '64 sitting there (it is a "YN" number), I purchased the engine after being assured that the engine was probably the original. After teardown, the head numbers (3813516) match those of an early 102 horse and it has the wrong number on the crank. It is probably a 145 (I'll mic the cylinders on Saturday).

Question: Is anything on this engine useable? It is in VERY good condition. Are the cases for the early YN engines the same as the 64 YN cases? If I get the stronger rods from the newer engines, will the OT-10 cam fit? Boils down to......did I spend $40.00 badly?

Mark McAtee, TriQ, Casper, Wyoming, matee@trib.com

Reply from WW:

You have the bad luck to have gotten a 1961-63 engine from the 1964 car. The good news is there is certainly $40 worth of parts on the engine. The main difference between your motor and a long stroke case is a slight relieving to allow for a longer stroke crank. An hour's work with a die grinder makes a short stroke case capable of handling an 8409 crank. It is not difficult work to do. The OT-10 cam will fit right in the case. All the other stuff will bolt right to it. Chances are you'll come across a 1964-69 motor for less money than it would take to buy the crank, rods and heads separately. Either way, your $40 was a very inexpensive starting point. I don't believe anyone else in America spent $40 last week and got as many aircraft engine parts as you did.

If anyone knows of any engine leads in the Casper, Wyoming, area, please e-mail Mark directly.

Subj: Corvair Fold-A-Plane

Date: 4/25/03 Friends, We ran a short story on Steve Rahm's new single place project in the last Corvar Flyer newsletter, Spring 2003. If you'd like to take a look at a professionally designed single seat airplane for Corvair power, here's a link to Steve's site: Corvair Personal Cruiser.

William

Subj: UAVs

Date: 4/24/03 I'm doing a general survey for a large UAV company into the usability of various engines. Where can I find more technical information (Lubrication, Ignition, Weight, displacement, BSHP, FF, BSFC, etc) about Corvair engines? The Web site does not seem to list this info. TIA, Regards,

Geraldo van den Heuij, The Netherlands

Reply from WW:

Although I know all the data you need on the Corvair motor, UAVs (Unmanned Aerial Vehicles) really only have two applications in practice: government surveillance of civilians and military applications. I am in no way interested in assisting anybody with the former and would only assist my own countrymen with the latter, but I am quite sure that the U.S. military has much better stuff than could ever be operated by Corvair motors. Hope you take this the right way. I'm sure somebody in your home country would respond exactly the same way if the roles were reversed.

Subj: Thermal Efficiency

Date: 4/23/03 G'day. I'm an Australian living in Melbourne who has a great love of aircraft and who regulary reads the information on your Web site.

I note that the specs on your Web site show that the Corvair, particularly the O-190, is an oversquare design (larger bore than stroke) and that you state that the engine's stroke of less than 3 inches contributes to its smoothness. I've been wondering if an oversquare design has a higher thermal efficiency than an engine with a lower bore/stroke ratio. Do you know if this is generally the case? To me it would seem to be for reasons such as: the BMEP remaining higher for a greater proportion of the engine's stroke, mechanical losses would be less because piston speed as a function of crankshaft speed would be lower, and because the piston area to circumfrence ratio would be higher leading to lower leakage of BMEP past the compression rings.

If you can would you be able to confirm these ideas or put me straight if incorrect. Any assistance will be greatly appreciated. Regards,

Andrew Patmore, Melbourne, Australia, patmore@tpg.com.au

Reply from WW:

Your questions indicate that you have an engineer's perspective on engines. Very rarely do we get such in depth technical questions. While there are many things in life I do not know much about, I can honestly say to you I have an unusually good background in the fundamentals of physics, chemistry and thermo. This combined with my practical observation and many, many years of reading and learning from people far smarter than myself have given me a good background from which to discuss these things.

The main issue that you need to look at in motors is not bore and stroke, but rather the stroke to rod length ratio. Most automotive engines in America have a 1.65 to 1.75 ratio. When this ratio gets better, like toward 2:1, the piston has dramatically more dwell time at TDC. This is where really thermally efficient engines start. The down side is the piston is subjected to more brutal accelerations and decelerations. Many people look at average piston speed, but this is a meaningless number. The real issue is how steep the acceleration curve is. This is the real limit. The Corvair's rod length is about 4 3/4". Its rod ratio is 1.62:1, average for a car engine. In production engines, you'll notice diesel engines are the opposite extreme.

You talk about a number of variables. If we were to change just one on the motor, you could easily discuss or evaluate its effect. Engines with a bore and stroke combination that produces the least surface area tend to lose less heat. This tends to favor square engines. Most people mistakenly believe that given engines of equal displacement, long stroke motors somehow produce more power, but testing reveals this is rarely so. Probably the reason most people believe this is ram tuning leading to higher volumetric efficiency requires less homework for the designer on a long stroke engine.

Subj: Learning what's not in the book

Date: 4/22/03 Thank you again for your reply to the Florida Pietenpol for Sale.

I am an ag pilot with well over 1000 hours. I have always followed the "standard" carb heat procedures without any problems. But I did not really understand the mechanics of what was taking place, because it was never explained. This rather makes me wonder if my instructors knew. Your article regarding carb icing is a real eye opener and will go with me and will be taught in all future flights. That is one of the many reasons I wish to be a Sport Pilot Instructor. An old ag pilot told me one time, "Son, learn what is not in the Book if you want to stay alive." Have a great day,

Benny Clark Sr., Pietenpol, Texas, texaswings@cox-internet.com

Reply from WW:

Thank you for your complimentary comments. I believe your observation on the average instructor's understanding of carb icing is quite correct. While I was fortunate enough to have a flight instructor who understood technical issues like carb ice, I feel that there are probably many instructors who may be good pilots but don't really understand physics and chemistry. This is why Grace Ellen took the time to write the article, posted on my flycorvair.com Web site at Carb Ice. I think your instructor's thought on learning what's not in the book is very good advice. One of Grace's flight instructors always said, "Your pilot's license is a license to learn, not the end of your education." ... Solid advice.

Subj: Zenith 701

Date: 4/21/03 I just purchased your Manual mostly because of curiosity, but I'll think of it more as an investment. I plan to put a Corvair on a STOL 701 (Version 4 - 1,100 lbs. gross) mainly because I see a lot of them with the SOOB power (pretty heavy when it is all added up).

I know I am going into uncharted territory - but this IS experimental aviation isn't it? Look forward to the delivery of the Manual.

Martin Bima, Zenith STOL 701, Winnipeg, Canada, mbima@hydro.mb.ca

Reply from WW:

This year at Sun 'N Fun, Zenith announced that engines the weight of an O-200, EA-81 or a Corvair are acceptable on a 701. They may have some firewall beef-up in mind, but they told a number of 701 builders that the Corvair would be acceptable. Keep in mind when dealing with Zenith that the only time they use the term "approved" with an engine is when they have personal flight experience with it. Until we're at that point, I just tell people the Corvair is within Zenith's weight and horsepower requirements. In the future, I think this will be a very popular engine combination. Previously, Zenair would tell us they wanted no more than 200lbs. firewall forward and I must have had 200 people ask me about this in light of seeing O-200s and Subarus on the 701.

Subj: Florida Pietenpol for Sale

Date: 4/20/03 I am really confused. I am considering purchasing a Pietenpol located in Florida. The owner I am convinced is an honest person and has suggested that he would not fly the Pietenpol from Florida to Texas. He is not comfortable with the engine since some of his friends had an engine failure from carburetor ice and almost got killed. From the information on your home page, maybe pre-judging from others' bad experience is not the best thing, although the engine is direct drive. It has a static run up of 2600 to 2700 with a propeller designed to accomplish this RPM. And I am told this propeller and RPM will produce some 100 to 110 HP. Would you be kind enough to council me in my dilemma as to what to do??? Have a great Day,

Benny J Clark Sr., Pietenpol, Texas, texaswings@cox-internet.com

Reply from WW:

I suspect you have been dealing with a man named Joseph Vince, who also calls himself "The Reverend Joe." Unfortunately, he is not an honest person. Nor is he a friend or associate of mine, and he did not convert his Corvair according to my Conversion Manual. I have personally inspected his aircraft, and can assure you that it has numerous structural deviations from B.H. Pietenpol's plans. I have seen the aircraft advertised on the Internet, and would only wish that it not bring tragedy into someone's life. Joseph Vince's engine was built out of junk parts with a very low level of knowledge, craftsmanship and care. The fact the engine failed on its first flight came as no surprise to people who had seen the aircraft in person. The real surprise was that Joseph, who purports to be a man of God, would talk someone else into flying the plane for him. I bear no malice against this person, but I cannot understand his actions, and I know aviation, the passion of my life, does not need another black eye.

Under no circumstances should anyone purchase either Vince's "Pietenpol" or his "engine." Neither are airworthy for a multitude of reasons.

I did get seriously injured while riding in my Pietenpol as a passenger. After the engine went out due to carburetor ice, the pilot spun the plane in from about 80'. The full story is on www.flycorvair.com at the page titled Carb Ice. Following the number one rule of FLY THE PLANE, would have prevented this, as would have checking the weather, pulling on the carb heat knob which was located at only the pilot's controls, installing a carb heat knob in the front cockpit, being more selective about who I let fly the plane, etc. As long as you are a diligent pilot, this kind of accident will never happen to you.

My standard suggestion is convert the engine yourself according to my Conversion Manual, build the plane yourself according to Bernie Pietenpol's plans, and learn to fly for yourself with a competent instructor. You will enjoy both peace of mind and pride in workmanship if you trust in and rely upon yourself, and ask questions without hesitation when you need a little extra help.

Subj: Corvair Fuel Pump

Date: 4/19/03 I visited your Corvair presentation at Sun 'N Fun. Do you know that there is an AD note on all Franklin engines using the diaphragm type fuel pump? This happens to be the same fuel pump used on the Corvair motors. I don't know what the replacment would be as it didn't specify in the AD. I haven't had any trouble with the one in my Corvair. What's your take on this.?

Bob ODell, Panacea, Fla., Lledobob@aol.com

Reply from WW:

You are quite correct that certified Franklin motors were delivered from the factory with Corvair fuel pumps. Several years ago, there was a fatal accident in Texas in a Franklin powered Swift that utilized this fuel pump (I am pretty sure there has never been a fatal accident in a Corvair powered aircraft). You can read the accident report on the Web at www.faa.gov, and there are a number of other factors involved besides the fuel pump. Franklin engines are made in Poland, and the American fuel pump manufacturer may have been a more tepmting litigation target. As a result of a lot of litigation, etc., there is now an AD. So that everyone understands, ADs only apply to certified aircraft. My personal experience with Corvair fuel pumps is that they are reliable and when they quit, they give fair warning. If they have been less than reliable in Franklin engines, it probably has something to do with that installation or perhaps their overworking it to feed a 220hp engine. I would not be very concerned about using it in its stock Corvair application.

Subj: Parts

Date: 4/18/03 We’re finally getting around to building our engine and need a few parts. The guy we bought the engine from did a great job except that he spent a lot of time putting a magneto on it. I’m not sure why he didn’t get the performance out of it that he expected:) We need the rear housing, oil filter adapter plate, by-pass valves and one of your dual ignition distributors. What all comes with the distributor - cap, rotor, re-curving? Know anyone who wants a magneto for their Corvair engine?

I have to warn you, dad met you about a year ago in North West Florida at a small EAA fly-in. He says that he has several questions for you??? Should be interesting.

I’m building a Vision and stopped by in November to see Steve. We walked all the way over to your place but you were out, sorry I missed you. Thanks,

Brian, Vision, brianyoung@charter.net

Reply from WW:

Sorry we missed you. We spend about 100 days a year on the road. If anyone is planning on a visit, please call in advance. We've had hundreds of visitors to the hangar over the years, and you're always welcome.

Undoubtedly we met your Dad at the Quincy Fly-In near Tallahassee, Fla. We had a great time there, and there were a lot of very mechanically clever guys, typical of many rural areas in America. Certainly e-mail any questions your father has. Since you have my Manual, you know my experience and opinion with magnetos (great for certified motors, not appropriate for Corvairs). Please note that my dual ignition distributors are now completely re-manufactured in house and contain everything from the bottom of the shaft to the top of the cap. You need only send us your old core and a check for $219 payable to William Wynne, 210-11 Cessna Blvd., Port Orange, FL 32128 (add $15 for international S&H, including CANADA). These are also available by credit card via PayPal at the Online Catalog.

Subj: Corvair in Merlin

Date: 4/17/03 I'm looking at purchasing a Merlin kit (without Rotax) & have been eyeballing the Corvair. Do you know of anyone who has used the Corvair in a Merlin?

Doug Baird, DBaird@barroncollier.com

Reply from WW:

I do not know of anybody who has used a Corvair in a Merlin. The Merlin is a fairly efficient airframe in its class, and reported to be a very sturdy design. The Corvair has very successfully powered a number of aircraft in the Merlin-size category that were substantially less efficient. If you can get a report from somebody flying a Merlin on an O-200, this would give you a good indication of its performance with a Corvair.

Subj: Engine for Zodiac 601HDS

Date: 4/16/03 I have finished most of the airframe on my Zodiac and am looking for an engine. I bought a Subaru EA81 at a junkyard, but after looking at the cost of a PSRU and other expenses to get ready, I am about to change my mind. I am interested in a Corvair and thought I would check the availability of one in my area (Western Kentucky) but wanted to ask your opinion on which engine would be best suited for the 601, a 164 or 190? If I go this route I'm sure I will be buying your Manual and some parts. Thanks for your help.

Mark Sandidge, Zodiac, Madisonville, Ky., MSandidge@PeabodyEnergy.com

Reply from WW:

Thank you for going ahead and buying the Manual. While your questions will be answered in the Manual, available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA), let me share the answers with other readers of the Web site. While I am emotionally biased toward American products like the Corvair, the factual numbers bear out that the Corvair, even the standard 164cid power plant, will be a better power plant for your 601 than the EA-81, even with an expensive PSRU. My opinion on this is based on replacing flying Subarus with Corvair engines in two KRs and a Stits Skycoupe last year. The KRs were much lighter with direct drive Corvairs, and had better performance with far more conservative use of the engine. Notably, each of these engines was built for less money than the PSRU cost for their respective EA-81s. Corvairs can be found in every part of America. Most guys spend less than a week looking for one after they decide to build.

I'm working with a number of 601 builders to produce drawings and parts to make your engine installation simpler. This is high priority for me, and you can expect to see things like the motor mount soon.

The direct drive, air cooled simplicity of the Corvair is much more complementary to the 601, which has the same values of simplicity and reliability.

Subj: Piet Corvair

Date: 4/15/03 I am just starting a Piet (ribs built, moving on), and I am interested in a Corvair for power. When is the next "Corvair College" scheduled? And are previous "College" pictures, tapes or whatever available?

Daniel Bailey, Pietenpol, EAA 96269, Chapter 868, Olathe, Kansas, dbceltic@micoks.net

Reply from WW:

We just had Corvair College #4 at Sun 'N Fun 2003. At this College, I introduced the first tape in my engine building series. It is available for $29USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA). The second tape in the series is being edited now, and the third will be done by Oshkosh. While I'll be speaking at Brodhead and Oshkosh this summer, I have no firm plans to hold a College at either location. I have traveled to Kansas several times to promote the Corvair motor. In the past, we've attended the Tandem Wing Fly-In in Ottawa, Kansas, and demo pilot Arnold Holmes operated my Pietenpol out of Gardner, Kansas, for a month in the Fall of 2000. Perhaps you remember seeing it.

The Corvair and the Pietenpol are a natural combination. Remember, it was the specified choice of Bernie Pietenpol.

Subj: Corvair forums at Oshkosh

Date: 4/14/03 I had met you at Sun 'N Fun but hadn't attended your rebuild sessions. I'm wondering if you're going to be at Oshkosh this year. Please let me know. THANKS.

John, jcl64@a-znet.com

Reply from WW:

I will be giving forums at Oshkosh 2003 for my second year in a row. Check back at the AirVenture 2003 Forums Page and the News from the Corvair Authority Page on flycorvair.com for the schedule as it becomes available.

Subj: WOT Fuel Flow

Date: 4/13/03 Have you tested a Corvair to run all day wide open, 3200RPMs? What is the fuel flow on the big O-190 WOT? Has anyone ever put fuel injection on these? It seems like a good idea fuel injected since the need for a fuel pump on my plane is already there.

Justin, jmw116@socal.rr.com

Reply from WW:

The longest length of time I've operated a Corvair motor at WOT was 2 1/2 hours at 4500rpm. After a 5 minute break to refuel, it did another two hours at the same output. The Corvair motor ran at more than 3200rpm at highway speed in the original car. The engine is not bothered by any rpm that you would find useful in a direct drive engine. Fuel flow at any power setting is directly related to the amount of power developed. A Corvair motor, like almost all others, burns .5 pounds of fuel per horsepower per hour. Thus, 100hp continuous output would be 50lbs. of fuel, which is 8.3 gallons per hour. Please note that very few aircraft engines, even certified ones, are operated at WOT all day long.

I have done work on some of the most sophisticated aircraft in sport aviation. I have experience with the fuel injection systems on these engines and it is my opinion from experience that virtually all homebuilders would be better served with a carburetor. Fuel injection is covered in several pages in my Conversion Manual, available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA). In short, the claims of great fuel savings will never materialize, and the complicated electronics, their high power consumption, single point failure modes, 35psi fuel systems, etc. are an entirely different category of aviation risk management. If you really want to go flying, build what experience has shown to work and let craftsmanship be your personal mark on your aircraft.

Subj: Getting Started - EAA Experimenter March 2003

Date: 4/12/03 I just wanted to thank you for writing the article, "Making the Decision to Build Isn't Easy or Rational," in the March 2003 issue of EAA's Experimenter magazine.

For several years I have been "struggling" with all the reasons why I wanted to build an aircraft, and also, with equally valid reasons why not to. I, too, had been trying to "rationalize" my feelings towards this project and getting nowhere. Not being able to verbalize my feelings to my family and friends did nothing to help my cause. After reading your article, I immediately understood that my reasons for building were more deep-seated than I had originally thought.

I have just returned from Sun 'N Fun. There, while speaking to homebuilders about their projects, I couldn't help but notice similarities in their expressions and passion in their voices when they spoke about the "building process." I will assume, since the results of their labor was sitting right in front of us, they used this passion to see them through to completion. Another common thread was the pride they felt when they took flight in their labor of love. Frequently, they would punctuate their sentences with phrases like, " . . . I've never regretted it . . .," or ". . . this is my lifetime achievement . . . ".

Your article helped me understand that my passion to build is tied more to a combination of my love of flying and my need for a creativity outlet rather than simply the need for an aircraft. I've removed the "no rational reason to build" entry from the "minus column" and happily added the entry "outlet for creativity" into the "plus column."

Thanks again for a great article. Best regards,

Stuart Heitshusen, Schenectady, N.Y.

Reply from WW:

Thank you very much for your kind words about my column in the Experimenter. Mary Jones, the editor, asked me to write a continuing column specifically aimed at the person who is a first time builder, just like you. Her request reflects EAA HQ's emphasis on including all people in homebuilding, not just the most financially fortunate. I tried to address the most common concerns and issues which first time builders face, for I myself went through this process just like you.

Subj: Engine Block Suffixes

Date: 4/11/03 I spoke with you at Sun-N-Fun (with about a million other people!) and got your Conversion Manual. I have obtained enough parts to start building an airworthy engine BUT...my block has suffix letters RN. This is not posted in your book and I am wondering if I have a good block? Incidentally, the guy I bought the pieces from showed me a factory publication and there are a LOT of designations that aren't reflected in your Conversion Manual. It's probably not a big deal, but I rely on your experience and this one is a stumper.

Larry, lnawms@msn.com

Reply from WW:

Your RN motor is a 1965-66 140hp Powerglide equipped engine. The only parts of this engine which are not suitable for use on your conversion are the cylinder heads and the 4 degree retarded crank gear. The good news is that the crank gear can be replaced with a new one for about $85, and the cylinder heads are worth up to $300 for the pair to a car guy. The much more common 110 cylinder heads are the ones you want. They are much cheaper, and will bolt right on to your cylinders. Other than this situation, which precludes its inclusion in the Conversion Manual, your motor is an excellent core.

Subj: Carburetors

Date: 4/10/03 In your Conversion Manual, you speak of MA-3 and MA-3SPA carbs costing upwards of $500. In my search so far I have been unable to find one for even close to this price. Where have you seen such prices?

Gordon Alexander, Shakopee, Minn., gordon@curio.com

Reply from WW:

At Sun 'N Fun I saw 20 of these carburetors for sale for less than $350. The Fly Mart had a shelf of them with an average price of $300. These are very common carburetors, as they were original equipment on O-200s. $300-$350 is fair for a good working one with a metal float (MF will be stamped on the data plate). I would pay $500-$700 for an overhauled one as long as it came with a yellow tag from a repair station. I've also purchased them off eBay and Barnstormers.com.

Subj: Zenith 601XL Engine Costs

Date: 4/9/03 Am about to build a Zenith 60XL and am very seriously considering engines. I have 2 engines sitting, a 110 and a 140 hp. Are any currently flying on the 601? Could you get me in touch with the builder? Am also curious if you would be willing to supply me with cost for a conversion that I might do and give me a cost for you to build to 120 hp with electric start, 20 amp alternator, dual ignition, starter solenoid, exhaust... and let me know about engine sensors that you might think useful... I'm looking for a bullet proof and reliable engine with a long life... Thanks,

Jim, Zenith 601XL, jdankochiro@yahoo.com

Reply from WW:

The 601 and the Corvair are a very good match. A number of people are working on it right now, and we're helping them develop the installation, but no one has flown the combination yet. Considering the engine's success in other airframes, no one should have any doubt that it will produce a very economical and useful engine option for the 601.

As for your request for a price quote on a motor, all of my work in the past 8 years has been primarily in the area of teaching people how to build their own motors. Although I have built many, many motors, the primary aim of my work is to help homebuilders by the original EAA motto of "Learn, Build and Fly." Your typical Corvair conversion costs $2,500 to $3,000 complete. A large displacement motor like the one you mention would be more than enough power for the most ambitious aims of the 601. The parts to build such a motor would be worth something in the range of $4,000. If I were to build such a motor, and supply it with every bracket painted, every piece of safety wire in place, etc., it would become much more expensive than the bare parts would cost you. I'm a very skilled A&P mechanic, and around here, we can bill our time for a fair rate. More importantly, in the length of time it would take me to build your motor, I could help half a dozen guys build their own, answer a few dozen e-mails, write a magazine article, make a housecall to a guy who's ready to fly, and speak to an EAA Chapter or two. Years ago, I was very thankful to anyone in aviation who wanted to take the time to teach me something. These days, given the option, I will always choose to spend my time teaching and sharing. Aviation already has too many expensive engines for people with thick wallets. I would much rather have you be one of the six people who comes away with the positive experience of saying "I built my own motor, learned a lot, saved a bundle, and have a real experience to be proud of."

Subj: 1/2 Corvair! Is This Possible?

Date: 4/8/03 I saw a 3 cylinder 1/2 Corvair in a 1978 Sport Aviation. Is this a hoax? Would it really run?

Micheal J. Fox RN, BSN (Not the Actor), foxyrn@usa.net

Reply from WW:

The 1/2 'Vair is not a hoax, but it doesn't work either. As you may guess, I found it in a Corvair car collection about 7 years ago. It was built less than 10 miles from here. The engine had to be the work of two people: one good, the other a hack. But neither of them knew much about balancing motors either. It would run very, very rough. It would also have 70% of the weight and 50% of the power of a full one. Sure does look nice though; it is a more appealing shape than a 1/2 VW. But it will not work because the opposed motor counts on the mass of the piston and rod on the other cylinder for balance.

Subj: New Video

Date: 4/7/03 William and Grace Ellen,

I received the new video on Friday, but the ice storm in the Detroit area kept our power off until late Saturday. I found the video very helpful in understanding how a Corvair motor goes together. There are so many differences between a flat engine and that of a standard V configuration. They say a picture (or video) is worth a thousand words, and it's true. I've read the Chevy manual and Finch's book, but it was William that took me through the steps required to assemble the short block. Now I understand! Great job!

I have just joined the local Corvair car club and am making the contacts required to locate the correct engine. Will there be an "Engine Assembly Part 2" video? I plan to attend Oshkosh this year and my first stop is to buy both of you a couple of beers. Unless, of course, William would prefer something with an umbrella in it! :-) Just kidding! Thanks for all your help,

Jim Burt, Manual #5301, jim.burt@gm.com

Reply from WW:

Thank you for the nice words about the Engine Assembly Part I Video. We have these readily available for $29USD by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA).

Although we just introduced these three weeks ago, a lot of positive comments like yours have come back. We have already filmed Part II, and it will be available next month. Part II is pistons, cylinders, rings, rod bearings, etc. Part III, which is only scripted at this point, is going to be the cylinder head and valve train video. These will be done for Oshkosh. We also are kicking around the idea of an engine teardown video starring Grace Ellen. If you have other ideas of what you'd like to see, please let us know.

We'll definitely be at Oshkosh, and we'll definitely take you up on your offer. Watch the EAA AirVenture 2003 Forums Page and News from for the Corvair Authority Page on flycorvair.com for the forum schedule as it becomes available.

Subj: Corvair Head Numbers

Date: 4/6/03 I recieved your Manual and video this week and have been pouring over it! I have 3 blocks: 1 with a ZF code, and 2 with the YC code. According to the Manual, these are the 95 hp engines. The head numbers I have been able to read are not on your list. They are 3813516, 3813513, 3786589 and 3786752. Will I be able to use any of these heads in my Pietenpol? I'm looking forward to getting started on my projects and enjoyed your presentation last summer at Brodhead. Maybe I'll see you there again some time. Thanks,

Dale Haag, Pietenpol, West St. Paul, Minn., haagc@uswest.net

Reply from WW:

The engine letter codes you mention could either be an acceptable motor or non-acceptable motor. Letter codes like ZF and YC are only acceptable when the motor is a 1964 model. These same letter codes were also used on earlier engines. Your cylinder head numbers are all from early engines, so I suspect that your engines may be short stroke engines. A careful review of the Conversion Manual will show you that you need to check the crankshaft for the 8409 stamping. The head numbers you mention are not listed in the Manual because they are not acceptable. If your crankshafts have any number other than 8409, they are unacceptable.

Thank you for the kind words about Brodhead. We're looking forward to going back this year.

Subj: Midget Mustang Corvair

Date: 4/5/03 How does the Midget Mustang fair with a Corvair conversion?

Dennis Lithgow, Midget Mustang, denbeclithgow@juno.com

Reply from WW:

The Midget Mustang is a beautiful and also highly efficient airframe. Our friend Paul, who's at our home airport of Spruce Creek, is working on this same combination. I've studied the horsepower requirements, firewall size and shape, and the standard cowling, and feel it would be a good match. We have a dummy engine in Paul's cowl now, and are working on a motor mount for him. Watch www.flycorvair.com for details.

Subj: Static vs. WOT RPM

Date: 4/4/03 What kind of increase in RPM do you see between static and full throttle level fight? Say that 72" Warp Drive prop on the ground run 2650rpm, what would we see in the air on say my gyro? Or what did you see with the 68" Warp Drive on the Pietenpol?

Brent Brown, Autogyro, Fayetteville, N.C.

Reply from WW:

A Warp Drive with the correct pitch setting for cruising at 85mph will turn an extra 150rpm or so in level flight over what it did on the ground. If the airspeed was, say, 150mph, I believe the difference would be substantially greater. The longer Warp Drive props will flex somewhat in operation and contribute toward smaller rpm variations.

Subj: Rear Mounted Starter Kit

Date: 4/3/03 What is the estimated cost of a rear mounted starter kit? Thanks!

Clint Courtney, Troy, Mo., can3g@aol.com

Reply from WW:

Here's a brief history of starters on Corvairs. Prior to my work, virtually all Corvair motors were hand prop. Eight years ago, I developed a front starter setup and sold parts and plans for it. About four years ago, there was talk of developing rear starters. As far as I know, I was the first one to fly one on the back of the motor and fully investigate all of the oil system modifications, etc. After having built and flown several versions of each system, it is my opinion that my current generation of front starter systems is the better way to go. Most of the people interested in the front starter system simply say, "Good, I like it. Show me how to make it or sell me one." Conversely, most of the guys working with rear starter setups all want me to change the design or modify it slightly to fit each of their individual aircraft or separate needs. Thus, it's not economical for me to produce parts for rear starter systems.

The Conversion Manual, available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA), contains the complete story for starters at both ends along with my complete experience developing and flying both. But, I only offer parts for front starters, and the complete story on my latest update on front starters, including simplified bracketry and much lower profile, is included in the Spring 2003 edition of The Corvair Flyer newsletter. Annual subscriptions are available for $20USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $5 for international S&H, including CANADA).

Subj: Corvair for Europa

Date: 4/2/03 I am building a Europa XS, it needs about 120hp for T/O with a FWF of 200lbs approx. Do you know of any Europa builders using the Corvair? The single ignition worries me, can dual plugs be fitted to the heads, and maybe a magneto to fire them, or even the HEI from the Chevy V6? Is the 3100cc engine not as reliable as the 2700cc version, if not then why use the smaller engine for the same weight? I believe that the max bore is 94mm - can the engine be stroked for more cc? I have used 100mm cyls in a Type 4 VW - has anyone tried these in a Corvair? I'm seriously looking at the Corvair for my Europa, and your engine conversion looks a strong contender. The requested info, and any comments would help me decide. Thank you in advance,

Dave McCandless, Europa, daval@iprimus.com.au

Reply from WW:

You certainly take the award for packing the most questions into a single e-mail. All of your questions are answered in depth in the Conversion Manual, available for $59USD in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at The Online Catalog (please add $15 for international S&H, including CANADA).

But let me give you a quick overview. 3100cc Corvairs cost about $800 more to build than 2700cc Corvairs. Additionally, they take a little more care and require a better than average core motor to begin with. The reason why 95% of Corvair builders are going with the 2700cc motor is that it makes excellent power very economically.

Corvairs can be stroked and bored beyond 3100cc, but this requires extremely extensive machine work, and it would be much simpler and probably less expensive to go with another type of motor, especially since you're in Australia.

On your ignition worries, my dual ignition system with single sparkplugs has been proven in hundreds of hours of flight use. My aircraft's first 300 hours of operation were with dual plugs with one set driven by a magneto. Dual plugs is a worthless modification of the Corvair cylinder head, which causes an unnecessary loss of cooling fins. In hundreds of hours of flying Corvair motors on a variety of fuels, I have never fouled a sparkplug. This is very likely due to the fact that the Corvair does not leak oil into the cylinders, has a very strong spark at idle (unlike a magneto) and it has high enough compression to have efficient combustion. As for reliability, electronic ignition systems like the HEI work great for a long time, but fail without warning. Although points will not last as long, they almost always give plenty of warning. This alone makes them superior. Anyone who is critical of points ignition should realize that all aircraft magnetos have points inside.

Several years ago, Europa Aircraft claimed their aircraft would do 200mph on an 80hp engine. The most modest Corvair motor can easily exceed this at very conservative rpm.

Les VanMeter of Chino, Calif., is our leading Corvair/Europa builder. Perhaps you can contact Les through the Europa builders network.

Subj: Cabin Heat

Date: 4/1/03 I have a quick question: Is it an easy matter to install heat into the cockpit with the Corvair engine? Maybe thru the oil cooler? I have have not ordered your book but plan to right after April 15th. Thank you.

Mike, gbgroupmike@hotmail.com

Reply from WW:

The issue with oil for cockpit heat is this: When the weather gets cold enough that you would need cockpit heat, the oil cooler no longer runs hot enough for a good supply. A cabin heat muff off the exhaust system would be the best way to go. Just make sure you have a very good exhaust system and a CO detector inside the plane. Virtually all certified aircraft are done this way, and with good annual inspections, it is a safe system.

Subj: Stock Linkage

Date: 3/31/03 In all of your travels and purchases, do you run across 140 stock linkage? I am looking for a useable set. From reading your info, it looks like you go to a different induction system. Can you help? Thank You

Wade Williams, Wade@DRC-ENG.com

Reply from WW:

My friend Kevin and I own a number of Corvair automobiles. The one characteristic they have in common is that they are all 140 powered. Even Kevin's shortened 1962 Monza convertible has a 140 Powerglide setup in it. When we come across good 140 stuff, we tend to put it to good use ourselves. The carburetor linkage, as you know, is much rarer than the heads. Perhaps someone reading this on the Q&A Page could help you out? Hope it works out for you.

Subj: Pietenpol Update

Date: 3/30/03 Just a note to update the Pietenpol Corvair rebuild. We are at the cooling duct stage and had them all fabricated when we discovered there was very little access to the spark plugs so started to make access doors with Hartwell latches.This failed because the material was too light and they wouldn't close tightly. We solved the problem by fastening the covers with P K screws. Also making cowling openings bigger with a duct tube from the center to the oil cooler on the firewall. Note: Old distributor to be used for pre-oiling and all the clutter in our shop. An old mechanic told me one time that you could tell if the work was getting done by how the shop looked. If it was squeaky clean they weren't doing anything. The weather will govern the installation on the airframe but we are almost ready. More later if you like.

Ray and Rich Hill, Pietenpol, Baxter, Iowa, raydot@pcpartner.net

Reply from WW:

Thank you for the update. Yes, please make sure you send us more pictures as it comes along. Sometimes the simplest solution, i.e. PK screws, is the best.

Subj: Pegazair on Floats

Date: 3/29/03 I received and read your Conversion Manual yesterday. Thank you. After reading that and several of the other builders' Web sites, I have found that I'd like to spend the money and have the 3,100cc modification. I say this because the weight and power advantages are worth the $1,500 to me. I also have come to see the light about going direct drive. Other features I find appealing are: no blower, the OT-10 Cam, your oil pan, a snap ring retainer if possible, a Supertrap muffler if possible, electric start - probably front, and mounting as large a Warp Drive two blade as you'd recommend.

I live on a lake and expect fly my Pegazair on floats. I am not sure the 100LL will often be available. I am willing to spend up to $100 per further pound saved on my engine installation if you have any recommendations on how to do this. I may also wish to try an inflight adjustable propellor at some later date, so anything I can do to help accommodate this would also be of interest to me. Is this a reasonable path? Do you have any further suggestions? Thanks again,

Gordon Alexander, Pegazair, Shakopee, Minn., gordon@curio.com

Reply from WW:

I've recently tested 2-blade 72" Warp Drive props, the largest diameter they make. I have very accurate hydraulic thrust testing equipment, and the motor on the test stand was able to pull 385lbs. of thrust at 2,650rpm. Notably, the prop wasn't that loud. While 385lbs. may not sound as high as some other unobserved claims, keep in mind this is through a muffler and cast iron exhaust manifolds with no cowl, a blunt air scoop and the 32"x30" firewall on the test stand behind the prop. This is also a 2700cc motor. I would not be surprised if a 3100 inside a cowl with a less restrictive exhaust system could pull 550lbs. static. A video clip of this test is on my current video tape, Corvair Engine Assembly Part I, available for $29 in the U.S. at the Online Catalog, or by check or money order payable in USD to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802 (add $15 for international S&H, including Canada).

Your engine proposal seems well thought out and straightforward. I'll be glad to help you out with the conversion parts as you need them.

Subj: Best Day for Sun 'N Fun?

Date: 3/28/03 I plan to attend one day at this year's Corvair College at Sun 'N Fun [full schedule at News From The Corvair Authority]. I have my engine prepped and I think it's ready for assembly. What day of the week do you think would be best for you? I would also like to know if you got the new top plates in and how much they are priced for. Thank you,

Larry Hudson, indyannie_1999@yahoo.com

Reply from WW:

I'd say hit the ground running opening day, April 2. Thursday, April 3, probably will be a good day, too. Look for the crowds to really start rolling in Friday. With this year being the Centennial of Flight, crowds of up to 1 million are expected at Sun 'N Fun.

The new top plates are done and beautiful from the hydro-cutter. We have about a dozen left at the introductory price of $59. You can see yourself in the polished versions, but they're very versatile as you also can paint them or emblazen them with your own personal logo. I couldn't be happier with the final product - it was well worth the wait.

Subj: Hello

Date: 3/27/03 I just thought I would update you on my KR. The stub wings are complete as is almost everything else on the fuselage. I do have to make a rudder and elevator to finish the fuselage. Oh yeah, a cowl too. I have reinstalled the Corvair engine for the last time (I hope). I have also fabricated and installed an air scoop so I can get some serious run time in on the engine. I plan to put a lot of time on the engine this coming weekend as the temps here will be hovering around 50 degrees. Who knows, I just might put fluid in the brake system and go taxiing out in the cul-de-sac. Wouldn't that raise some of the neighbors' eyebrows! It is time to get some more serious building done so I can be airborne by next fall. That is my goal. I will be at SnF on Saturday the 5th and will see you there.

Mark Jones, KR2S N886MJ, Wales, Wisc., flykr2s@wi.rr.com

Reply from WW:

Thank you for the great progress report. This is the kind of news that gets guys motivated to get going in their workshops and build. You have come a long way since we visited your place last summer, and we're just as proud as you are, if that's possible. If you take to taxiing the streets of Wales, be sure you have a photo crew following you. You don't get to see that every day. Please bring all the photos you can to Sun 'N Fun. Saturday, we start out at the Engine Building Tent at 9 a.m., move to the Contact! Forum Tent #3 for William's Corvair forum 10-11 a.m., then back to the Engine Building Tent. I believe the night airshow is Saturday, so you picked a good day to get to Sun 'N Fun. We're all looking forward to seeing you there. Have a safe trip. Grace Ellen.

Subj: Wrong engine

Date: 3/26/03 I purchased a 110HP engine with the wrong letter suffix (RW). Are any of these engine parts usuable? I only paid $75.00, so it seemed worth it just in case. This is a running engine. Thanks.

Tom Wilson Georgetown, Zodiac 601HD (plans), Maine, twilson@clinic.net

Reply from WW:

Your motor, an RW, is a good deal for that price. It is a 1966-68 110 automatic motor. It had a factory option called AIR (Air Injection Reactor), which is an emissions control system that generally has the undesirable open-chambered heads. But, all other parts on the motor will be acceptable to rebuild for flying status.

Subj: Corvair conversions for which planes?

Date: 3/25/03 I am very much interested in getting myself a small Corvair airplane to fly up north and keep on my own land. However, I need to find the correct plane for my purposes. I really like all the info you put out on the Corvair engine, especially the part about the dual points distributor and fuel pump. This is one of the main reasons I considered the Corvair engine. Because my plan is to also have a back up coil, and also backup electric fuel pump, along with a small plane parachute. Just for added precautions. But I need a lot of help getting started and need some good advice from you. I would prefer the plane to hold two average size people and obtain approximaely 5 or 6 gph, probably 20 gal fuel capacity, and cruise comfortably at 100 mph or thereabouts. Is all this possible with the Corvair or am I way out of line? I also have to consider the cost of such an adventure, because funding is out of small wallet. But perhaps you can be of a lot of assistance. Probably just another impossible dream of mine, but I think it would be fun to try. Thank you for your time, s ir. Sincerely,

Michael T. Burke, St. Lawrence, Mass., Twofirst1@aol.com

Reply from WW:

There are a number of aircraft that would meet your description. Our friend Dave Vargesko is building a Wagabond (an experimental PA-17) with a Corvair motor. He will have less than $8,000 in the completed airplane. He's a fairly good scrounger, but anybody could duplicate his efforts for $10,000-$11,000. This plane will certainly do 100mph at 5 or 6 gph. Additionally, since it is a high wing aircraft, it will need no fuel pumps at all. If you fly over inhospitable terrain, or wish to reduce your risk, you should fly airplanes with stall speeds below 50mph. There are a number of other designs that would also meet your needs. The EAA's Aerocrafter guide, available at the EAA's online store at www.eaa.org, is a good place to start your search. Thank you very much for the nice words about my work.

Subj: Pietenpol Motot Mount

Date: 3/24/03 I have been looking at the Manual trying to figure out the motor mount. Could you tell me some of the dimensions from your Air Camper? How far out from the firewall were your rear mounting holes? How far down from the top longerons was the bed (or thrustline)? And did you have to tilt the wing back?

Trying not to reinvent the wheel, Thanks,

Malcolm Morrison, morrisons5@adelphia.net

Reply from WW:

My Pietenpol had the short 1933 fuselage. The cabane struts were vertical. The empty weight of the plane was 732lbs., measured on electronic scales. It had a full electrical system, brakes, tailwheel, etc. The distance from the firewall to the rear bolt hole was 15". If you are building a newer fuselage, this will be several inches less. I highly recommend the longer fuselage. When my plane was painted orange, the thrust line was in the stock location. When it was blue and silver, I built a new mount which moved the thrust line up to be in line with the top longeron. It flew slightly better that way, and I think it looked a lot better.

There's a lot of talk in Pietenpol circles about moving the wing back and forth. This is a dumb idea. With the wing moved forward, remember the landing gear doesn't move, and you're creating an airplane prone to nose over. With it moved back, you can inadvertently change the angle of incidence. The preferred method is to build the plane with the correct landing gear/wing orientation and build the motor mount to give you the correct CG with an appropriately weighted pilot in his seat. We set this perfectly when I built the second motor mount. With a 150lb. pilot, the CG was at 15"; with a 300lb. pilot, the CG was at 20". The axels were at the leading edge of the wing. The plane had excellent ground handling and flew well.

Subj: EAA

Date: 3/23/03 I just read your article in the February issue of the EAA's Experimenter regarding "Resources for Builders and Pilots," and found it very informative. Happily, I have several of the essential books, and will look into obtaining the rest.

I see that you were president of the EAA Chapter in Daytona Beach. I have just been accepted into the ACET program at Embry Riddle for next January, and will be moving there as soon as I can close on the house I've just bought. I've been a member of EAA for about a year now, though not terribly active. I mostly just read the magazines and dream about building my own airplane some day. I have one degree from Riddle already, Air Science, with the associated commercial/multi/intstrument license.

I'm looking forward to becoming involved more with EAA and will look you up when I get myself established in Daytona. Take care,

Marty Dudeck, 688380

Reply from WW:

Definitely look us up when you get to town. We'll be glad to have you over any time we're in town. Thank you for the kind words. I can't recommend highly enough joining the EAA and utilizing all its resources for homebuilders, including Experimenter magazine.

Subj: Parts Prices, Hi Tech pistons

Date: 3/22/03 I need some parts from you. If you send me the cost of them, I will get a check in the mail to you. I need an Aluminum Oil Pan, some Hybrid Studs, a Distributor with the necessary work done, Motor Mount Tray and Prop Hub. I thought I could have you bring these things to Sun-n-Fun, but now I don't think I will be able to be there.

I have the motor disassembled and partially cleaned up; it is scary to start ordering parts for the first one you work on. I contacted Clark's with their c2q form for suggested parts order, but haven't heard back yet. Their catalog boasts the quality of their Hi-Tech pistons - what do you think compared to Forged? Thanks,

Dick Van Fossen, evanfossen1@juno.com

Reply from WW:

Good to hear from you. The prices you requested for these parts include S&H within the U.S.: Aluminum Oil Pan: $269 Hybrid Studs: $66 Remanufactured Distributor: $219 plus your old core Motor Mount Tray and Spools: $149 Prop Hub: $319

You can send a check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or pay by credit card via PayPal at the Online Catalog.

The 2002 Conversion Manual [$59 in the U.S., also available at the Online Catalog] contains a detailed dissertation on cast, forged and Clark's Hi Tech pistons. In brief, we only use forged pistons in flight motors. The qualities that Clark's touts are true for cars, just not for planes where ultimate strength is our bottom line requirement. I understand the concern associated with jumping into your first motor. Study the Manual, familiarize yourself with the parts and don't hesitate to ask questions. We now have a very detailed video on how to assemble the shortblock. It's 84 minutes long, and we're going to have more in the series to complete the entire engine assembly.

Subj: UP AND RUNNING!!

Date: 3/21/03 Happy Happy Joy Joy, It's running smooth. They just don't run when the distributor isn't installed correctly. I chewed my nails all day waiting to get home and try the starter one more time. Two squirts of starting fluid and it came to life. It took care of the clock, pictures, stepladder, and stereo in the garage, but that's a small price to pay for 10 month's work. You should know it gets a little breezy at 1500 RPM in a small room. Oil is about 40psi at 1000 RPM. I haven't checked the head temp yet, but after the first half hour I could still lay my hand on the valve covers. Thanks For The Help. I'll Be Back In Touch Very Soon.

Jeff Kidwell, Hopewell, W.V., whenboy@shentel.net

Reply from WW:

Congratulations! You've worked hard for this feeling of satisfaction, and it's all yours. Looking forward to hearing more good news when you put this engine to work.

Subj: Composite Material

Date: 3/20/03 Thanks for your hospitality when I drove Steve Megill and the guys up. I enjoyed talking about your twin engine design and would like to ask a question. What is the source for that sandwiched fuselage material? Thanks again,

Dick Ripper , EAA 517011, Lakeland, Fla., rwripper@prodigy.net

Reply from WW:

Good to hear from you. It's always a pleasure to have Steve around, and we're glad that you and the gang from EAA Chapter 229 were able to accompany him over for assembly of his shortblock.

I'm answering your question here because I've been getting it a lot since we featured the "Wynne Twin" in the latest Corvair Flyer newsletter. I'm sorry, but I haven't found another source for that composite material. I found it at an aircraft surplus store, bought every piece they had, and only have enough to complete my project with none to spare. Please let us know if you find another source.

Subj: Compression

Date: 3/19/03 What is the maximum compression ratio you would recommend for these engines? I was planning on putting a '61 102 HP head aboard a '65 110 engine. Because of the 49 cc combustion space, the compression ratio would run just over 10:1. As the C/R increases, so does engine heat, stress and chances of detonation, right?? I could mill out a larger combustion space or build the shorter-stroke 145 cid engine instead. Any idea how much HP I could expect running an "early" with the OT-10 (with stock displacement)?? Thanks for any assistance you might give.

John, josandt@netzero.com

Reply from WW:

There are a number of reasons why you would not want to build a 145cid motor. These are outlined in great detail in the 2002 Conversion Manual, available by credit card via PayPal at The Online Catalog, or by check or money order for $59USD (add $15 for international S&H, including Canada) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. The 164cid motors make much better powerplants. While 10:1 could be run on 100ll, I think it is a much better idea to stay closer to the 9:1 compression that is stock on 164cid powerplants. There is no real reason to consider putting early heads on a late motor. It requires machine work and late model heads are readily available.

Subj: : Fine tuning

Date: 3/18/03 I now have 4 hours of run time on the Vair and just replaced the Ivo Prop with a 3-blade 54-inch Warp Drive prop. I set it at 50 pitch. It will run at 2400 rpm static at that pitch. So I need to tweek things to get it up to 2800rpm static. I havn't put a light on the timing yet, but have moved it around a little to see if there is a difference. I have yet to play with the advance, but it's presently set at 30 degrees at WOT. I have put in different needles in the Aerocarb. I can set it so that it's running very rich (engine starts to run rough and load up) to the lean side of average. And there's about 50 degrees difference in egt. Can't get the 100 degrees that Aerocarb recommends. My egt runs about 50 degress hotter on the left bank - adjust the runner length from the carb, maybe? The next thing that I will test is egt difference of each cylinder on one bank to see that my mixture distribution is equal. The engine runs smooth from idle to full throttle and has very good acceleration, so I'm thinking the cam timing is ok. My rear seal is leaking like a seive, so I'm thinking I may have put that seal in backwards. I put it in from the outside.

Del Magsam, "Outlaw Sonex," New Richmond, Wisc., farmerdel@rocketmail.com

Reply from WW:

Again, congratulations on your running motor. The rear seal leaking is most likely caused by forgetting to put the oil slinger between the balancer and the distributor drive gear. It's a simple stamped steel disk, but it keeps oil from being thrown directly on the seal. Yes, the seal does go in from the outside, and the slinger must be put on before the rear cover goes on.

30 degrees of timing advance will not ping unless you have very lean mixtures and high loads. I encourage everyone to use a timing light when doing their initial test runs. When you adjust your propeller for a higher static rpm, say 2,700-2,800, make sure that your timing stays within the limits specified in the Conversion Manual. The distributor may have a slight advance left to go at 2,500.

Subj: BD4 as a 2 place w/ Corvair?--Thanks, I'll order Manual

Date: 3/17/03 Thanks, yes I've decided the Corvair makes economic sense regardless of which plane I decide on. I may go with the smaller KR2 or the CH60l Zodiac. Regardless, I will be ordering the Manual. Thanks again,

Steve Mann, 601 or KR2, Rohnert Park, Calif., smann23@netzero.net

Reply from WW:

Thank you for your order. The Corvair is a versatile powerplant, and can successfully power many of the useful classic designs of homebuilding. The KR2 and the 601 are good examples of planes the engine is well matched to.

Subj: 95 or 110 Heads?

Date: 3/16/03 With a Stromberg MA3 carburetor with the smaller venturi, would it be better to use the 95 or 110 hp heads?

Alex Sloan, Greenbriar, Ala., alexms1@bellsouth.net

Reply from WW:

There is no effective difference in the heads once they are converted according to the Coonversion Manual, available at The Online Catalog Page. A lot of people worry that starting with a 95 will yield a less powerful motor when converted. This is not so. The 95 and the 110 have the exact same port and valve sizes. They have a slight compression difference, nothing significant. From the factory, the main differences were cams, timing and jetting. Since we change all of these things in the conversion process, either the 95 or 110 will yield an excellent conversion with perhaps as little as 2hp difference.

Subj: Safety Shaft

Date: 3/15/03 I purchased a safety shaft from you recently along with an updated version of the Conversion Manual. My engine is going to have electric start and an alternator. My question is simple.... which end do I have the machine shop drill and tap the hole for the safety shaft? Please reply. Machine shop will be getting to my crankshaft and block in the next day or so. Thanks. Blue Skies, Always,

Dave Long, 150pilot@suscom.net

Reply from WW:

The drawings in the Conversion Manual show that Corvair motors are always driven off the flywheel end of the engine. Thus, the safety shaft is threaded into the pilot bushing bore. VW motors are traditionally driven off the pulley end, but Corvair motors are always driven off the flywheel end.

Subj: Corvair Salvage

Date: 3/14/03 I am very interested in your view that the country is over-run with Corvair cars and engines. I am somewhat reluctant to destroy a restorable car in a junkyard, as a collector will be deprived of just one more opportunity to do his/her thing after I leave. Nonetheless, I am scouring around, and in Greeley, Colorado, I have located two cars, and if I remember, they are both too early for my use. And the owner in Greeley wants $300 each for his. I located a place in Denver (south suburb) fairly near where I live, and several weeks ago the man there told me he had three of them, which he would sell for $150 each. While I don't consider three to be a whole lot, I thought I might be satisfied with that. However, when I went back to make a deal for the three, it turns out he only has one, a 1965 model, to sell at all. I recall you bought 12 or so for $1000, and I wanted to see a selection like that so I could really choose a nice one for myself. Frankly, I wanted to buy three books from you, so I could restore three (two for me and one for a friend) but now I am unable to do anything of the kind. I am not a happy camper. Can you provide any ideas on what I can expect in real life toward getting perhaps a newer 1968 or 1969 model? Am I wrong to think that a better choice? By the way, this guy does have a 1964 model but I don't know if that is acceptable.

I called a junkyard right in Denver, and he was on his computer (I guess) and he said he could locate one in Oregon, and one in Michigan. Is THAT wonderful? $500 each. Plus shipping. These things don't sound plentiful at all. The guy that has one here for $150 claims that dealers are NOT hanging on to them as the age gets older. Off to the melting pot!! That is not going to help the availability or the price. I do not know WHAT to believe. Can you help?? Yours sincerely,

Richard G. Alps, Littleton, Colo., Richardalps@aol.com

Reply from WW:

Your concerns are unfounded. First, the 1965 motor for $150 right under your nose would make a great conversion. The motors are not rare. Today in my hangar, a man dropped off and gave to me 2 1964 motors. These also would make good conversions. The details of this are covered in your Conversion Manual [available at The Online Catalog Page]. This man gave them to me because they were leftovers from a pile of motors he bought in North Carolina, from which two very nice conversions were built. This was a very nice gift, but it is also a good indication of how little the motors are really worth. Not in a million years will a stranger pull up in front of your hangar and give you two O-200 cores (value $8,000) for nothing.

As explained in the Conversion Manual, forget looking at junkyards. The motors we want are in the hands of Corvair fans nationwide. There are at least five national Corvair junkyards owned by CORSA members that would gladly sell you an engine for half of what your local $500 ripoff artist wants. In fact, if he's shopping from Oregon, he is probably buying one for $250 from the Corvair Underground and doubling the price. If you really can't find one locally, you should just contact them directly.

A number of people have had trouble finding an engine after looking for a week or two. But, stop looking in junkyards and contact CORSA and you'll have much more success. If there is not a local Chapter near you, go to the oldest auto parts store in your town (not a chain store) and ask the senior counterman if he could put you in touch with a Corvair person. Trace one or two of these leads, and you'll find plenty of motors.

Subj: Engine Selection, Zodiac Motor Mount

Date: 3/13/03 Just ordered your Conversion Manual today and I have a couple questions for you. I found a 1964 engine locally that has been sitting in a dry shed for 30 years and apparently the rings must be stuck because you can't turn it over. Does the condition matter since it will be completely overhauled or should I look for a better one. Price is $125.00 including two older engines. I'm building a Zodiac CH601 HD and had intended to use the Jabiru 3300 until a friend reminded me about the Corvair. Reliability is the most important issue to me and from what I read and hear this engine has it along with the affordability.

Another question is about an engine mount for my Zodiac: Where do I get one or would I have to make it myself? Appreciate your help. Thanks,

Dick Schmidt, Zodiac CH601 HD, Menasha, Wisc., rschmidt8@new.rr.com

Reply from WW:

To my understanding, all the 601 series aircraft are the same from the firewall forward. I am looking into providing motor mounts and parts for these, the same way I already do for KRs and Dragonflys, etc. When the time comes, I will undoubtedly have at least motor mounts available for you. All of my other existing conversion parts are 100% applicable to 601s.

$125 is a little steep for a motor which will not turn over. If you can talk him down to the $50-$75 range, it may be worth it. In many cases, I prefer to spend a little more money on a better core because they tend to be a little less work when overhauling.

Subj: Case Studs

Date: 3/12/03 The top case studs are rusted off where the nuts are screwed over. What should I do about this?

Dean Mitchell, Bay Village, Ohio

Reply from WW:

The top case studs on motors were exposed to water and grime thrown off the rear wheels of the cars. In states with salty roads, this tends to rust the ends of the studs. In extreme cases, the studs need to be replaced. Frequently, it is easier to find a perfect case than to replace the studs. Note that Larry's Corvairs in L.A. has a supply of excellent condition cases which they will UPS to you. Call them for details. If just the tops of the studs are shot, you can consider having a machine shop counter-bore the pads on the cylinder heads so that the nut will move closer to the centerline and have full engagement after you re-assemble the motor.

Subj: Parts - Oil Pans

Date: 3/11/03 What is the status of your larger capacity oil pans? How far in advance do we need to order? Thanks,

John Krumrine, Zodiac 601XL, College Park, Penn., jqk4@psu.edu

Reply from WW:

The first order of oil pans sold out very quickly. The new order is arriving this week, and I will have them on the shelf and in stock continuously from here on out. The popularity of the Corvair conversion now justifies me stocking all of the parts in my catalog for immediate shipment. Previously, there have been delays in shipment on some items, but this year, the growing acceptance of the motor justifies an even greater investment on my part.

Subj: 1963 Corvair

Date: 3/10/03 Found a 1963 Corvair , the engine number is ti029zf. Is this an engine I can use? The car was an automatic transmission.

Cary Howard, Monticello, Fla.

Reply from WW:

Every week I hear from people who have gone out and purchased Corvair motors from $100 to $900 because they wanted to get started before buying the Conversion Manual. Your money spent on a 1963 engine is unfortunately wasted. The Conversion Manual contains all the acceptable letter codes and head numbers, plus instructions for selecting a good core motor. I encourage anyone seriously contemplating the purchase of the motor to call if they have an immediate question. Arming yourself with the information contained in my Corvair Conversion Manual and studying it before throwing money at a core motor is the correct approach. Manuals are available in the U.S. for $59, payable by check or money order in US Dollars to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog Page (add $15 for international S&H, including Canada).

Subj: Sun 'N Fun

Date: 3/9/03 I hope to make it to Sun-n-Fun in April . . . do you plan to be there? I have a few Corvair 164 engine parts to bring to ask questions about. Thanks for all your work in making an affordable flight engine possible.

Gary Kaplan, Mt. Juliet, Tenn., gary@garyglenwood.com

Reply from WW:

Good to hear from you. We will be building engines all week at Corvair College during Sun 'N Fun, April 2-8, 2003, in Lakeland, Fla. Our full schedule is at the News From The Corvair Authority page. This is exactly the kind of participation we're looking for at this event. By all means, bring your Corvair parts (cleaned as outlined in the Conversion Manual) and learn with the rest of the group.

Subj: Aerobatics

Date: 3/8/03 Having read some of R. S. Hoover's comments as linked from Ron Wanttaja's Web site about building an inexpensive airplane I got quite interested in something like a Piet, Corben or Fly Baby until I looked at the prices of (mostly runout) 4 cyl. Continentals (65-100 hp) in a year-old issue of Trade-a-Plane (ouch - runout or not they are NOT inexpensive!). Therefore I am quite fascinated about the idea of a Corvair engine for inexpensive flying.

Now to my Subject; I do have an interest in Aerobatics. Would the Corvair be good for "Sunday afternoon aerobatics," say in something like a Baby Lakes or Starduster SA-900? (The literature Pete Bowers sent me on the Fly Baby even mentions its "excellent aerobatic ability".)

Also, if I get infected by the speed bug, how would the Corvair do in, say, a 1 seat Midget Mustang or RV-3 (both originally designed for 90-100hp Continentals despite the subsequent horsepower races among homebuilders)? Sincerely,

Mark Boberg, Oak Harbor, Wash.

Reply from WW:

You're quite correct in your assesment that the Corvair is an inexpensive alternative to the small Continentals. They are good engines, but the high price of parts for them means that most Continentals have been run on shoestring budgets for many, many years, and thorough overhauls on them are astronomically expensive.

The Corvair has obviously flown a number of the original airframes you mention, like the Pietenpol and Corben Baby Ace. Numerous Corvair Conversion Manual owners are installing them in Junior Aces and Fly Babys.

Everyone has a different definition of what "aerobatic" is. If you consult FAR Part 23, Pete Bowers and Curtis Pitts, you're going to get very different answers. You need to develop your own personal experience in aerobatics to judge your real interest. I have flown aerobatics in jets and 450hp Stearmans, and personally hard core aerobatics with negative maneuvers are not for me. I do feel that normal flight maneuvers and recovery from unusual attitudes should be in every pilot's skill set; if you have proper training, your Corvair-powered airplane can handle any of these maneuvers.

The RV-3 was never designed to fly on 90 or 100hp. You can check the Van's Web site; I believe the minimum size listed is 150hp. On the other hand, Midget Mustangs do fly well on 85-100hp. I'm currently looking into a 3,100cc/Midget Mustang installation at our own airport. It looks like a very good match.

Subj: Engine Parts at Sun 'N Fun

Date: 3/7/03 I intend driving down to Sun 'N Fun this year. I was hoping that I could pick up some engine parts while I'm there. Will you have available a 10/10 reground crank with safety shaft and studs? I can bring mine down with me as core exchange. I'm also interested in the prop hub, the light weight oil pan, and a remanufactured dual ignition distributor. Please let me know so that I can pack my distributor and crankshaft. Thanks,

Neil Hulin, Zodiac 601XL, Cincinnati, Ohio, nhulin@hotmail.com

Reply from WW:

Good to hear from you. Let me take a moment to explain our crankshaft situation. We did a little less than 100 crankshafts last year on an exchange basis, but for various reasons only got about 40 good cores back. This temporarily depleted my on-hand supply of cranks. Currently, I am offering the same regrind and prep to drop in status that I always have, but it will be done to your own crank. The turnaround time, because the work is done at 2 different machine shops, is about 3 weeks. If you send us your crank now, we will be able to give it to you completely modified at Sun 'N Fun.

All the other parts you mention I will have on hand at Sun 'N Fun. You can bring your distributor core with you. Distributor cores are not a problem, as virtually every one is rebuildable and I have approximately 200 cores on hand.

Looking forward to seeing you at Sun 'N Fun. Our schedule is at flycorvair.com News from The Corvair Authority.

Subj: Turbo

Date: 3/6/03 My recent review of your Web site indicates that you have completed a great amount of R&D since I last studied your development of the Corvair engine conversion for aircraft. I am very interested in your new motor mount and will be ready to order your prop hub and other components when I receive the New Manual and determine what other newer parts or assemblies you have available.

You have listed the Christavia Mark I as one of the experimental aircraft that has been built with the Corvair engine. Turbo normalization is also of interest to me for maintaining power at mountain altitudes.

Dick Schoen, Christavia Mark I, St. Paul, Minn.

Reply from WW:

I am very close to having a turboed direct drive motor that I believe will be the answer to the quest for more power while retaining the simplicity of direct drive. I have the engine in my shop now, and I have gone to great lengths to minimize any of the changes so the system can be of benefit to guys who already have built motors. I'll put the whole story in the summer issue of The Corvair Flyer newsletter.

Thank you again for staying in touch. As you know, the work I've done has been a big part of my life, and while it's very popular these days, I will always remember the guys who recognized my efforts and supported me early on.

Subj: Ring Gap

Date: 3/5/03 Today I started the reassemble of the engine with the able help of one of our EAA Chapter members. He is a licensed engine mechanic. We have the crank and camshaft installed and it checked well using the Plastigage. He requested I give you a ring and see what you suggested for the piston ring end gap clearance. He was looking at the Manual but thought that perhaps it should be a little more than the listed specs as the engine is being used for an aircraft. What are your thoughts on it? He showed me how to correctly increase the gap by filling the ends of the rings. Neat. Thanks for you help.

Alex M. Sloan, Greenbriar, Ala., alexms1@bellsouth.net

Reply from WW:

You are quite correct in assuming that we like to run the ring end gap at the looser end of the range. When a cylinder is bored for a forged piston, and the rings are slid down in the bore to check, I like to see the ring gap closer to the upper end of the limit rather than the lower end of the limit. One of the great advantages of air cooled engines is that they can be run hot for several minutes. To do this without damaging the engine, the ring gaps cannot close, otherwise the cylinder wall will get scraped badly. Comparatively, a liquid cooled engine will boil off its coolant under the same circumstances. I have found almost all new ring sets to check out at the upper end of the limit, but it is a simple matter to insert the rings in the bore and check them with a feeler gauge to be sure.

Subj: Flybaby

Date: 3/4/03 Starting a Flybaby project and wonder if the Corvair engine would be suitable?

tkorange@localnet.com

Reply from WW:

Yes, it's a good match. There are even a number of guys working on two-seat Flybaby/Corvair projects. Although most Flybabys were flown on 65hp Continentals, its sturdy construction allows the use of more powerful Corvair motors. The Corvair's simple nature complements Peter Bowers' design philosophy with the Flybaby.

Subj: Nice job

Date: 3/3/03 Hi, just a quick note. A friend here in Casper, Wyoming, is finishing a Pietenpol with Corvair power and has showed me your fine Manual, Corvair Flight Engines for Experimental Aircraft. For the past 13 years, I have owned and driven Corvairs; 5 are running, one turbo. I'm a Mechanical Engineering teacher, with some specialization more in diesel engines. Thought I would say congratulations on such a fine book and Web site. Your articles and book are so very well done and technically correct. You really have a thorough understanding of the subject and it is a treat to see things done so well. I wish you the best!

Ardell Knudson, aknudson@caspercollege.edu

Reply from WW:

Thank you for the very nice compliments. Coming from someone who has both a background in the mechanical world and education, I take it as a real compliment. The work in the 2002 series Conversion Manual is not only the result of years of work on Corvair engines, but also the accumulation of a lifelong interest in things mechanical. Along the way I had many teachers, and I'm sure I never thanked them all properly, but a lot of the credit belongs to them. I'm sure many of your students feel the same way about you.

Subj: Wag Aero Sport Trainer

Date: 3/2/03 William, I'm looking to build the Wag-Aero J-3 Cub with the shortened wing option (also the L-4 Observer conversion). Anyway, what do you think of the Corvair in this plane? Also, why not use the 140hp engine? I own a '63 110 Monza convertible and LOVE the engine. Thanks for your time.

Rick Davitt, rickdavitt@shrinkpackaging.com

Reply from WW:

The Corvair is a good engine for either the standard J-3 or the shorter wing versions. A standard J-3's engine is of course only 65hp, and I have seen clipped wings fly well on motors as small as a C-75. Although both of these engines make their rated power at low rpm, the difference in thrust per horsepower is not nearly what most armchair theorists would have you believe. The Continentals turned 72" diameter props. The Corvair can easily turn a 68" or 70" prop, and the additional horsepower of the Corvair makes for an engine installation with substantially more thrust than the small Continentals. If anybody tells you differently, simply ask them which Corvair motor they tested. I have found that the people who blindly repeat theory have never tested anything.

The whole story on 140s is covered in the Conversion Manual, available by check or money order for $59USD (add $15 for overseas S&H) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. You can pay by credit card via PayPal at the Online Catalog. But in a nutshell, the 95 or 110 motor converted according to my Manual actually makes more power below 3200rpm. Since all of the operation of a direct drive motor in an airframe like an L-4 is below this rpm, it is the optimum motor. Additionally, the 140 is the only motor in the Corvair line known to drop valve seats. For these reasons, I recommend the 95 and the 110.

Subj: Corvair College

Date: 3/1/03 I'm going to try to make it to your place prior to Sun 'N Fun, and also to SNF. What will I need besides long block? Do you have any TRW pistons? Will you have any prop hubs available? I'm planning on using front mounted starter and alternator accessories. I already have Corvair fuel pump and 12 plate oil cooler.

Greg Jannakos, Zenair 601, Ga., gpjann@juno.com

Reply from WW:

The next step on your engine would be the connecting rods, pistons, rings and cylinders. Your Conversion Manual details exactly which parts these are, and what needs to be done to them. I generally do not keep a big stock of pistons and cylinders and similar items on the shelf because they are readily available from the sources listed in the Conversion Manual, and I avoid being the middleman on standard parts. Once you have these items on hand, the next step would be to bolt on the cylinder heads, which of course need a valve job before they're installed. Cleaning and painting the pushrod tubes and the rest of the valve train components before hand makes the assembly go smoother. If we have to take time to do these in my shop, it reduces what can be accomplished in a weekend. My pre Sun 'N Fun Open House is the weekend of March 15-16. All of the conversion parts that I sell, like prop hubs, aluminum oil pans, hybrid studs, etc., will be available.

Our Sun 'N Fun schedule is posted at News from the Corvair Authority. All Conversion Manual owners are invited to build up their engines for free at Corvair College, just as we've done at the past three Colleges. Everyone is always welcome to watch and learn. The only difference is that this year's College is at Sun 'N Fun rather than at my hangar, and they charge admission. Their Web site is www.sun-n-fun.org. Looking forward to seeing you in Lakeland.

Subj: High compression Corvair

Date: 2/28/03 I just ordered your book on Corvair conversion, but I have a question I am sure is not covered in it. I will be building a 194 cid engine and I would like to use as much as 12:1 compression on it. I will not do this to gain horsepower, but rather to retain the 75% hp to a higher altitude. I would also want the additional compression down the line when I convert it to use alcohol fuel. My question to you is, would this be possible without hurting the reliability very much? If you do not know the answer, could you put me in touch with someone that can answer it? By the way, I will be putting it in the lightest weight BD-4 ever built. Thank you for your time.

Dale Neddeau, BD-4, dneddeau@hotmail.com

Reply from WW:

Your question is certainly not run of the mill, but it is far from the most unusual one I've ever received. I do not believe that raising the compression ratio will retain as much power as you think at altitude. The motor would also detonate if the slightest mistake was made about opening the throttle too far at low altitude. A naturally aspirated motor loses power at altitude because the same volume of air has fewer molecules in it and because the effective cylinder pressure is dropping. Your proposal would counter the second factor, but not address the first. I would honestly suggest considering a turbo instead. I am continuing my work on direct drive 2,700cc turbos, and I think it would be a much more promising altitude engine.

As for running the motor on alcohol, most of the high end Corvair powered sand dragsters run on alcohol. Guys like Bob Sutcliffe, whose number is in the Manual, have a fair amount of experience with this. My personal experience with alcohol is limited to motorcycle drag racing. The horsepower improvement potential is about 15% on a naturally aspirated engine. Against this, peak power air/fuel mixture is only 6:1, giving the engine a ravenous appetite for fuel. And the main problem: it's horribly corrosive and will attack almost everything in a standard fuel system, including the tank, the lines, the inside of the engine.

A 2,700cc turbo Corvair motor would probably be a much better bet for your ultra light weight BD-4. (Note: BD-4s are not normally within the Corvair's hp range.)

Subj: TITAN AIRCRAFT'S NEW T-51 3/4 SCALE ALL-METAL MUSTANG

Date: 2/27/03 Hi William, always enjoy your articles on what's going on in the aviation/Corvair engine world! I shared a few e-mails with you last year regarding the Corvair engine's ignition system, and about the old '66 Dodge pickup and engine with 86,000 original miles I found and bought. I have overhauled several engines myself over the years and served as a crew chief/mechanic on Hueys in Vietnam and Germany. Always enjoy engine work and do most engine and other repairs on vehicles I own.

Now I am truly interested in buying a kit airplane to use a Corvair engine in. Last year I was interested in the Loehle wood and fabric P-51 Mustang replica, but when I mentioned using the Corvair engine with their P-5151 model, Sandy Loehle told me they had not heard of it, so never considered it. When I told her the weight of the engine, she thought that the weight may be too much for their design. They had no plans for attempting any tests, but now with subject Titan aircraft coming out, they may become more "adaptable" to compete.

Do you have any information on subject aircraft's potential for using the Corvair engine? The Titan T-51 is gorgeous looking in the pics I have seen, and since the P-51 was always my fav WWII airplane, I would be thrilled to build and fly one! Here is the Web site for the Titan: http://www.titanaircraft.com

Thanks for any help you can provide, although it appears you have very limited time, so I feel fortunate if I hear from you. Sincerely,

Wendell McGinness, Titan T-51, Gig Harbor, Wash.

Reply from WW:

We saw this plane in person at its Sun 'N Fun debut last year. It drew a huge crowd. The pictures don't do it justice. It's very nice. I believe the intended engine for it is a 912S or a 914. They are working very hard to keep a decent useful load and stay under 1,232 pounds for the new Sport Pilot rule. If you're really interested in this plane, you might want to call them and ask if it could be flown on an O-200. If the answer is yes, it's a good possibility the plane could be Corvair powered.

I have recently been contacted by a company in Australia building a 1.6:1 gearbox for the Corvair. More information is due in the coming weeks, but this aircraft might use such a setup to turn a more scale prop. I almost never suggest using a gearbox, and this one is as yet unproven. But, I'll keep an eye on it for everybody.

Subj: Corvair in Ercoupe?

Date: 2/26/03 Would the Corvair be a good engine for the 415C Ercoupe?

jleonard@cox-internet.com

Reply from WW:

Most Ercoupes were powered by 75 and 85hp Continentals. The Corvair, at 100hp, could certainly power the aircraft. All of the difficulty of mating the two would be in getting approval from your regional FAA office, and operating the aircraft under the restrictions they might impose. If you're considering such a project, contact your local FSDO on the approval procedure and flight limitations.

Subj: Dual ignition

Date: 2/25/03 Do you have a dual ignition set up for the Corvair and possibly dual plugs? I have had to put a plane down in the water due to ignition problems, so I hope you understand the reason for my question. Thank you.

Paul Mallard, papaquack@aol.com

Reply from WW:

The Conversion Manual details all the developmental work and experience I have with dual ignition. My current dual ignition setup has two of all the heat sensitive components: points, coils, etc. Yet it retains the simplicity of single plugs. It is flight proven with hundreds of hours of service. I sell these distributors, complete, including Priority Insured shipping, for $219 at the Online Catalog, or you can send a check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802.

Subj: Change to Manual info

Date: 2/24/03 I think the phone company changed the area code on you...Page 21 shows CORSA phone number as 709- and it is now 630....you might want to change that...

Bob, rwbtoy@internetcds.com

Reply from WW:

Thanks for the tip. For everyone else reading this, CORSA is the Corvair Society of America. It is the national group for owners' of Corvairs. It is a large group, with state and local Chapters.

Subj: C-150s and Corvairs

Date: 2/23/03 I'm looking at a couple of Cessna 150 airframes, less engines. They can be had for next to nothing. Is this a candidate for a Corvair engine, and if so am I opening a can of worms? Looking forward to hearing from you.

Ron Jones, Shelby Twp., MI

Reply from WW:

A Corvair would certainly power an early model Cessna 150 nicely. The earlier model 150, the better; they were lighter and had lower drag. Here's the catch: You'll have to receive special permission from the FAA after filing proper documentation, and there will be restrictions on how and where you can operate the aircraft. The documentation may have to include a report from a licensed engineer on such items as engine mount design, etc. It can be done, but I highly suggest you contact your regional FAA office and learn all the details before you actually acquire the aircraft.

Subj: How to clean the block?

Date: 2/22/03 What is the best procedure to clean the block? If sandblasting, what media do you use? If some cleaning fluid, what is used? Or other???

Thanks, Greg, g_geer@blomand.net

Reply from WW:

The 2002 Conversion Manual contains an extensive section on cleaning techniques. In short, never sandblast anything on the motor. This restriction includes glass beading. The only acceptable blast media would be Walnut shells or plastic. Glass or sand will upraise and destroy the fit under the bearing shells, in the lifter bores and on the mating surfaces. Gunk engine cleaner, pressure washing and carb cleaner and brushes are a much better way to clean the aluminum parts on your Corvair motor.

Subj: Just Starting

Date: 2/21/03 Hi to you William. My name is Charles Storey and I'm just starting to consider building because the cost of buying aircraft has gone into orbit and just doesn`t seem to fit my wallet. I've been talking to people about building and the subject of engines came up and I was told that your Corvair engine is going to be the recommended engine for this. Now I've said all that to say this: I'm no Mechanic. I'm good at carpentry, and just about all home repairs, and can change a plug or two. I can take one part off and put another one on, so is this going to be too big of a job for someone like me to tackle, or should I just hope to find one already done. Stuff like this really confuses me. Any thoughts or suggestions will be most helpful, because as you know, money doesn't grow on trees. Thanks for your time. Hope you can help.

Charlie Storey, RAMBLER444@aol.com

Reply from WW:

Many years ago when I started my work with Corvair motors, it was with the sole intention of helping out guys just like you. A big part of the reason I chose the simplicity of direct drive, air cooled and simple systems is because it's the only practical engine to teach people to build for themselves. Complex engines would be beyond the scope of safely teaching first-timers to build for themselves. By and large, a Corvair motor, as converted, requires no machine work for you to do. It requires only careful assembly and light fabrication. When a first time builder expresses the same concerns you have, I'm never worried. In my experience, first time guys exercise more care and tend to build by the book rather than with a been there, done that mentality. Converting the Corvair motor is much easier than building the simplest airframe.

Occasionally people ask about buying a motor that's "rebuilt." I sincerely recommend against this. In the past years, with my help, dozens and dozens of Corvair motors have been rebuilt. The owners are justifiably proud and I cannot think of a single one which is for sale. Occasionally, stories surface of engines for sale, but I know from our records that we've never met the seller, and he doesn't own a copy of the Conversion Manual, so I largely suspect it's just an overpriced car engine. You're always much better off to buy a good core motor and rebuild it yourself. You'll know a lot more about the motor when it's done, you'll have the pride of having created it, and you'll be putting your trust where it belongs, in your own craftsmanship.

Subj: Corvair College #4

Date: 2/20/03 I had a request for more info on the upcomimg Corvair College. What is the cost & exact dates/time (since Sun 'N Fun is running Wensday through Tuesday).

Michael Amick, mkamick@edge.net

Reply from WW:

Our Sun 'N Fun schedule is posted at News from the Corvair Authority. All Conversion Manual owners are invited to build up their engines for free at Corvair College, just as we've done at the past three Colleges. Everyone is always welcome to watch and learn. The only difference is that this year's College is at Sun 'N Fun rather than at my hangar, and they charge admission. Their Web site is www.sun-n-fun.org. Looking forward to seeing you in Lakeland.

Subj: Corvair for Australian Piet

Date: 2/19/03 G'day, have just started on a Piet long fuse, (plans from Andrew P) and would like to use a Corvair. As you are probaly aware they are a bit thin on the ground over here so would like to know whether you have looked at shipping a suitable core and some of your other mods to Oz. I have noticed on one of the UK sites that you have sent some there. If you can let me know if it can be done and an estimate of shipping costs I will start talking to customs at this end to see where I stand.

Regards, Arthur Johnson, Townsville, Australia, aejonhson@email.com

Reply from WW:

It is true I've shipped aircraft motors and cores to Brisbane and Birmingham. Incidentally, I've shipped Manuals to such far flung places as St. Helena, Sai Pan and South Africa. The last time we sent a motor to Australia, the shipping was about $500 by air freight. Contact me when you're ready.

Subj: CORSA motor

Date: 2/18/03 Thanks for returning my e-mail, and the info about the prop. I was a little alarmed to hear about the potential destructive flaws with this motor. I hope you can enlighten me some more to what they might be. The motor I have is a genuine Corsa motor. Serial number TI 216 RB. Mileage - 63,000. It was overhauled according to the 1965 Corvair shop manual. I purchased it from an ex- helicopter inspector in England, now in Adelaide, Australia, who originally rebuilt it in England and brought it out to Australia some years ago. It is the 4 carburetor engine, which was converted to a single Aircraft Carby underneath, which I have now changed to a Dual side draught Webber, one half of the 45mm carby feeding each side of 3 cylinders, also underneath (I will not be flying over 5000 feet). It has not been run since re-built. However following is what has been done to the motor internals:- Crank crack tested using X-Ray. Crank dimensionally checked. Cylinder head cooling fins cleared of casting flash. Airways opened up. Cast iron valve guides replaced with aluminium bronze guides. Valve seats re-cut and valves re-ground and assembled with new springs. GM cast alloy pistons replaced with TRW forged alloy pistons. Double capacity oil pump fitted. Camshaft replaced with Otto TB-10 shaft to improve lower RPM performance. New hydraulic tappets. Sump replaced with cast aluminium ribbed cover. GM main & big end bearings replaced with TRW CL-77 High performance shell bearings. All oil seals replaced and push rod "O" rings replaced with Viton rubber seals. Engine re-assembled with shake proof bolts and hardened flange cylinder hold down nuts. Crankshaft, Prop Hub, Harmonic Balancer and starter ring dynamically balanced. Pistons and con rods Statically balanced. Also Thrust Bearing:- Based on American experience (Bernie Pietenpol), It is of the later type with a thrust face on both halves. All parts replaced are either TRW or OTTO parts. Is this sufficient not to have to strip the motor down again, or are the potential problems not covered by what has been done. Please let me know what is needed to be done, and what your Manual is now worth. Also do you accept VISA Card. Hoping to hear from you again.

Regards, Roger Foster, randgfoster@hotmail.com

Reply from WW:

Thank you for your detailed records. It sounds like the engine had a first class rebuild. The only item on the engine that I would change would be the cylinder heads. Although this sounds extensive, it's not. Virtually all the other parts on the motor will bolt right to them. The only difference is that the 110s require a slightly different rocker arm. Your cylinder heads, as they are, are worth about $400USD. You could easily find someone with whom to exchange them for a fully rebuilt set of 110s or 95 heads. The 140 heads do not make power at direct drive rpms. This is covered in the Manual, which costs $59, plus $15 for overseas S&H. You can pay by credit card via PayPal at the Online Catalog. Although several people are interested in Webers, the best setup is yet to be determined with this carb. I strongly suggest running both barrels into a common plenum. A single barrel feeding a long intake track on the Corvair can send a resonant pulse down the tube. This is eliminated by feeding a common plenum. It's not a problem on the car because the intake is short.

Subj: Excavating an Engine

Date: 2/17/03 Hi, Thanks for the manual and video tape at San Geronimo, TX. I have the 1965 Corvair shop manual and after reading the engine and transaxel removal instructions and special tools needed, I am still wondering what to do at the junk yard when I go to pull the engine myself. What process do you recommend for the "Pull the engine from a car sunken into 20 years of dirt"? O.K. Then how much would the shipping be on one of your engines to San Antonio?

Richard Elder, San Antonio, Texas, relder@flash.net

Reply from WW:

We had a great time in San Antonio. The best way to remove the motor from a late model car is to jack up the back end of the car till the bumper is 30" high or so. Remove the bolts around the bell housing, with the exception of the bottom two, and disconnect the motor from the rest of chassis, wiring, fuel line, etc. With the carburetors removed, you can lower the car down, disconnect the rear motor mount by the harmonic balancer, and take the bottom two bolts out. When you jack the body up this time, the motor will sag down and it can be slid away from the transaxel and out from under the car. If the car has an automatic transmission, you'll have to disconnect the three bolts from the torque converter to free it from the flex plate. Richard Finch's How to Keep Your Corvair Alive has step by step instructions on his method of engine removal.

I have traditionally sold dozens of engines inspected and guaranteed to be rebuildable for $299. This served me well to jumpstart the re-emergence of the Corvair motor, and got a lot of people going. Today, the popularity of the motor leaves me little time for tasks that guys can easily accomplish in the field, such as acquiring a core motor. The popularity of the motor dictates that I spend more time doing things like driving to Texas to teach you and other builders. I heartily encourage you to get your core motor locally. Not only will it be cheaper than me having to ship it to you, your tracking it down and liberating it from a junkyard will provide a much more dramatic beginning to the story of how you built your own airplane motor.

Subj: Carb Ice

Date: 2/16/03 Does the Conversion Manual deal with adding fuel injection? I'm paranoid when it comes to carb ice.

Ron Mills, Burbank, Calif., MILLS42@aol.com

Reply from WW:

The Conversion Manual covers the issues surrounding fuel injection, and my opinion that carburetors are a much better idea for amateur aircraft builders. Plenty of airplanes have automatic carburetor heat; an Ercoupe is a good example. There is no need to be paranoid about carb ice. If you read the Web site closely, on the Carb Ice Page you'll learn that fuel injected engines are not immune to carburetor ice. The complexity of installation and high pressure fuel pumps associated with fuel injection are things of which to be leery. People have flown millions of hours on carburetors, even without automatic carb heat. This has been done safely. Amateur fuel injection does not have a safety record to match this.

Subj: Looking for Engines in Indiana

Date: 2/15/03 William, I just ordered your Conversion Manual a couple days ago using your PayPal method [Online Catalog]. My wife told me to just order it by mail, but I want it yesterday.I wanted to know if you know of any places in the Indiana area that may have an engine or two laying around? If they are what I need to get the job done, I will travel to Illinois or Ohio. Thanks in advance and I'm looking forward to getting your book. I'm hoping to put it in a KR2S some day. Thanks again.

Bob Glidden, KR2S, Martinsville, Ind., glidden@ccrtc.com

Reply from WW:

Thank you for your order. I'll research my records and also invite anyone who reads your request here to contact you directly with any leads in your area.

Subj: Engine break-in runs

Date: 2/14/03 Hi William. I have two hours of run time so far, 4 half hour sessions. On the last run, I did 30 seconds of WOT at three different pitch settings. The Ivo Prop range is 30 to 90. With it set right in the middle (approx 60) the rpm was 2300. I turned the prop back 1 turn (approx 54), I got 2400 rpm. And then I turned it back another turn (approx 48) and got 2500 rpms. Is the Ivoprop so far off that I don't know what pitch it is at, or does that static rpm sound right for a 60 inch prop. I have the carb set pretty decent. I haven't put a timing light on it yet. How many hours should I run it before I do extended WOT sessions. And how long should I do WOT at a time. And what static rpms should I try to achieve with a 54 inch wood prop.

Del Magsam, "Outlaw Sonex," New Richmond, Wisc., farmerdel@rocketmail.com

Reply from WW:

Good to hear from you. First, before anything else, verify your maximum timing advance. For ground runs and break in, use 30 degrees of total ignition advance as an upper limit. You'd like all this advance to be in before 2,400 or 2,500rpm.

The propeller pitch sounds like it's in the right neighborhood. As you know, I'm no fan of Ivoprops. Keep a very close eye on the hub for any signs of separation or rough running behavior. The Ivoprop I sold to Bob Bean for his Lycoming-powered Tailwind disintegrated in the 1999 Sun 100 Air Race. If you choose to fly this prop, please pay very close attention to it.

You want your static rpm to be approximately 3/4 or more of your planned WOT level flight rpm. I would not use less than 2,500rpm static in a plane like a Pietenpol, and with a smaller diameter prop in the 54-58" range, I'd shoot for a number like 2,750 or better. Before any runs at all, make sure that your engine is completely baffled, and you run it with the cowling on. Before I fly a motor, I like to see a 30-45 second run with the airplane blocked up to its maximum angle it will see on climb out to verify that fuel flow at full power is adequate. Keep an eye on the oil pressure gauge also. With all of your baffling and cowling in place, and the engine properly broken in and warmed up, you can run the engine at full throttle as long as the cylinder head temperature is in the green arc. Before the engine is fully broken in, I would limit WOT to about 2 minutes.

Subj: Crankshaft dampeners

Date: 2/13/03 Are crankshaft dampeners used on the Covair engine? What brand do you use and do you sell them? Thanks,

Howard, howash@juno.com

Reply from WW:

Almost all 164cid Corvair motors left the factory with harmonic balancers. The standard harmonic balancer will fit any model engine I recommend for flight conversion. Most of these balancers have damage to the rubber after 35 years. Dale Manufacturing has rebuilt thousands of balancers, replacing the rubber with cast urethane. These balancers are available from the suppliers listed in my Conversion Manual. They are not expensive, and I have used one on every motor I have ever built.

Subj: Reverse rotation 'Vair

Date: 2/12/03 In your Conversion Manual you mention that you are working on a reverse rotation Corvair engine. I'm currently kicking around the idea of a twin BearHawk and was wondering what luck you've been having and how far along in the process you are.

Dr. Andrew Rekow, BearHawk, Waterloo, Iowa

Reply from WW:

I am building the reverse rotation motor currently in the shop. I expect it to be done just after Sun 'N Fun, and I'll have a complete list of the details that go into it in the Spring issue of The Corvair Flyer newsletter.

Subj: Christavia MK IV

Date: 2/11/03 Would the 4 place Christavia MK IV be severely underpowered with the Corvair motor? Thanks for any info.

Joe, antjuju58@yahoo.com

Reply from WW:

I am not familiar with the Christavia MK IV performance details. I did note that the Christavia 2-seater was originally advertised to fly on 65hp, but the general consensus of builders was that 90 or 100hp was a practical minimum. This leads me to believe that the four-seater would require more power than the Corvair could economically deliver.

Subj: Just started

Date: 2/10/03 I just started tearing down my engine, and I have a few questions. I bought the engine from the Corvair Ranch in Gettysburg. It is out of a '66 and has the RD Towanda suffix.

When I removed the first head, I saw that the one piston had a hole burnt through it. I'm planning on replacing all the pistons and rods, so my question is, would this type of damage have created any other problems with this engine that I should be looking for? The engine turned over, but could it have bent the crank? Thanks,

John A. Krumrine, Zodiac 601XL, State College, Penn., jqk4@psu.edu

Reply from WW:

It is not likely that the motor was damaged at all by having the weak, stock, cast piston let go. I would be particularly careful when cleaning out the oil cooler and the oil galleries, as this metal went somewhere in the motor. The people who rebuild your connecting rods will be able to check the straightness of the rods. A standard rebuild as I recommend in the Conversion Manual (available by money order or personal check for $59USD plus $15USD for S&H for those outside the U.S. payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Product Catalog Page) will work fine on this motor.

Subj: Sonic Detectors

Date: 2/9/03 On Page 17 of your 2002 Manual you refer to a "stand-alone sonic detector" in a back issue of Contact! magazine. Doing word searches on their Web site on their back issue summaries turned up nothing using the word "sonic" or the word "detector." However, using the work "knock" turned up:

Issue 28: "Steve Parkman develops a stand alone engine knock sensor. Complete DIY plans are included."

Q1. Is that the issue to which you were referring?

Q2. Also, what oil temp min and max limits would you suggest for Take-off, Climb and Cruise? Thanks,

G. Andris Vaskis, Manual #5236, vaskis@gte.net

Reply from WW:

Yes, that is the Contact! issue to which I'm referring. Pat Panzera, panzera@experimental-aviation.com, who is the current editor of Contact!, is a Corvair engine builder. Also, Steve Makish, Boca Raton, Fla., is flying his Corvair-powered KR2 with an MSD knock detector. These are available from hot rod shops.

I would consider 160F to be the lowest oil temp I would fly at; 180F would be a better idea. Ideally the motor would operate above 212F to boil off any condensation or entrained water in the crank case. New motors will occassionally hit 260F on a climb. After a few hours of operation, you'll notice the oil temperature will drop 20-30 degrees due to reduced internal friction in the motor. We run fully broken in motors on synthetic oil. I don't have specific information on what is too high for synthetic oil, but I strongly suspect you could run it 30-40 degrees hotter than non-synthetic oil without damage.

Subj: John Deere Alternator

Date: 2/8/03 William, we have the new John Deere Alternator that you recommend in the Manual but have run into a problem in mounting it so it can be driven. Our question is, "If we drive it from the original balancer pulley it will be turning in excess of 8,000 RPM,-- Will it stay together or will it tend to throw the segments out of the armature?" We have clearance to add a smaller pulley to the face of the balancer but the mounting would be more difficult so we would like to drive from the balancer pulley. Please advise us as to what you recommend? We are anxious to get this engine running so we can be ready for the fly in season. Respectfully,

Ray and Rich Hill, Pietenpol, raydot@pcpartner.net

Reply from WW:

We have an awful lot of flight time driving the John Deere alternator from the stock pulley, so I can assure you that it works, even though the rpm is high. The design of the unit is such that only the magnets are rotating, and they are bonded to the inside of the cup-shaped outer housing. Thus, centrifugal force holds them in place instead of straining the bonds. I have momentarily turned one of these 16,000rpm by accident, and it did the unit no harm. Reducing the pulley diameter is technically a good idea, but not necessary.

Subj: CH701

Date: 2/7/03 Will this engine work in a ch701 or is it too heavy? Thanks,

Miles, M150@aol.com

Reply from WW:

The Heintz family has told me directly that they do not want engines which weigh 200lbs. or more in the 701. Despite the fact that their 701 brochures have pictures of engines like O-200s and EA-81s, which weigh as much or more than a Corvair, they do not encourage installations like this. A number of people who liked the 701, but wanted to use a Corvair, are now working on an aircraft called a Pegzair from Canada. You can find out more about it in the EAA Aerocrafter catalog.

Subj: Forged Pistons

Date: 2/6/03 Mr. Wynne, Turns out Larry @ Larry's Corvair is recommending boring out a '60 cylinder (not a '61 cylinder) to the 110 HP standard piston size. Then fasten it to a late model case and crank. Top it with a '61 102 HP head (9:0 compression). Run standard size 110 forged pistons on a late model crank. It seems to me that the boring process increases the volume of air being compressed - therefore, the CR must increase. Larry says no, it doesn't. He insists that he's done this same operation for other aircraft builders. Can you help here? Also, do you know if the '60 heads are heavier? Too heavy? Would appreciate any help you might care to give. Thanks.

John, josandt@netzero.net

Reply from WW:

The operation as Larry described will work. The Corvair's advertised compression ratios are slightly optimistic. I haven't done the calculation, but would suspect Larry is correct that the compression ratio is just a little over 9:1. '60 cylinders are slightly heavier than others, but it's not much, maybe 2 pounds for the whole motor. The '61 heads should weigh just about the same.

Subj: I'm inspired now... hand me the wrench!

Date: 2/5/03 Thanks again for visiting our EAA meeting last night. It was definitely an exciting presentation and I am now pretty certain that I will be embarking on a Corvair project this year... as soon as I get through the wedding I'll be getting your Manual and looking for an engine core. (Maybe sooner if I can manage it!) I've realized that working on these engines is not nearly as scary as I had come to believe previously. Looking at a typical modern car engine can be a bit imposing, but when you see the Corvair motor, you realize that there really isn't that much to it. The thought of building an engine for a homebuilt has gone from being something that I was going to leave to the experts into something that I both can and want to achieve myself, with the expert's friendly guidance and the benefit of experience gained by those who have done it before me. Like you said, learning by doing instead of merely buying the engine will help me gain knowledge and skills that will make me a better airplane builder and a safer pilot. As far as I can tell, it would be hard to beat a Corvair for a good engine to learn these skills on... it's not all that complicated! You guys have a great attitude that truly reflects the spirit of sport aviation that has attracted me to experimental aircraft for longer than I can remember. I will definitely see you guys at Sun 'N Fun to learn even more.

Will forward a copy of the EAA meeting report when I'm done. Thanks again to you, Gus, Arnold, and Dave... everyone enjoyed it a lot and were genuinely excited about Corvairs!

Mike Whaley, merlin@ov-10bronco.net, MerlinFAC@cfl.rr.com, Webmaster, OV-10 Bronco Association

Reply from WW:

Thank you for your kind words. We got your newsletter and it looked great. We look forward to seeing you again at Sun 'N Fun.

Subj: Corvair engine for Zodiac XL

Date: 2/4/03 Just thought I'd drop you a quick note to say that I'm building a Zenith Zodiac 601XL, and I've been following with some interest the recent indications that you may be working with a Zenith builder to create a FWF package for the XL. If there is any truth to that, I just wanted to add myself to the list of interested builders. The Corvair conversion seems to be just the ticket for an economical powerplant for my XL (and yes, I already have a copy of your Manual!). Any word on when you might realistically have a FWF package available, if that is still your intention? Thanks.

Mike Fortunato, Zodiac 601XL, mike@city-commercial.com

Reply from WW:

I am still working toward that package. Please note that I'm working on it independently, not with the factory. The Heintz family remains neutral on alternative engine installations which they have not personally tested. While they have been fairly supportive, the development of the combination is being done solely by me here. I'm very busy prepping for Corvair College #4 and Sun 'N Fun, but I suspect I could have this done by Oshkosh.

Subj: Bell Housing

Date: 2/3/03 William, Thank you for taking time out of your schedule to reply. Actually after I sent the e-mail to you, a fellow called who had a Corvair about 25 minutes from the house. The motor turned over so I offered him $100 for it. He accepted, then ended up giving me the whole car. It was the RF designation and had matching heads of the 110 non smog variety. Haven't taken it apart, but everything looks ok. Since I made a deal with the guy in Little Rock, I feel obligated and will make the drive. I shouldn't have been so hasty, but he has my word. Lastly, will the bell housing for the standard transmission work, or will I have to obtain one from an automatic? Best Regards,

Ed Jones, Xocouple2001@aol.com

Reply from WW:

We're answering this on the laptop while driving down the road. Gus is in the back seat and says thanks again for dinner in San Antonio. On the bell housings, either one can be used. They're completely interchangable. Keep in touch. We'll see you soon.

Subj: Engine Choices

Date: 2/2/03 When you have a wide choice of Corvair engines, is there a particular one you would prefer? Also, they will sell me an untested engine for $350 and a running engine for $450. Is there any advantage to buying the running engine if I plan to rebuild it anyway?

One final question. I have a Subaru Legacy wagon and hope to pick up the engine in my car. I know about all the measurements, but do you know of anyone who has ever tried to transport a Corvair engine in this size vehicle?

Thanks for your help. I 'm hoping I'll be able to get to Sun 'N Fun and meet you personally.

John A. Krumrine, Zodiac 601XL, State College, Penn., jqk4@psu.edu

Reply from WW:

The Corvair, stripped of the outer sheet metal, will certainly fit in anything pretending to be a station wagon. In looking for a motor, generally we're looking for a 1965-69 95hp or 110hp. All the letter codes and serial numbers are contained in great detail in the Conversion Manual, available by money order or personal check for $59USD (add $15 for S&H outside the U.S.) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog. Please note that either motor, the 95 or 110, will produce the same 100hp when converted for aircraft use. It does not matter which one you start with. For $450, the motor would have to run pretty darn well. This includes idling well and not smoking. Running motors have the advantage that they are almost always rebuildable at a lower cost. The price these people ask demands the motor be in very good condition.

Subj: Corvair Prop

Date: 2/1/03 I have obtained a Corvair Corsa motor which has already been modified for Aircraft use, with an output of approximately 100 hp, but I am currently remodeling it to suit my requirements. It will be going on a cantilever low winged single seat aircraft. What I would like to know is, what type of ground adjustable propeller do you recommend, and what diameter. The engine will have a maximum rpm of 3300 revs. I need a ground adjustable prop, as at this stage, I do not know what pitch I will need and I will have to experiment. Can you assist me please. Hoping to hear from you.

Roger Foster, randgfoster@hotmail.com

Reply from WW:

I will be glad to help you in any way I can to ensure you safely operate your motor. Anything I comment on comes from first hand testing. The Internet being what it is, a lot of advice is tossed around by people who have never tested anything.

Corsa refers to a 1965-66 140 or 180hp Corvair motor. I have flown both of these motors in the direct drive form and they perform poorly. Additionally, they each have potentially destructive flaws which are not shared by the vast majority of non-Corsa Corvair motors. A lot of people use the term Corsa loosely, so perhaps you do not have one of these engines, but it is a serious matter, so I ask.

Before you fly a motor, you need to know what is inside. Despite the fact that I have sold thousands of conversion manuals, many people do not follow recommendations I make. It is a free world and this is OK, but many of these motor are later sold as "converted according to WW's manual" when they are not really close. A lot of this is small but crucial deviations which can be corrected without too much work. It is well worth checking into what you have. As for props, there is only one adjustable one which is flight proven on the Corvair, the Warp Drive. I would start with a 66" two blade without tapered tips. This can be trimmed if it proves to need it. We have sold a lot of these, they cost about $600. They work very well. Write back with any question you may have. I highly suggest a copy of my Conversion Manual, available by money order or personal check for $59USD (add $15 for S&H outside the U.S.) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at our Online Catalog Page.

Subj: Corvair College Curriculum

Date: 1/31/03 Thanks for the new info. I have a question about bringing a motor to Corvair College. Do we break them down, clean them, and rebuild them there? Or do you start by taking motors that have already been broken down and cleaned? If the latter, then I would just need to buy a rebuild kit from say Clark's Corvair and bring a good clean motor? Just wondering what all specific tasks are performed at the event. If you could send me a list of what all is covered, I would appreciate it. Thanks.

Greg, g_geer@blomand.net

Reply from WW:

The best thing to do is to bring a completely cleaned motor with all the replacement parts and a prepped crank. We can assemble it at the event. We will not have the cleaning equipment from my hangar on the airshow sight.

Subj: Zenith CH 701

Date: 1/30/03 Hi, I was wondering if anyone has attempted putting a Corvair engine into a Zenith CH701? Plans state an installed wieght of 200 lbs. Thanks.

Paul Hodgson, amehodgson@hotmail.com

Reply from WW:

The Heintz family has told me directly that they do not want engines which weigh 200lbs. or more in the 701. Despite the fact that their 701 brochures have pictures of engines like O-200s and EA-81s, which weigh as much or more than a Corvair, they do not encourage installations like this. A number of people who liked the 701, but wanted to use a Corvair, are now working on an aircraft called a Pegzair from Canada. You can find out more about it in the EAA Aerocrafter catalog.

Subj: Motors in Arkansas

Date: 1/29/03 How are you doing? I enjoyed very much the Jr. Corvair College in SA. Started looking for motors immediately after and couldn't come up with any. Finally, a guy in Houston sent my e-mail out to a list serve of Corvair fanatics and a fellow in Little Rock, Ark., sent an e-mail. He will let me have 3 to 4 motors for $75.00 each; does this sound reasonable? Also do the head numbers have to match or will any of the recommended head numbers act as suitable pairs? I am ready to get going on a motor and appreciate your help! On your reply I will go to Little Rock to pick these motors up if you think this is reasonable. He has indicated the motors are complete w/o carbs. Have a great day!

Ed Jones, xocouple2001@aol.com

Reply from WW:

Good to hear from you. The deal doesn't sound bad, but there may be motors closer to you. Dave Morris, who ate dinner with us during the Alamo event, told me that there were several in his home town. I am sending out a roster in the Winter 2003 Corvair Flyer newsletter of all the addresses of the guys at the Jr. College so everyone can stay in touch. You may want to get in touch with Dave if it seems like a long drive for the motors you are considering.

Subj: Propeller Diameter

Date: 1/28/03 I discussed the possible performance of the Zenair CH 601 HD using the 100 HP Corvair engine with Sebastian Heintz. He felt it probably would work in the plane, but with a weight penalty. He advised using a prop with a diameter of 68 to 70 inches and not less than 66 inches. Again I would appreciate your feeling on the prop size. As usual thank you for taking the time to answer my questions.

Paul Mallard, papaquack@aol.com

Reply from WW:

I have a lot of flight time on 68" Warp Drive props, and we have sold and flown 66" ones as well. You can turn these props 3000rpm without them getting noisy and inefficient because they have very thin tip sections with very high allowable mach numbers. These props are about $600.

Subj: Storch engine

Date: 1/27/03 I'm thinking of building a Storch type aircraft, such as a Preceptor Stol King or a Ragwing Stork RW-20. They need to swing a large prop. They need at least 100hp, big torque and weigh under 250 lb.

1) Would a Corvair Engine work without a PSRU?

2) Real Aircraft Engines have a special Main Bearing to keep the Crank in place. Does the Corvair? Thanks!

Gary Van Meter, gvanmeter@cox.net

Reply from WW:

The Corvair does have a double sided main thrust bearing, which has a perfect track record of flying for the past 42 years.

People have flown Corvairs with PSRUs, but they have a poor track record and none are available now. They are non-existent because the motor works so well as a direct drive engine. There are no PSRUs available for O-200s for the same reason.

The Ragwing is a very light plane and I am not sure it is approved for 200+ pound motors.

Subj: Fuel lines

Date: 1/26/03 One technical question. My Avid has all 1/4" fuel lines, from the outlet in the tank, through the header tank. Do I need to replace all of those with 3/8" fittings? I think I know the answer, but thought I'd ask anyway.

Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net

Reply from WW:

Yes, use 3/8''. You might get by with 5/16", but 1/4" will not work.

Subj: Vari-EZ

Date: 1/25/03 I am interested in a Corvair powered Vari-EZ project. I noted in your Daily Q&A letters that you were working on a mount for a customer. What is your current price for such a mount? May I contact the person you made the first one for to get their advice as well? I am coming to Sun 'N Fun & thought of making a side trip to your place of business either before or after. Are you planning any Corvair Colleges around that time? I already bought your book @ OSH & look forward to seeing you again.

Michael Amick, Vari-Ez, Franklin, Tenn., mkamick@edge.net

Reply from WW:

The Vari-Ez installation that I worked on belonged to my neighbor Arnold Holmes. However, Arnold and his father are planning to relocate to a grass strip, which the Vari-Ez could not fly from. Thus, they have sold the Vari-Ez and put their full emphasis into completing their Corvair-powered Dragonfly project. The Vari-Ez project was put on Ebay and sold to a newly formed EAA chapter in Minnesota that is enthusiastic about completing and flying it. The motor mount I built was custom made to fit the pre-existing cowl, and firewall hard points. I did not build a jig for it, but it was similar in design to the motor mounts that I build for Dragonflys.

Our Sun 'N Fun schedule is posted at News from the Corvair Authority. All Conversion Manual owners are invited to build up their engines for free at Corvair College, just as we've done at the past three Colleges. Everyone is always welcome to watch and learn. The only difference is that this year's College is at Sun 'N Fun rather than at my hangar, and they charge admission. Their Web site is www.sun-n-fun.org. Looking forward to seeing you in Lakeland.

Subj: Pietenpol Aircamper

Date: 1/24/03 I am hoping to build a plane in the next couple of years and I am really interested in the old, low and slow style of flying. I have a question on the useful load of the Aircamper with the 100hp Corvair engine. Is the useful load of the airplane controlled by the airframe structure, or by the power of the engine? I am 250lbs. and would like to take a passenger up with me. That doesn't leave much for fuel. I am attracted to the Aircamper because of the ease of construction and it being primarily wood. If you would rather pass these questions on to another group I would totally understand. Are there other airframes out there that you would suggest with similar ease of construction, low initial cost, and perhaps a little more payload available? I have read some of the other airplane specs, but have also heard that talking to someone with personal knowledge or exposure to these other airplanes is invaluable.

Once again, thanks and I hope that I am not taking too much of your time.

Tim Moody, Pietenpol, tj_moody@yahoo.com

Reply from WW:

The Pietenpol, if well built, can fly well above the early published gross of 1150 pounds. Here is a good example: My plane weighed 734 pounds, and truly could have been 30 pounds lighter. My friend Gus who weighs 280 flew passengers who weighed 220 with 16 gallons of gas in the tank. This is about 1330 pounds. The CG was within limits and the plane flew well. The Piet is one of a handful of planes which behave like this. If you were putting a lower power engine on it, the gross would be limited by minimum climb performance to a lower weight. At 1300 pounds, a good Piet could still pull 4 Gs without damage.

Subj: Conversion costs, pistons

Date: 1/23/03 Hello Mr. Wynne, A couple of questions: What is the estimated cost of converting a Corvair engine, for the average person, at this time? Also, how to know the difference between cast pistons and forged pistons? When they are in the engine, can it be done by taking the head off and looking at the top of the piston, or by taking the pan off and looking at the bottom? Thank you very much for your time and trouble.

Ed Cody, #5259, mcalder_2000@yahoo.com

Reply from WW:

Good to hear from you. A forged piston will have the number L2206 on the head. Most guys are spending $2800 to $3200 to completely overhaul and convert a motor, including a core.

Subj: Insurance for Homebuilts

Date: 1/22/03 There has been a lot of talk about insurers not providing coverage for auto engined homebuilts. This could be real trouble for us and I was wondering what you thought? Best wishes,

Mark Deacon, wrenchspinner1@yahoo.com

Reply from WW:

Several people have alerted us to the issue that the Corvair is not currently on Falcon Insurance's list of approved engines. The Corvair has an excellent track record, and I am currently working to find out what Falcon's requirements are and gather documentation of Corvair-powered flight to meet those requirements.

EAA HQ is very concerned about issues for grassroots aviation. I am quite sure HQ will urge anyone with their approved insurance program to cover 100% of homebuilts which fly off their restrictions. It should be understood that there are great differences between auto insurance coverage and aviation coverage. In my experience, auto insurance companies will always live up to their obligations, despite small mitigating factors. Conversely, aviation insurance has a very hit or miss record. I have watched while companies like Avemco have paid out obvious fraudulent claims, and then watched companies use the smallest of unrelated details to weasel out of legitimate claims. I personally plan on carrying only liability insurance on my flights, as I do not believe that average insurance companies will pay hull claims on experimental aircraft, even though their rates are extremely high.

Subj: San Antonio

Date: 1/21/03 Just a note to tell you how much I enjoyed attending the Corvair College in San Antonio. It got me reved up to get started. I just swept out the old shop and rolled the table out that is supporting my '65 110 engine. On the way home, my son told me he has the hots to get started too. Anyway, you will be hearing from me as things progress.

John Weikel, Kerrville, Texas, jandd@maverickbbs.com

Reply from WW:

Ttank you for the nice note We had a very good time ourselves.

Subj: Parts

Date: 1/20/03 I am one of the people in cold Michigan who is getting started on a conversion of a Corvair engine. I will need one of the distributors you modify, a prop hub and one of the aluminum oil pans you mention in your Manual. I have my Chevrolet manual and my other books you recommend about engines. At this point I am confused by all the reading but I will work it out. You ask me to let you know if I found a source of engines in this area; I got one in Bangor, Mich., from Jerry's Garage. I didn't follow your advice and accepted one that was partially dismantled. As you said, some parts are missing. So far I have not gotten any response from the fellow I bought it from about changing for one whole engine. I can't say I would recommend doing business with him unless you are VERY certain you know what you are buying. On the other side of the coin, I bought a complete engine from Clyde Stanton of Middleville, Mich., and he is a pleasure to do business with; he has several Corvairs and many parts for them. He e-mailed me that he is going to Florida and would try to stop in to see you while he is there. If he does stop, you will know him when you see his Corvair Motor Home he drives. I had never seen one of those before. It would be fun to own one. I would like to see either a picture or a drawing of how you mount your carburetors on your manifolds; all the pictures I have seen so far are from the front of the engine and do not show the carb itself. Let me know the way I can order the parts I mentioned so I can get them here. Thanks,

Dick Van Fossen, evanfossen1@juno.com

Reply from WW:

Good to hear from you. Thanks for the tips on core motors; we have a number of guys in your area who have asked for a source and we will pass the info along.

As for the parts:

Pan, $269

Prop hub, $319

Distributor, $219, and we need your old one as a core sent to 210-11 Cessna Blvd., Port Orange, FL 32168. If you dont have it, add $45.

All prices include Priority, Insured S&H in the U.S. You can send a personal check payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or use a credit card via PayPal at the Online Catalog.

Subj: Prop question

Date: 1/19/03 A prop question for you. I have a 3-blade Warp Drive 70" prop with standard hub. I hope I can use it in a 2-blade format for my Avid/Corvair. Can you sell me a high-HP 2-blade prop hub for my current blades? If the blades turn out to be too long at 70", can I shorten them or should I buy new shorter blades (like your 68")? Thanks again.

Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net

Reply from WW:

Yes, Warp Drive blades can be shortened. They are fairly easy to cut and smooth out, and can be shortened from 72" well down into the 50"s. The material is of very uniform density, and they will generally be balanced if you remove the same length off each tip. I am a Warp Drive dealer, and can sell you the correct hub.

Subj: A Funky Corvair

Date: 1/18/03 William, I have a 1946 Funk that is supposed to have a C85-12 powerplant. I purchased the airframe from a gentleman that wanted the powerplant. Thus I am interested in installing a Corvair auto engine. I scrounged up a Corvair engine about 14 years ago for one of those some day projects. According to the engine serial # it appears to be a viable powerplant for conversion. However, I would like to be certain it is a suitable engine for the Funk. What do you think? If so, I need to order your Conversion Manual and get a liability release off to you so that I can get started on the some day project. Thanks for your input.

Paul Peterson, Fargo, N.D., Peterson58104@cableone.net

Reply from WW:

You have a Funk airframe? They're terrible airplanes. If you give me your address, I'll leave with a trailer tonight from Florida and relieve you of this burden. I couldn't allow a fellow aviator to suffer with such an aircraft.

I'm just kidding. A Funk is a personal favorite airplane of mine. I always stop to get a good look whenever we come across one. The only picture of a plane hanging on the wall in my shop is a Funk we saw last year at the SAA Fly-In at Urbana, Ill. It is a very good match for the Corvair. You should look into how much rework it would take to get it to qualify as amateur built. Let me know what you come up with.

Subj: Hand Prop Installation

Date: 1/17/03 If a Corvair motor were to be installed without a starter, could the flywheel be eliminated also? It seems like the prop alone should have enough rotational mass to keep the motor running. What would the installed weight be of an installation like this? I would like to build up a hand-propped motor with nothing more than a small lawn-tractor belt-driven dynamo for electrical power. Thanks,

Doug, sputnik@aug.com

Reply from WW:

You are quite correct that the motor uses the prop for a very effective flywheel. The only type of "flywheel" I use is a ring gear for electric starting. A motor set up as you propose could be brought down to 200 pounds ready to fly.

Subj: Smart Plugs

Date: 1/16/03 Can the standard 190 engine be ignited with smartplugs?

Jerry Plumlee, tplumlee@juno.com

Reply from WW:

Although I saw a Rotax 503 run a very convincing display on smartplugs, the last I heard they were still working on four strokes. The operation is dependent on compression ratio, and must be specifically tailored to each engine.

I have worked several years to come up with a very reliable dual ignition system for the Corvair, and it is flight proven in hundreds of hours in the air. Although smart plugs are interesting, I have little need to pursue another ignition system.

Subj: Front Starter

Date: 1/15/03 What are the part numbers for the: Nissan ring gear for front starter? Alternator drive pulley?

Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net

Reply from WW:

All the front starter stuff is being redone to make it simpler and more off the shelf. I want to get this wrapped up in a month or two, but I will have parts that are much easier to find, and have the brackets in stock.

Subj: Coils

Date: 1/14/03 Which coils do you use?

Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net

Reply from WW:

The best coils are Bosh blue coils with the internal ballast resistor.

Subj: Suitable Aircraft

Date: 1/13/03 Hi William. I'm looking to build a two-place airplane on a limited budget. I recently came accross your Web site and I'm very excited about the Corvair conversion. I've narrowed my choices to the Littner Whisky IV, Sonex, Nesmith Cougar and Sonerai II. I know the Corvair can be used on the Sonerai. Do you know if any of the other designs can use the Corvair? Any advice you can give me will be greatly appreciated. Thank you.

John Minton, Kodiakmarine8550@aol.com

Reply from WW:

If you are looking for a plane which can be powered by a Corvair, you should look up the EAA Aerocrafter manual; it lists all of the planes available in the industry. Look for all the ones which list an O-200 (100hp Continental) as a good motor and this will be a good guide. Write me back with any specific questions you may have.

Subj: Distributor Recurve

Date: 1/12/03 I have a rebuilt distributor that I got from Corvair Underground, with the points plate removed. I read in your book that you will re-curve my distributor for a modest price. I also need the bolts to mount everything. If I ship my Dist. to you with the dual points plate, the points rotor and cap, will you re-curve it for me? And how much will I need to send you? Thanks for your time

Fish Fischer, Ore., fishhole@pacifier.com

Reply from WW:

We now sell completely re-manufactured distributors, which precludes the need for getting them from suppliers. The cost on these is $219, which includes Insured Priorty S&H. These are complete with cap, rotor, etc. We need your old distributor as a core, or a $45 core charge.

Please note that I much prefer to work on our own distributors, but guys who already have a rebuilt distributor body and want me to do the rest of the work on it can for a limited time send it UPS to the hangar, 210-11 Cessna Blvd., Port Orange, FL 32128. Cost breaks down as follows:

Points Plate $39

Points $20

Recurve $40

S&H $20

Total $119

Subj: Corvair Carb

Date: 1/11/03 Would a Corvair turbo carb be ok to use on a Corvair aircraft engine ? Thank You

Dave Clark, Ga., Dclark356512@cs.com

Reply from WW:

The turbo carb has been flown on a naturally aspirated Corvair. But it's heavy, and expensive. There are a number of other carbs I'd choose first. I discuss carbs in detail in the new Conversion Manual, available by money order or personal check for $59USD (add $15 for S&H outside the U.S.) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via PayPal at our Online Catalog Page.

Subj: Who can do repairs?

Date: 1/10/03 THE CORVAIR CONVERSION LOOKS COOL AND COST EFFECTIVE. WHO CAN DO REPAIRS ON THE ENGINE? DO YOU HAVE TO BE "CERTIFIED"? I WANT TO BUILD A HOMEBUILT AND AM LOOKING AT ENGINE OPTIONS. IF I DECIDE TO CONTINUE. I QUICKLY FOUND OUT THAT THE ENGINE CAN BE THE MOST EXPENSIVE PART OF THE EQUATION.

NOTE THAT ALTHOUGH I AM NOT AN EXPERT, I DID DO 2 FORD 289s. IT WAS FUN AND THE SECOND ONE RAN FINE. THE FIRST ONE FAILED BECAUSE I WAS TOO YOUNG/FOOLISH AND USED THE WRONG SEALER ON THE OIL PAN.

PETE, Ptfoof@aol.com

Reply from WW:

Experimental aircraft are built and maintained, including the engines, by amateurs. None of the parts need to be certified.

Subj: You've Convinced Me

Date: 1/9/03 I just ordered your Manual and tape yesterday, and I'm anxious to get them. I'm building a Zodiac 601XL and just went through your Q&A pages and was very pleased to see your remarks on the Corvair engine and the 601 combination. I have a 0 time O-235 engine sitting in my shop that I had intended on using on my project, but started looking at other (less expensive) engine options figuring I could sell my Lyc and help finance the rest of my project.

I like what I've read in your Web page. I travel a lot to Florida in my job, and hope I can perhaps stop by and meet you at some point. I'm only about 2 hours from The Corvair Ranch in Gettysburg and have already contacted them about paying them a visit. They quoted me $350 to $450 for an engine. I called a local salvage yard where I have parked two Subarus and one Toyota in the past, and they have several Corvairs, but they're not sure what they have. I hope to go exploring tomorrow.

Anyhow, you've convinced me to sell the Lyc and build (or rebuild) my own Corvair engine. I like the idea of knowing everything about the insides of what will be flying in front of me in the future. Thanks,

John A. Krumrine, Zodiac 601XL, State College, Penn., jqk4@psu.edu

Reply from WW:

Thank you for the nice words. Feel welcome to stop by the hangar anytime, but call to make plans as we are there odd hours. We will get your Manual right out when the order arrives. Let me also encourage you to subscribe to our newsletter, The Corvair Flyer. You will get a free copy with your Manual to look over.

An O-235 is a good motor and they bring a lot of money in good condition. Your plan will inject a lot of cash into your aircraft project. There is a lot to be said for knowing your whole plane, including the motor.

You will find a lot of friendly people in the land of Corvair flyers. Welcome to the club.

Subj: Distributor

Date: 1/8/03 I spoke with you last week about a rebuilt distributor. I have my distributor packaged and ready to send. Do you have a UPS shipping address that I can send it to?

Chuck Snyder, Greenbrier, Ark., rgilliom@alltel.net

Reply from WW:

You can ship it to the hangar address, 210-11 Cessna Blvd., Port Orange, FL 32128.

(Everyone, please take NOTE: The Port Orange USPS somehow recently seceded from Daytona Beach, and at some point will end the grace period for delivering mail that is not addressed to the hangar as "Port Orange." So please note the change to Port Orange in your address books.)

Subj: Spark Plug Removal

Date: 1/7/03 Greetings William! Thank you for bringing some excitement in building a KR2S. I had the plans since '83 and finally am starting on it: Engine First! I am in no rush and started to break down a 66 RH engine that I recently purchased and broke one of the spark plugs in the hole. Easy-outs do not budge it even with a breaker bar. Any suggestions?

Richard L. Cowles, KR2S, Madison, Ala., richardcowles@knology.net

Reply from WW:

Try either Kroil or Mouse Milk. These are two extremely good penetrating oils. Failing this, heat it with a propane torch and melt a wax candle into the threads. When it cools, it may be loose. If this fails, heat the head in an oven at 400F for an hour. Use a turkey baster and pour cool water through the plug threads.

Subj: Corvair engine for high elevation use

Date: 1/6/03 I am interested in knowing if your engine is suitable for me. I live in Bogotá Colombia South America. I am thinking (1st time builder) of constructing a 2 seat airplane or biplane that will be able to fly here. The elevation in our city is of 8,355 feet MSL (really, check out a Jeppessen chart for apporaches into Eldorado Intl Airport). I know of a lot of people flying behind Rotax 912 engines here but I believe they are expensive and underpowered. I am looking at a biplane because of the ample wing area (double) and because I do not plan to cruise at mach numbers!! I am also interested in the KR2S and own a set of plans for a SuperKingfisher 2 place amphibian.

My questions relate to:

1) Will I be able to build (rebuild) a Corvair engine?? (Would it be better for me to purchase an already rebuilt engine from you?)

2) Will it function reliably at my elevation/altitude?

3) Would I need any sort of boosting and /or is it desirable?

Flight schools here mostly fly Cessna 152s powered by O-320 150 hp engines on x country flights and usually climb up to 10,000 ft to depart through mountain passes. This is a power to wt ratio of approx 10.25 lb/hp. (I know this from fact, as I validated my commercial and private pilot's license here in one of these, with a 180lb instructor and myself @ 150lbs + 39 gal of fuel! Climb rates were low, but got us through.)

I have looked at several kits as well as plans and might go for plans because of the lower initial cost of building the plane. I also was considering the Hirth http://www.recpower.com/f302c11.htm 2-cycle 110hp engine which claims to do this at about 5600 rpm and weighing in at about 120 lbs (!!). However, it seems to be more expensive than your Corvair. Do you think that a 2 cycle engine will really output such hp?

I have looked at planes such as the Fisher Celebrity, KR2S, Ragwing Special II. What would you recommend?

My mission profile is to fly around the patch, with my kid (father of one, soon to be two!) or wife, sometimes shoot very short x country flights of about 1 hr, 100 mile range, mostly above the mentioned elevation. Temperatures year round vary between 0 and 22 degrees centigrade, very dry air, average temps between 12 and 18°C about 85% of the year. Can it be done or should I just switch to golf??

I am already involved in aviation as mg of charter flights for a TAMPA Airlines cargo. Our CEO graduated from your school but from the Arizona campus, I believe. I went to FIT in Melbourne where I got my pilot's license. Wife flies as flight attendant for AA so I want to start flying light planes again for fun and slow flight enjoyment. My best regards, and a very happy new year.

EFRAIM, Bogotá, Colombia, eotero@tampacargo.com.co

Reply from WW:

Thank you for your very nice note. Your questions are very well thought out and reasonable. One of our projects this year is to turbocharge the Corvair motor for flight. As you know, many Corvairs were turbocharged from the factory. They were the first mass produced turbo cars in the world. We are working on a motor which will use a modest 6 pounds of boost. I would estimate this to add about $1,000 to the cost of a conversion.

Anybody who can build a plane can convert a Corvair motor successfully. Do not worry about this. We've sent parts worldwide, and have never had a problem with customers being able to order directly from suppliers in the U.S. When evaluating an airplane, especially for high altitude work, the crucial feature is span loading. This is gross weight divided by wingspan in feet. Compare a couple airplanes that you know and you'll see as long as they have similar power loadings, the ones with lower span loading will fly much better in thin air. We've done a lot of flying with a density altitude near 5,000 feet and the naturally aspirated motor works well here. For local flying, a Pietenpol with a few more feet of wingspan would beat any light biplane for efficiency. You may want to consider this design.

I've only been to your country once, for a single day in Cartegena. I've met a number of very nice people from Colombia. Every one of them spoke lovingly of their home country.

Subj: Corvair to Italy

Date: 1/4/03 I WRITE YOU FROM ITALY AND I'D LIKE TO BUY AND TO KNOW HOW MUCH ARE:

1) A CORVAIR ENGINE, 3100cc 120hp, COMPLETE AND CONVERTED FOR AIRCRAFT USE, NEW AND USED.

2) A CORVAIR ENGINE TO ADAPT TO AIRCRAFT USE WITH ALL THE COMPONENTS FOR CONVERTING IT. CAN YOU HELP ME? BEST REGARDS

mitt.MARINI GABRIELE, Italy, info@vetreriagorbini.it

Reply from WW:

My main business is teaching people to build Corvair motors. I build very few complete motors. I can provide all the parts to convert the Corvair for aircraft use, and show you where to buy all the standard rebuild parts. If necessary, I can find you a good rebuildable core motor to work with. A rebuildable core with crating and shipping is approximately $1,000USD to Europe. The parts to overhaul this motor are about $1,500USD, and the components to convert it for aircraft use cost about $1,500USD additional. The 3,100cc motor is a very special conversion that requires significant machine work and very careful custom assembly. It is a much more difficult motor to build.

Subj: Corvair vs. Jabiru

Date: 1/3/03 I just came across your Web site tonight--- very interesting. I am scratch building a Zenith CH 601XL. (Earlier I had built and flew (300 hrs) a Zenair CH 701, Rotax 582.) I have been planning on installing the Jabiru 3300-- 6 cylinder- 120 hp.----- I really like the engine (except for price), but just found out one thing which I am very concerned about; IT HAS NO HEAD GASKET !! I think this is not good, as the cylinder block is machined from 4140 and the heads are machined from aluminum. Two dissimilar metals which expand at different rates. The 3300 hasn't been out very long, the 2200 has been out for a while without any problems in this area, (that I know of)---- I can't spend over $11,000 for an engine to find out that at 500 hrs the heads might warp------- I know Jabiru wants the heads torqued rather frequently.--------- your thoughts on this please----- I like the "fly-away weight" of the Jabiru vs. the Corvair engine------- I wouldn't mind the extra weight of the Corvair engine for the dollars saved --- I guess I'm asking, "can you tell me if this is a major concern, and should I strongly consider the Corvair engine for this plane"----- I had a friend who started building the CH 601HD and was planning on putting a Corvair engine in it, but gave up on the idea as he is remodeling his house.-- He tried to "sell" me on Corvair engines earlier------- In advance, thank you so much for your time- and I'll put more time into researching your info----

Fritz Gurschick, Zenith CH 601XL, Turner, Maine, klondike2@midmaine.com

Reply from WW:

Good to hear from you. Despite the fact they don't have head gaskets, Jabirus seem to be good motors. Of course, their primary problem is the arm and leg cost. The Corvair motor does typically weigh 35-40lbs. more. But the 601 is certainly capable of carrying either motor. My honest guess is that a 601 could be plans built with a Corvair motor for the same cost as buying a 3300 Jabiru. In the coming months, we'll be doing more work to develop this installation. Watch our Web site for details.

Subj: Gauges

Date: 1/2/03 What brand oil pressure and temperature senders and gauges do you recommend?

Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net

Reply from WW:

I use Autometer gauges. Go to your local performance auto shop and you will see that they offer them in both electric and mechanical and in a number of face styles.

Subj: Copper washers

Date: 1/1/03 Where do you get soft copper washers for plugs?

Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net

Reply from WW:

McMaster-Carr or any other of the industrial supply catalogs have them. My local hardware store has them in the Weatherhead line.

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