William Wynne

"The Corvair Authority"
5000-18 HWY 17 #247
Orange Park, FL 32003

A Few Words On Ignition, Avionics and Philosophy
July 14, 2006

In the past week, we've received a number of forwards from Internet discussion groups where there's been a lot of commentary on Corvair engines. We've also received a number of phone calls with builders asking questions about ignition and avionics issues. To clarify a few misundertstandings, and for the benefit of all active builders, I'll summarize a few basic points here. In general, I'd like to encourage people to take 5 minutes and call us at the hangar if you have a question about why we do something a certain way or how a particular system works. Gus or I can give you a direct answer. Also, it's the best way to find out what we use to go flying every day.


EIS stands for Engine Information System. In a nutshell, this means having a graphic display of the engine gauges done with an electronic box. Traditionally, this job is done by separate engine mechanical or electrical gauges. EISs were popularized 15 years ago on certified aircraft to monitor six-cylinder fuel injected engines in aircraft like Bonanzas. The systems we have today are far more capable, but are an outgrowth of systems from companies like Alcor.

Most people know that I'm a big fan of mechanical instruments. They're simple, cheap, reliable and well established. Some people think that this comes from no exposure to electronic instruments. Nothing could be further from the truth. Years ago, when we built Jim Rahm's Grand Champion 385mph V-8 Lancair IV-P, it used every glass cockpit EIS and EFIS available at the time. Instrumentation for the entire engine, including the injection, pressurization, ignition and engine controls, were handled by a complex group of computers, primarily, electromotive and Sierra Flight Systems hardware. In the end, the installation was the fastest, highest flying homebuilt anybody had ever seen. It won the EAA's August Rasbet Award for Engineering, and the plane changed the national discussion on AGATE (NASA's proposal for what future light planes might do) from what was possible to what now worked. Achieving this cost Jim Rahm nearly $200,000 in the panel and computers alone. It was brilliantly put together in the hangar by our co-worker and Embry Riddle graduate Bryant Cervents. We all got much more of an education on these systems than we bargained for.

EIS works and it's here to stay. Some builders like them, but they're not for everybody. Builders who are interested should evaluate their needs, learn a little bit from people flying that specific system, and choose a system that works with the Corvair engine, not in spite of it. The quality of the debate on EIS vs. traditional gauges is usually pretty low. Many of the comments are from people who have never installed or flown either system. This is not a poke at the Internet only; I've read plenty of magazine articles in which the writer parroted the sales brochure. As a golden example, the most often repeated phrase is that EIS is lighter than traditional gauges. I've yet to see this. By the time the black box, cabling and heavy electronic sending units are added, EIS is always heavier. Going directly to people who've installed and are flying these systems gets you beyond the inaccurate superficial debate which produces disinformation, well meaning or not.

Grand Rapids makes the EIS that is flying in Mark Langford's, Joe Horton's and Dan Weseman's Corvair powered planes. It obviously works. My primary complaint is that the manufacturer is not interested in developing a tachometer pickup divorced from the ignition system we use. When we were finishing our own 601, I owned two of these systems, which Grace purchased in a lot of avionics at an auction. I chose not to put it in the panel simply because of the tachometer issue. Everyone flying this unit on a Corvair will tell you that it has erratic tach operation. That's less than heartwarming when it's wired right into your ignition system. Also, the company is famous for upselling Corvair builders on 6 EGTs and 6 CHTs, ridiculous overkill for average Corvair builders.

Fortunately, a much better alternative has arrived. IK Technologies has a sterling reputation by comparison. Ralph, the company's owner, refused to sell anything to Corvair engine builders until he worked with us to specifically develop subsystems that complemented the Corvair engine. His tach pickup is by the same, simple, magnetic tooth counter we use. It's entirely divorced from the ignition system. IK offers several models and we're putting one in Rick Lindstrom's 601. IK went so far as to have special probes made that thread directly into the Corvair's pre-existing CHT holes.

On the horizon, the highly reputable Dynon company has said they're willing to develop a Corvair specific EIS unit. This is good news because they certainly produce the finest, most reasonably priced EFIS (Electronic Flight Information Systems). Rick Lindstrom's 601 will essentially have a full glass cockpit display. Gus and Rick are working together to put the finishing touches on this now. Obviously, since this is being done at our hangar, we have the capability and expertise, and I am not philosophically opposed to it. I just want builders to use the right equipment, and not cut corners on their engine in order to spend the money on the panel.

Ignition Systems

In our previous update, we covered the report of Joe Horton's engine trouble. Joe and I focused on oil systems because his Grand Rapids EIS had provided a lot of erratic oil temp and pressure information just before his flight. Turns out that his engine runs great on the ground with no changes. Joe had a long discussion on the phone with Gus about the entire event, and Gus was fairly convinced that the only plausible explanation was Joe's engine backfiring so hard that it blew the intake charge completely out of the manifold and carburetor. This was audable on the ground. The most likely causes of this are a momentarily hung up intake valve or a cross short on two of the plug wires. It was commented on the Internet by someone without a running Corvair flight engine, who's probably never even seen one run, that having dual sparkplugs might have prevented this. This type of comment reveals a lack of understanding of engine operation.

Builders are here to learn, and it would be nice if commentary was restricted to correct and tested information that has been directly applied to the Corvair.

Our Ignition System

There has been some discussion of Corvair ignition systems lately. This is what discussion groups are for. However, when someone who has never seen a Corvair engine turn a propeller, far less flown one, tells people that he's planning on building a system that's better than the one we fly every day, I have to advise people not to hold their breath.

Our system is flying on virtually all new Corvair installations that have taken to the air in the past six years. It was developed over years, and there have been zero failures of it. Anyone who at quick glance thinks there is a simple improvement possible simply has not studied the system or operated the engine. Most comments like "the motor should have a magneto" show that the commentator does not understand that magneto ignition has a very weak spark at idle and is prone to fouling plugs. I know this because I'm an A&P, and I've flown a magneto on a Corvair engine.

Many people propose getting rid of the distributor cap and rotor in favor of three dual output coils. Bad idea. If any of these three coils fail, you'll lose two cylinders plus the drag to drive them. You'll be reduced to 50% power. If you lose a coil on our system, you have 100% power still available from the other coil. This doesn't even touch on the black boxes to drive distributorless ignition or the fact that the coils have to be on the hot engine. There's a lot more to the discussion when you understand the real world installation.

I have flown dual plug heads on a Corvair. The modification is a waste of time, and certainly disturbs the combustion chamber. On a six-cylinder engine, losing one cylinder is not a big issue. One Corvair/KR pilot/builder flew the pattern at his airport on 5 cylinders with the sixth plug laying in the cowl. You cannot do this on an engine with less than 6 cylinders. Thus, dual plugs are a requirement on engines with four cylinders, but this does not apply to Corvair engines. We know this from flying the engine and running the dynomometer. Every time I read a question about dual plugs, I'm glad to teach what we know to someone who's willing to learn; when it's a statement and not a question, from a person with no experience, I'm not inclined to waste my time teaching people who don't want to learn.

Again, if you want to learn, do so from the people who are flying. KR/Corvair builder/pilot Steve Makish was the first guy to fly an electromotive ignition on a Corvair. It had no distributor cap. After a brief time, he removed this $1,500 ignition in favor of one of our standard ignitions. This same electromotive unit is installed and flying in Del Magsam's Outlaw Sonex. Del used this not because of superior performance, but as his way of dealing with standard distributor clearance issues on his motor mount. I've not heard of anyone else flying this system on a Corvair.

Builders often ask about electronic ignitions. I've explained many times that they are voltage dependent. But here is a further operational issue: Our points ignition has never been reported to make any kind of radio noise. Yet, the two people who've flown with electronic triggers replacing the points have both reported serious radio interference. While they were slow to admit that it might be their ignition, reverting to points in one of the aircraft fixed the problem instantly.

We're a week away from Brodhead and Oshkosh. I'm giving six forums on Corvair engines there. I'll be glad to cover any of this in depth. But there is a bigger picture here. Builders polarize in two camps. Most people want to use what has been flight proven to work or use this as a base from which to advance. A perfect example of this is KR/Corvair builder/pilot Mark Langford. He is capable of building or buying any ignition system he wants, yet our ignition system has flown him on more than 260 hours of adventure in barely more than a year. On the other side of the coin is the small but vocal minority who tell us of what they're going to do. Instead of justifying it by saying "It's just something I want to try," they often claim it will be an improvement over what exists and flys. More than 10 years of commercial work with the engine has taught me that these people never finish these projects, never finish their planes and never go flying. That's their own choice. My only problem with it is when they convince someone else, who could have had adventures like Mark Langford's, to trade them in for drilling another set of sparkplug holes in their heads.

Today marks five years to the day of the crash of my Pietenpol. Early this morning, Grace and I watched a finished copy of our new Flying DVD. Great stuff, expertly edited by Merrill. We've certainly come a long way in the past few years. I was sitting next to Grace, watching our movie, thinking about the date. A lot of my souvenier skin grafts and burn scars are visible in the interview sections of the DVD. I look a lot different than I did five years and one day ago. Yet all the significant changes are internal, and not the visible ones on the outside.

Builders notice that I'm more conservative than I ever was before. Readers notice that a central theme is "Go have your adventure now, don't wait." And many people notice that I have a sharp tongue for "experts" who advise untested ideas for which you're supposed to eternally delay your adventures. But this too is an external sign of my perspective on homebuilding. The most significant change in my life cannot be seen nor read; it is simply my eternal gratitude to Grace, who remained at my side before and since that day. To her and our many friends and family who have supported us, there are no words to express my gratitude.

Hangar Gang Member on the Mend

Steve Upson, member of the Hangar Gang, had open heart surgery last week. We were all surprised to hear that he was rushed to the hospital for an emergency operation, but shortly good news arrived and he's poised to make a fairly complete recovery. While we were stunned to hear he was in the hospital, in retrospect, being a 36-year chain smoker might have had something to do with it. As evidence that anything in the world can change for the better, Steve had quit smoking a week before going into the hospital. He came home pre-wired for a pacemaker. We teased him that he bought the wiring harness, but didn't get the avionics. A few days after the hospital, Steve was elated to be alive and confessed that he felt much better than he had in a long time. He's always been an upbeat person, but I'm sure he'd be cheered to hear from some of the many people who've spent time with him at past Corvair Colleges or air shows. All kidding aside, do not mention anything about politics as he is not to be excited. Send your cards and letters to Steve Upson, 2256 Turnbull Bay Road, New Smyrna Beach, FL 32168.

  • Flying Photo Scrapbook
  • Countdown To Wisconsin July 2006
  • QB 601XL At The Finish Line
  • Builder And Shipping Notes
  • Technical Oil System Notes
  • Below are several photos from Grace's collection. Enjoy. This brings the total of Corvair powered planes she's flown in to seven.

    Flying with Tom Brown, Unity, Wisc., in his Corvair powered Pietenpol NX37979 at Brodhead 2005 was quite a highlight.

    Grace has yet to fly in the plane above, but it lives at Brodhead, Wisc., where we're headed next week. This airplane is a stellar example of Bernie's handiwork in person. Any Pietenpol builder should inspect this plane closely at the Pientenpol Reunion at Brodhead July 21-22, 2006.

    Note to Tom, as well as Sue and above, Bill Knight, in Bernie Pietenpol's Last Original: We'll see you Friday.

    Our ZenVair 601. Click on the photo to view a short flyby movie.

    Grace took this photo of Dan flying the Cleanex over the St. Johns River early Sunday morning, July 9, 2006. If you click on the photo, you can see a segment of film she shot later that morning. The filming is for our upcoming hour-long DVD, which Merrill is working on for Oshkosh. Fifty percent of it is air-to-air scenes and in-flight cockpit perspectives. It's intended to be motivational and entertaining.

    DISCLAIMER: The weakest link in most aerobatic maneuvers is the pilot. Flying aerobatics requires serious training, not some hangar tips offered by friends who themselves have no serious training. We've flown aerobatics in planes as diverse as L-39s, 450hp Stearmans and S2-Bs. Grace and I had the same flight instructor, who had trained legions of pilots in aerobatics to national competition standards, and he drilled into our heads that this type of flying is only done with intense training, and no one should encourage any type of amateur or self teaching. Dan has the skills for these types of maneuvers. My Conversion Manual clearly states that the Corvair, like the vast majority of airplane engines, is not approved for aerobatics. The film is for entertainment purposes only; I don't want to start a big debate. We're all adult enough to enjoy what's presented without regarding it as blanket encouragement.

    Merrill films Whobiscat and I in front of Rick Lindstrom's Quick Build Zenair 601XL in our hangar.

    Dan Weseman's Wicked Cleanex in flight.

    Quick Build XL At The Finish Line

    As most builders know, we have Kit Planes writer Rick Lindstrom's 601XL in our hangar. He's flown out several times from California to work on the airframe. Kevin and I built him a very nice firewall forward package. Gus worked directly with Rick on the airframe and functioned as project manager. Our intention was to fly the plane to Oshkosh. It's of special interest because it's very likely to be the first Quick Build 601 to fly.

    Unfortunately, the plane will not be going for two reasons that are not in our direct control. If you're a first time homebuilder, these offer an important lesson. Rick got poor information that the FAA could process registrations quickly on a special order basis. I had never heard of this, and it turns out it isn't true. It can take several weeks to several months to process a registration, and builders should get on it if they think they're within six months of finishing their aircraft. The EAA has an excellent step-by-step information package available to members. There's no need to listen to old wives' tales about registration told by people who've never been through the process. The EAA package is outstanding and complete.

    The second issue with the plane is avionics. Rick writes a lot of avionics articles for Kit Planes, and intends to use his 601 as a flying test installation for a lot of new products. Months ago, he placed orders for glass cockpit displays for the flight and engine instruments. The engine EIS was done by Ralph at IK Technologies. This arrived in time, and is purpose engineered to mate with the Corvair's systems, including the tachometer, the achiles heel of most EIS installations on a Corvair. The IK unit will likely become the EIS of choice for Corvair builders who choose this type of instrument.

    The EFIS was to be provided by Blue Mountain Avionics. It was promised months ago, and has yet to be delivered. The Blue Mountain unit looked very promising in their Sun 'N Fun displays, but the actual product was not ready for market, Rick said. Anyone considering that type of flight instrument would obviously be much better off with the Dynon D-10.

    The lesson of real use to builders is broader than undelivered avionics: When Gus and I saw this coming, we sat down and worked backwards from Oshkosh to pick a drop dead date for flying the airplane to Wisconsin. This was based on not rushing through a safe test period. When this date passed without registration or EFIS, much to all our disappointment, we closed the door on the plane going to AirVenture Oshkosh 2006. Over the years, there have been too many stories with unhappy endings of planes rushed at the last minute to airshows. Some things in life are worth doing, even if it carries a great risk of death and this is not one of them. Builders working on their first plane should follow our lead and never rush to a deadline. Live to fly another day.

    The plan is to finish and have Gus test fly Rick's airplane two weeks after Oshkosh. After its test period, it will head to its permanent home in California's Bay Area. Although we do not professionally build airplanes in the hangar, there's a lot of positive benefit gleaned from projects like Rick's. West Coast builders will be able to see firsthand a first class example of Corvair power in action. The firewall forward package provided numerous photos for our new 601 Installation Manual. The aircraft will be featured in an upcoming series in Kit Planes magazine, which will bring more momentum to our Corvair movement. When Rick's plane flys West, we'd like to have another 601XL project replace it in the shop. If you're interested, call Gus on the shop line, or speak with him in person at Oshkosh. He'll be in the Zenith booth when he's not flying showcases.

    While some people will certainly point out that over the years there have been oodles of delays of our shipment of parts to builders, I still feel comfortable criticizing Blue Mountain, because they were told that it was needed for Oshkosh. Although I've been told by a few builders that a delayed part from us is the only thing holding them up from flying around the world, I'm yet to see any real, fair, concrete evidence of it. Certainly nothing that would weigh in against how much we've helped people get closer to flying. By the way, the record for going on the Internet and complaining that a part from my shop is holding up your project belongs to a builder out West who stated that his spinner bulkhead, on order for two months, was the only thing keeping his plane from flying. I delivered it more than 2 1/2 years ago, and the plane's yet to see daylight under the tires.

    Here's a top view of Rick's engine last week. The oil cooler is a Niagara 2002. We use this as the ultra heavy duty installation. I have put these on our own 601, Dave's Wagabond and Phil Maxson's 601. They're not a requirement, but are a nice option. We'll have more details on this in our 601 Corvair Installation Manual. By the way, Phil will be flying his plane to Oshkosh.

    The most important thing in this photo is the drill priming the engine through the distributor hole. I've shown numerous photos of this, and reminded people many times that all engines must be primed before they're run. One of the engines we built in 2004 was ordered without a starter because the builder opted to use a reverse rotated rear starter. This meant we could not run the engine at the shop. To ensure it was primed before it was run, we actually delivered the engine with a priming tool in place of the distributor. This engine was run, but not flown, in 2005. When the builder removed the crank for nitriding, he called to complain to me about scratches on the bearings. My first question to him was, "Did you use the priming tool?" Do you have a guess what his answer was? He answered "No."

    I ran the above setup on Rick's engine for 1 1/2 hours. During this time, I moved the position of the crank every few minutes. This circulated all the oil through the engine, including the filter, many, many times. You cannot hurt an engine by priming it too much or changing the oil too often or running too high quality of a filter or oil.

    Builder And Shipping Notes

    We are working hard to knock off all the back orders before Oshkosh. Grace and I will be bringing a lot of parts to Brodhead and AirVenture. If there's something specific you'd like, give us a call at the hangar, (386) 478-0396. We want to tell everyone that we'll be at Brodhead and AirVenture July 20 to 30. Following AirVenture, Grace and I are going to be on the road for two weeks. Gus will be flying to his parents' place in Michigan for 10 days or so. There will be a skeleton crew on hand at the shop, but we are not planning on conducting regular business operations for the first two weeks in August.

    Almost every year, someone calls our shop number every day the week we're at the largest airshow in the world and promptly reports to the Internet that no one's answering and we're likely out of business. While I'd like to say that this used to make me livid, but now I've matured and accept this as part of being in business, the truth is that it makes me just as angry as it ever did. I'm as immune to anger management training as John Monnett. So no, we're not out of business after 12 years, we're all at Brodhead and Oshkosh like we always are this time of year and hope to see you there.

    Technical Oil System Notes

    One characteristic difference between my work with Corvair engines and most businesses whose primary focus is the sale of engines, not the education of builders, is that we will openly discuss builders' difficulties and operational issues here. Our handling of the crankshaft issues is the primary example of this. Here's another example:

    On Sunday, after the filming, I got a call from Corvair/KR-2S builder/pilot Joe Horton of Pennsylvania. He explained that he'd had a power failure at 400' after takeoff. Showing excellent judgement, and sharp knowledge of his aircraft's parameters, he stayed focused on flying the plane and executed a smooth 180 degree turn to the runway with plenty of room to spare. The airplane was undamaged. (In my own accident years ago, the pilot got distracted by trying to restart the airplane at 600' and turned what probably would have been a harmless forced landing in a long, smooth field into a near fatal accident.)

    When we talked, Joe hadn't had a chance to look at the engine closely other than to verify that the crank was not broken. We discussed a number of indications leading up to the problem, and Joe was going to check them out and give me a call. Joe's plane has 81 hours on it that have been trouble free. His 3,100cc engine has a rear starter on it and a unique oil system. We discussed a number of possibilities, most of which will likely be eliminated as the cause of the engine stoppage. But my observations here on oil systems are worth noting for all Corvair builders.

    Joe's airplane has a remote mounted filter and cooler. They are rigged in series in what I refer to as a three-hose system. On his plane, the oil exits the engine and returns to it where the original oil filter housing was. Based on testing I have done, I recommend against running a system configured this way. Although numerous people saw my Pietenpol running with a three-hose series system as long ago as 1999, there was one important difference: The oil lines on my plane entered and exited the engine where the stock oil cooler was. When it's configured at that location, the engine is protected by the stock oil cooler bypass. A system configured from the oil filter location does not have a functioning bypass for the cooler. Even if one is in the filter itself, the series orientation means that all the oil pumped, no matter what temperature or viscosity it is, must go through the cooler.

    When the engine is first started, even if it's relatively warm outside, a stock Corvair engine will bypass the cooler for several minutes. If it's 30F outside, it will bypass the cooler for more than 10 minutes. It's designed to do this by opening the bypass with only a 7 pound reduction in the oil pressure. The cooler itself is designed to promote this by having a lot of drag internally on high viscosity oil to make the bypass work and let the engine heat up the oil quickly. When run without a bypass, the cooler is capable of putting far more than 7 pounds of pressure reduction on the system, even with thin oil.

    Joe told me that his pressure gauge in the system came before the cooler. When the engine's heating up, this provides no indication of what the actual pressure in the bearings is. At the very least, the system needs to have the pressure measured after the cooler. I'm certain that builders would be alarmed to see the pressure reduction. The Corvair engine's oil system is not difficult to understand if you study it, but many people have made incorrect assumptions about its operation, and my shop is the only place where I've seen real testing on flow rates at different temperatures, drag reduction and pump efficiencies done.

    If there is a flaw in the oil system that starves the engine for oil, the first thing that will go is the number 5 or 6 rod bearing. Being a plans built product, the Corvair engine is subject to enormous variations. I always want to encourage people to copy something that we've flight proven, or at least discuss the system with us. It could save you a whole lot of trouble.

    Note To Anonymous Admirer In North Carolina

    Thank you very much for your present. Grace greatly appreciates it.

    Now At The Hangar

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    OSH, Illinois and SAA June 13, 2005

    At The Hangar June 13, 2005 Part II

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