100 HP Corvair, Tim Hansen , Persistence Pays


Ten years ago, at Corvair College #9, a young man showed up after a very long trip: He had taken a Greyhound bus from Ohio to Edgewater, Florida He was only able to stay at the College for 24 hours before he had to catch the return bus. He was a college student, he had done a lot of research, and he asked good questions. Serious builders were impressed with his attitude, and the commitment to have his seat at the table of experimental aviation.


Tonight, nearly ten years later, despite all the obstacles that life can serve, Tim’s carefully built 100 HP Corvair, a product of his own hands and mind, fired up for a perfect test run. The running engine is destined for his homebuilt, but the achievement isn’t the powerplant.  It is in Tim’s attitude to really learn and understand engines, to build an excellent example, to be persistent when others are not. The reward is internal, it cannot be diminished, lost, spent nor taken away. He owns it, period.


In most other aviation settings, people’s value is judged by the thickness of their wallet. That attitude is abhorrent to me. Conversely, in the Corvair movement, the value of an individual is judged solely on his personal commitment to the original EAA motto “Learn, Build and Fly.” In the pantheon of tradition builders whom I have met in two-and-a-half decades in experimental aviation, Tim Hansen holds a very special place, as he is the personification of my Golden Rule of homebuilding: Persistence Pays.




Above, Tim’s engine on the run stand on the ramp in front of our hangar. After Corvair College #31, out of respect for his personal commitment, Grace extended a rare invitation to our home, to have Tim finish and test run his engine. The weekend was the only open date in Tim’s work schedule. He drove down from Ohio, worked for a day, and had it on the stand by 9 PM Saturday.




Congratulations to Tim, just after it fired up. A memorable moment In The Arena. The engine is a 2,700 cc Corvair with a Weseman Gen II 5th bearing and all of our gold systems and parts. Tim was on a budget, but he long ago set his personal standard, that his own engine would be first class. He was focused on getting everything he could from the process, not doing it as cheaply as possible.




Above Tim with his engine after the run. The sign he holds tell the story of a man who would not be dissuaded from his goal.




Read closely: Tim traveled  8,787 miles, 1,821 of them by bus, to learn the skills, processes, techniques and understanding so that he may rightfully use the title “Motorhead.” In the decade since his first arrival at College #9, Tim also earned a private pilot rating and had built a substantial amount of hours becoming an Airman. The achievements were gained against life’s adversities: In the early years, a cycle accident put Tim in a wheelchair for six months and brought a mountain of uncovered medical expense. Most people would have seen these as acceptable reasons for walking away from the dream of flight, but Tim Hansen isn’t “most people” –  he has his own standards for himself.




Tim’s engine puts down a night break in run in, outside the hangar in our front yard. Grace keeps the Christmas lights up 365 nights a year. By coincidence, on the left, well known 601XL/Corvair builder and Pilot Phil Maxson,  (Phil Maxson goes to 3,000 cc for his 601XL )  was in the area. He was on hand to welcome Tim into the ranks of successful Corvair builders.  Phil stayed to see the engine run, because he is a member of our community of builders, a group defined by their traditional take on “Learn, Build and Fly.”  Most experimental engines are simple consumer products with nothing to unite their owners except the amount of money they spent. For builders looking for more from their hours in aviation, we have a setting where craftsmanship, commitment and camaraderie all retain  their traditional value as the primary currency of aviators.




Grace worked many years to become an aviator herself, and she has a special understanding for any individual who sets themselves to the task, keeps their standards high, and refuses to quit. Above, Grace shares Tim’s hour of victory.


After a few photos, we threw some steaks on the grill, and had a late dinner, spending the time remembering events from the past decade, and speaking of good things to come. As I write this, it is now 3 am, and everyone has long gone to bed. The morning will bring a long drive back to Ohio for Tim, and a full day of College #33 prep for us. Yet I am kept awake by thoughts of having just been present at a major milestone in the path of another aviator. Next week, someone will ask what is the reward of our work with Corvairs, and I will simply refer them to this story.


“At any real level, flying is not a sport, a hobby, a pastime nor entertainment. It is An Endeavor, worthy of every hour of your life you invest; Those who dabble in it find only high cost, poor reward and serious risk. They are approaching it as consumers. Conversely, for those who devote their best efforts and their serious commitment, the rewards are without compare.”  -ww.

Night Engine Run, December 20, 2014


Above, the 3,000 cc Corvair built for Zenith builder Thomas Fernandez running on the stand last night in front of our house. The Christmas Lights are on the trees in front of our porch. Grace likes them all year long.


I have often thought I should have logged how many engine have run on this stand since I built it, but I never have. The best guess I have is about 400. The stand is chained down to a 700 pound concrete block we cast into the front yard years ago. For a solid attach point I cast an old Corvair crank standing on end in it. All that is visible is the nub the harmonic balancer bolted on to. The chain is bolted to the  1/2″-20 threads that balancer bolt threaded into.



Above, the set up for a night run: Our neighbor, Corvair/Panther builder Paul Salter mans the lights and helped me set up for the run. He has been to many Colleges and has been with SPA/Panther at Oshkosh the last few years. His hangar is 500′ up the runway from us. Grace’s Taylorcraft sits on our front lawn. It was about 60F in northern FL last night. In the winter, the low temp here has no typical number, it is just as likely to be 30F as 60F on any given night.


Click on the image above to view a movie of our Saturday Night Live Engine Run. There are things that you can see at night that are not visible during the day: Watch the tape closely, and look at the bottom of the exhaust pipe on the far side of the engine. If you look real close you can see a small flame appear intermittently. Although the engine was running near perfect to the ear, and all indications were 100% normal, this condition was caused by the test stand’s #2 spark plug wire having a slight break in it, allowing an intermittent miss, sending an occasional shot of unburned air and fuel into the exhaust pipe. This condition is absolutely invisible during the day.


The test stand has it’s own plug wire set, and they are about 10 years old and they have been taken on and off hundreds of times. With the wire replaced, this issue disappeared. It didn’t come as a surprise, it did this also on the last engine we ran at Corvair College #31 in November. To see what the stand is equipped with and what you need to run your engine at a college, read: Running an Engine at a College, required items. #2 and Running an Engine at a College, required items. #1

One more look at the engine running. It ran for about 30 minutes, the length of time we use to break in the cam. This engine is equipped with one of our cam kits: 1100-WW Camshaft Group. The break in was with 4.5 quarts of Rotella and 6 oz of ZDDP. Read Notes on Corvair flight engine oils. Another hour of break in, and the engine is crated and shipped. It will not make it for Christmas, but it will be a welcome milestone on the journey to many aviation adventures.-ww.

3,000 cc Corvair Engine Details


Here are several photos showing some details of the assembly of a 3,000 cc Corvair engine in the shop over the last week. The engine is going to a Zenith 750 builder is Colorado. It is also the same engine shown running in the next story.



Above, Rear quarter view of the engine. It is a 3,000 cc engine with a GM 8409 crank prepped by the Weseman’s with one of their Gen.II  5th bearings. Visible in the photo is our #2000-HV rear oil cases, and the cylinders and pistions from our 3,000 cc Kit.


When I assemble an engine it first starts laying on it’s side in a case stand, then I put it in a Roy’s Garage rotating stand (shown) and then I put it on a nose stand, and then it is transferred to the run stand. Building at home, you could start just with a Roy stand and do the test run on your airframe. Everyone has an approach they like to use, but at the colleges I teach builder to mimic the four step process I do in the shop. There are faster ways, but the goal is not to get the motor done, it is to do an excellent job, understand what you are doing and do accurate work. I do not rush assembling engines, quick is not a goal.


One of the things I have long noted is that if the engine is very firmly bolted to the bench, you can notice very small changes in rotating drag build up, etc. When working on things I like the part to be held firmly, the tools to be quality, and the lighting to be very good. To some people, just ‘having’ a plane is the goal, and building parts of it is some type of penitence. I also want the finished product, buy my goal is very different, the process matters to me. The destination is important, but I don’t try to get there by short cuts. I want to take the journey and enjoy it in style. As with most other things in life, people who obsessively want to find a short cut often find the longest and most expensive path, full of frustration, if they get there at all.



Above, front quarter view.  #2501 Short Gold hub, #2408 ring gear and the inner part of the #2901 front alternator bracket. Behind is the #3000 Weseman billet 5th bearing. You can see the dipstic tube is already in. Read: All about Dipsticks, Part #2206


On the studs are the cylinder hold down tubes that clamp each cylinder down as you assemble the motor. Without them, as you turned the crank to put each new cylinder on, it would dislodge the previous cylinders. Mine are steel, but even simple thick wall PVC will do the job.  3,000 cc motors do not use base gaskets. The cylinders are sealed with either Permatex Ultra grey #82194 or Loctite 515 #51531. You can find either of these at any auto parts store.


Without fail, at every college, a number of builders will show up with chemicals, sealants and particularly Loctite products that are not the correct ones. Be advised: when I point this out, the wrong response is to say “This is the same stuff”. I have had at least 20 different things presented to me with the claim they are “the same” as Loctite 620. They are not. There is a very important lesson here. If someone is not willing to use the right material, they should not build any engine, not just a Corvair. If they don’t like following specific instructions, perhaps it is time to re-think even getting into aviation.


“It’s is the same” is the indication that the person was unwilling to go to a second auto parts store 5 miles away to find the specified material. When I just drove 1,000 miles to get to the college, I am not sympathetic. This goes on with every part on the engine, including spark plugs. Please read this: A Tale of Two Spark Plugs…… “Guy A” in the story has a Phd in Aerospace engineering, 6,000 hours and has been an expert witness in trials that passed judgment on the mechanical decisions of others. You can be pretty smart, but success in aviation has more to do with paying attention to details, even if these details were developed by a long haired, foul mouthed, troglodyte aircraft mechanic in Florida with a two digit IQ.



Above, a look at a perfectly rebuilt head. In our catalog and numbering system, heads are Group #1500. The individual numbers in the group run from #1501 to #1509, but a complete pair of heads comes with all the parts installed, ready to bolt on. These specific heads are from our Jacksonville FL. source that Dan and I have been working with for the last 6 months. It was a long developmental process to make sure that we can get the highest quality head work done, but we are there now. In our catalog A complete pair of heads is part #1500-ww. In the photo, these heads have “Timesert” spark plug inserts.



Above, a look inside. Corvair Connecting rods are #1303 in our numbering system. Most of the engines we build have rebuilt GM connecting rods. However it is a popular option to use these billet rods from The Wesemans at SPA. You can read about them at this link: https://flywithspa.com/product/corvair-billet-connecting-rods/. When a builder buys a 3,000 cc kit from us, it is $2,200. This includes the machine work, the cylinders, pistons, rings and rebuilt GM rods. For builders who wish to substitute SPA rods, we lower the kit price by $300. The black X’s on the rods are my notes that they have been final torqued.



Above, A top view. The Gold cover is part #2405. Note that 4 of the bolt holes are not filled. These are where the  #2402 front starter brackets bolt up next. Under the cover is the #2406 gasket, which has a thin film of Permatex Ultra Grey on both sides of it. Like all our other parts it has directions that explain this. The directions are alo on our website products page. Lesson#2: When a builder at a College is installing the top cover, and coating it with something else, and I can see on his bench the instructions that came with his top cover still sealed in the bag on his bench, He is going to get a friendly but firm reminder from me that I hold colleges to teach people how to build Corvair correctly. I do not hold Colleges to help people get their engines done. Yes, that does happen, but it only happens when builders are doing it correctly and learning. If the instructions are in the bag on the bench that condition is not being met.


 When even looking at pictures of engine, I can see details like what type of sealant was used on gaskets. It tells me a lot about what a builders mind set was when he was putting his engine together. I will occasionally remind people that I made the same amount of money selling a part that was installed wrong as I did selling the one that was installed perfectly. The only person who the guy in a rush cheated was himself. -ww.


12 Cylinders / 6.0L of Corvair Power for JAG-2 run at CC#31


If you read this site regularly, you have already heard of Jim and Ginger Tomaszewski’s twin project, the JAG-2. They finished both engines for it at Corvair College#31, and we got both of them on the run stand on Sunday for 30 minutes each. They ran flawlessly.


You can see photos of the nearly done plane at this link: New Photos of JAG-2, a Corvair powered twin. and you can read a longer story on the development of the plane in Jim’s words at this link: JAG-2, Corvair Powered Twin, Jim Tomaszewski, N.Y.


Without fail, when the topic of this plane comes up, someone will chime in to say that flying a twin requires a special rating and twins have a poor safety record when flown by amateurs with the wealth to buy them but not the skill to operate them. These statements are true, but they do not apply to Jim.


He is a low-time single engine pilot with 500 hours, but he is a high time multi pilot with more than 15,000 hours in planes with more than one engine. You would think people might pick up on this as Jim’s Email address is ‘DC-8Jim’, but they often do not. Much of Jim’s time is global corporate flying, often to very challenging destinations. Ask any honest ATP and they will tell you that very few airline destinations require the skill of a night landing in a corporate jet at Aspen Colorado.



Above, both engines on the bench. These are first class 3,000 cc Corvairs. They have Weseman Billet cranks (https://flywithspa.com/product-category/corvair/) and all our Gold system parts. (these were painted by Jim to suit his taste).  Note that both engines are equipped with our new Ultra light weight Starter assemblies, part number 2400L. These engines are essentially clones of the one on Dan Wesemans Panther, (although most pictures show the Panther engine with our standard starter, it has been flying on a 2400L since the spring.) For a look at the logic behind that engine, read this story:Why Not the Panther engine?



Above, both engine in process with Jim and Ginger on the right. They ordered  #2000HV cases before the event and picked them up in person, they took only a 30 minutes each to install. The engine oil fillers are on the top covers because the narrow twin cowls do not have the space on the sides like single engine cowls do. Both engines have group #2800 oil systems and rear alternators.


IMG_1730 IMG_1729

 Above, two more photos of Jim and Ginger with the engines.


 Above, the second engine runs at the college. Jim said his time line is to fly the twin back to Barnwell next year, fully flight tested and proven. A great number of Corvair builders will rightfully hail him on that day, as a champion of homebuilding and as a builder who was willing to put in the had work to do something extraordinary in aviation.-ww.




Special Note to RV Builders: The section of the Van’s Airforce discussion group that showed just a few pictures and short descriptions of this aircraft generated thousands of hits before their list moderator banned the photos and deleted references to it, and put up his own negative comment. That list is operated as a commercial venture by Doug Reeves, a controversial personality who promotes a very conformist model of homebuilding and flying. He will delete your posts if they reference things he dislikes, often as simple as making a low pass. 


In a single week, the tracking on our site showed that 220 RV builders on that site followed a link to come here and read my story 2,500 words about levels of aircraft finish… Reeves also deleted all of the links to that story to block RV builders from even referencing it. It was deemed too controversial because it included the single sentence “We were not the ones who decided that regular looking people and the planes they built were not cool enough to be on the cover of their own membership magazine. That one is on the Editors and the management of the EAA…” To my perspective, Reeves is a throwback to the type of aviation magazine editors of the 1980s and ’90s who worked to make sure only people they “approved of’” felt welcome in experimental aviation. RV builders are often unfairly characterized as uncreative conformists. Reeves’ actions unfortunately reinforce this stereotype. RV builders with open minds are welcome to come here and directly read unfiltered ideas.  -ww



Complete Engines for Sale

WW Corvair Engines For Sale

Completely Rebuilt And Test Run At Our Shop

 Over the years, we’ve built more than 100 high quality production engines for builders who opted to buy the  finished product from us. As a policy, every one  of these engines are test run and broken in on our run stand. A review of our  FlyCorvair.com and FlyCorvair.net Web sites will show photos of dozens of engines we’ve built that are now flying. Our great experience with Corvairs, our use of only the highest quality parts and the test runs have given us a spotless track record with production engines. This record makes it easy to stand behind engines we’ve built. These engines are fully remanufactured, and converted for aircraft duty. People who have selected our engines, installed them on their aircraft and operated them as we recommend have had to do no work other than regular oil changes and spark plug replacement at 200 hour intervals. The TBO on the engines is 1,500 hrs.

Many people who have selected a production engine still opt to attend the Colleges to get to know the inside of their Corvair engine. I  encourage this because education has always been our primary work, and an educated Corvair pilot will be a better owner and operator.

We have three different displacements/HP ratings available. Below we have three examples, one of each engine. If you have further questions about your application, feel free to write or call.

All of the engines we build are completely overhauled and modified with state of the art components made in the USA. Every engine has a forged crank that has been Magnafluxed, stress relieved, ground, balanced, nitrided, polished and balanced. Our engines are built on the readily available Weseman 5th bearing. We have built a number of other engines using our own bearing and the one from Roy’s, and we will gladly speak with anyone about using either of these bearings.  Our bearing or Roy’s add $1,000 to the price of an engine. There are other options like a Weseman billet crank, which adds about $1,500 to the cost of an engine. We are glad to include any proven option

The heads we use on our engines come from Mark at FalconMachine.net. I have been working with him for more than 10 years. His background as a Spartan-trained A&P mechanic, and a 32-year history of working with Corvairs led him to being the number one man in the world on cylinder heads for Corvair flight engines. He has worked directly with to fine tune every detail of head rebuilding and precision machining defines what state of the art is. Most of the successful flying Corvair powered planes today are utilizing his heads. Over the years he has produced more than 170 pairs of heads, and they enjoy a perfect track record.

Additionally, all of the engines have forged pistons, and the 2,850 and 3,000 have new cylinders.  (The 2700 cylinders are re-bored GM originals.) They have forged rods with ARP bolts, harmonic balancers and  high volume oil pumps. Each engine has dual ignition and  electric start with a 22 amp alternator. The engines have  our gold oil system and the builder’s choice of billet or welded oil pan.  (Heavy duty oil cooling systems are a popular $600 option.) The only major component not included is the carburetor.  While any of the engines can be used on airframes as different as a KR-2S to a Zenith 750, the carb must be a good  match for the airframe. For example, aircraft with low wings and fuel pumps require MA-3 or Ellison carbs, while  gravity feed airframes can use a wide array of carbs, including the affordable Stromberg. The Corvair has flown on  more than 15 different carbs, and we will be glad to assist you in choosing the correct one for your airframe.


Above, an engine we assembled for a builder. The engine is on our run stand outside our hangar. Every engine we assemble is test run and broken in on our run stand. The engine’s performance is carefully evaluated against dozens of others we have built. This test run allows even fine details such as the hot idle regulated oil pressure to be preset before the engine is delivered.

Above, a picture of a 3,000 cc dished “Dual Fuel” forged piston. These are made in the USA to our exact specification. These pistons are the heart of 2,850 and 3,000 cc Corvair engines. They allow these engines to run equally well on 100LL or high grade automotive fuel. The design maintains a very tight quench area to the head while keeping a moderate static compression ratio. Many alternative engines have electronic elements and valve designs that are not compatible with the high levels of lead in aircraft fuel. Others have excessive compression ratios that make operation on fuel below 100 octane a serious detonation risk.  No such issues exist with our Corvair conversions. When Corvairs were built, all automotive fuel was leaded; in the past 30 years they have proven to operate on unleaded fuel. Our 2,850 and 3,000 cc engines have these special pistons to maintain the ability of operating on either fuel. Corvair engines are not bothered by ethanol in fuel. The head in the picture was remanufactured by Mark at Falcon Machine.

Above, a look inside an engine during assembly in our hangar. As a direct drive, horizontally opposed, air cooled engine fed with a single carb, the Corvair engine is a model of simplicity and reliability. It has been powering experimental aircraft since 1960, and we have been continuously working with them since 1989. Many people new to homebuilding are taught by magazines to look at things which are “new and exciting.” All of my work has been aimed at testing and developing proven methods and systems that builders can count on. “Old And Flight Proven” is the opposite end of the spectrum. It is my personal philosophy that many more homebuilders have been served by “Old And Proven.” Builders who understand this fundamental truth of aviation naturally gravitate to our work with the Corvair.


Below are three example of assembled engines we offer:

2,700 cc Engine, Weseman 5th bearing, 100hp continuous, 225 pounds, $9,750

Above, Zenith 650 builder Becky Shipman and myself observe a break in run of her 2,700 cc engine at  Corvair College #22 in Texas. This engine was assembled in my hangar before the event.  Attending the event gave Becky a good look at what was inside her powerplant, and familiarized her with the  operational procedures. We encourage builders purchasing an assembled engine from us to attend  our Colleges. Read the whole story on Becky’s engine at this link: Shipman Engine at CC#22


2,850 cc Engine, Weseman 5th bearing, 100hp continuous, 225 pounds, $10,750

Above, Roger Grable and his grandson Graham stand by their new 2,850 cc engine during its break-in run at  Corvair College #23 in Florida. I assembled the engine in our hangar before the event.  Roger and his wife had attened CC#22 four months earlier, and had elected to have us build an  engine for his fast moving project. We have a fairly short lead time on complete engines, and Roger drove to CC#23 and  took delivery on the engine. There is an Internet based rumor that claims that we do not build engines or they take a  long time to get. The three real world examples of engines we have built this year offer a reality check on such  stories. To read the complete story on Roger’s Zenith 750 engine, follow this link: Corvair College #23 – 2850cc Engine, Roger Grable, CH-750 Builder


3,000 cc Engine, Weseman 5th bearing, 120hp continuous, 218 pounds, $11,750

Above, a 3,000 cc engine we built for the Zenith 750 project of Lary Hatfield and sons. We met Lary at the  Zenith open house at the factory, which he followed up by attending Corvair College #21.  In person, Lary is an easygoing guy with a laid back approach on the surface. When you learn more about his experience, you understand that he and his sons have worked very hard and had outstanding success in very competitive levels of automotive racing. They are equally accomplished in aviation. They have worked hard enough to afford to put any piston engine they choose on the front of their Zenith, yet they selected a Corvair after careful consideration. I take it as a compliment to our work with the Corvair when men of their mechanical experience carefully evaluate and choose Corvair power. A longer story on their project can be found on http://www.FlyCorvair.net at:


A long time ago, I realized that a builder buying an engine from us was really purchasing more than a powerplant. He is making an investment in our judgement. Builders are looking for a good value in an engine, not the cheapest price. Airplanes are a lot of fun, but airworthiness is serious business. I appreciate this and cut no corners on engines that we build.

The single most important thing a builder can understand about our engine program is very simple, but often overlooked. Completed engines are a small portion of our efforts with the Corvair. Most of our work goes into teaching builders how to build their own engine and supplying the conversion and installation components. Carefully and correctly built engines actually are not a particularly lucrative part of our operation. We build them for several reasons beyond the bottom line: They are excellent demonstrators of the potential of the Corvair as we convert it; They provide a blueprint for builders assembling their own engines; and we often use them as assembly or test run demonstrators at Colleges. To serve the above purposes, they must be carefully built of the finest parts. Moral issues aside, there is absolutely no incentive in any form for me to cut any corner on any engine. A single issue in the field would undo the larger purpose of building the engines in the first place. We have been here for a long time, and every time I turn a wrench in the shop I am aware that I will be doing this in another 20 years also. There is no short cut to long term success.

Conversely, any company that makes its living just on complete engines, especially if it is an LLC, has an enormous incentive to cut corners on every part inside their engines. The only way they make money is by charging more, lowering their cost, or both. In tight economic times, price has a ceiling, so lowering the cost and cutting a few corners is the way to go. They can do the math, and every dollar they will ever make is based solely on this differential. They know that 9 out of 10 engines they sell will not go flying in the next 3 years. Organized as an LLC, they can walk away from the business without any financial obligation to their customers. If you’re new to aviation this may sound far fetched, but it is actually how the majority of alternative engine companies have been started, operated and dissolved in the past 20 years.

Our income is not based on the finite possibilities of the cost versus price equation. Our potential is directly related to the reputation that the Corvair enjoys as an affordable and reliable powerplant. The engines we assemble for builders enhance this reputation by being excellent examples of the conversion. Even the most cynical person who is yet to know my personal morality against poor products in experimental aviation can understand how we are only incentivized to build excellent engines.

If you are a builder interested in discussing an assembled Corvair for your project, let me suggest the following; take the time to read the stories in the links above. Also get a look at our main reference page, FlyCorvair.com. At the bottom of the main page is a search box that allows you to find any subject. The site has well over 1,000 pages of text. You don’t have to read it all (some of it is historical or dated), but you will find an excellent introduction to the engine. Then, write me with any questions you may have. Please include your phone number, and a good time to call you. We keep all the information confidential, but I find the phone a much faster way to cover builders’ questions. Understand that we get many emails every week asking about buying an engine. Some are scams, others are from 15-year-olds, some are from people asking if the engine will power a Lancair IVP, others asking what type of antifreeze goes in the engine. There may be one real builder in the group. In my experience, the real builder appreciates 30 minutes on the phone, and all the others want to have long protracted email exchanges. Set yourself apart, send your phone number.

As all of our engines are hand-built, I’ll be glad to discuss individual custom touches for builders ordering engines. A confirmed engine order requires a 50% deposit, and the balance must be paid before the engine is shipped. Crating and shipping are a modest, but additional cost. You can place your engine order with a check payable to William Wynne, 5000-18 US HWY 17 #247, Orange Park, FL 32003, or by credit card via PayPal to WilliamTCA@aol.com

Thank you.

William Wynne http://www.FlyCorvair.com http://www.FlyCorvair.net

Corvair power for Panther and Sonex reference page


I have collected in this one story a complete overview of the Corvair power option for builders considering or working on the SPA Panther kit aircraft and Sonex airframes.  These two aircraft are grouped together because both of these installations were developed by Dan Weseman, (SPA is his company) who offers airframe components that seamlessly work with our Corvair engine components.

Builders who are already working on, or flying a Corvair will be familiar with much of this material, but I bring it all together here for Panther and Sonex builders who are not yet familiar with the Corvair. If you would like to start with a simple three page spec sheet on the engine, read this link first: Basic Corvair information



Above, Oshkosh 2013: Dan Weseman selected the Corvair as the engine for his Panther prototype. He did not make the choice lightly. He has hundreds of hours of Corvair flight experience, developed the highly successful “Cleanex” (Corvair powered Sonex airframe combo), manufactures a number of Corvair flight products like 5th bearings and Billet Cranks, and is well known and respected in the Corvair movement. In 2009, we awarded him The Cherry Grove Trophy , as Corvair Aviator of the year.


The Panther:

The Panther was designed to take a very broad variety of engines from large VW’s to 160hp Lycomings. Dan has extensive flight and ownership experience with most Common light aircraft engines, but he selected the Corvair as his chosen introduction engine for the Panther for a number of good reasons. Not only is the engine powerful, smooth and reliable, it also supports Dan’s mission of keeping the plane affordable for rank and file homebuilders.

No rational man introduces a new aircraft with an engine he must make excuses for. Dan knew the Corvair would not disappoint the industry people and media who would be invited to fly the prototype. The most common thing said by highly experienced builders and designers who see the Panther perform 170 mph low passes, 1600 fpm climbs and aerobatic maneuvers is “I can’t believe that is powered by a car engine.” The Corvair in this installation has the performance to change aviators perspectives on the capabilities of auto conversion engines. Paul Dye, Editor in chief of Kitplanes, came to Florida to fly the plane. Very impressed, on the engine he commented that it functioned just like a Lycoming, just much smoother.

Above, Paul Dye, editor of Kitplanes returns from his flight in the Panther.


If you would like to see a visual example of how well the plane performs with a Corvair, get a look at this link:



You can read all the detailed information on the SPA website at this link:




If would like to read about how this airframe flight tested Billet Cranks Made In The USA, click on the story title.


Above, enroute to Corvair College #16, ‘Son of Cleanex’ builder/pilot Chris Smith shot this photo of Dan Weseman off his wing as they flew up from Florida in loose formation. Although it is not for everyone, the Corvair when installed correctly in the Sonex airframe provided a high performance engine that is essentially immune to overheating issues.


The Sonex:


The Sonex is an outstanding light aircraft designed by John Monnett. It, and the Y-tailed Waiex have sold hundreds of aircraft kits. For 10 years,the Sonex factory approved only three engines for the airframe: the 2,180cc VW, and the 80 hp and 120 hp Jabbirus. The factory position firmly asserted that for an aircraft to be a Sonex, it must have one of these three engines. We’re personal friends with the Monnett family, and to respect their wishes, I carefully referred to the combination as a Corvair powered Sonex airframe, or Dan’s development as a “Cleanex” (a name Dan was slow to grow fond of.) I picked the name because Dan’s plane was a very clean build, that most people were stunned to find out was plans built, not a kit.

Recently in an EAA Webinar, Jeremy Monnett announced an company policy change of sorts, and stated that they were going to adopt a much softer line on this, comparative to other experimental airframe companies. Even with this change, we still refer to any Corvair powered Sonex or Waiex airframe that is adapted to Dan’s installation and uses our engine parts as a “Cleanex.” Like 1950’s Frankenstein movie sequels, a number of builders chose names for their planes like “Son of Cleanex”, “Bride of Cleanex” and “Daughter of Cleanex.”

Dan’s plane is an outstanding performer. I flew in it with Dan, on an 85 degree day off  our 2,400′  tree-lined grass airstrip in Florida. At the time our combined weight was 430 pounds and we had 12 gallons in the tank. If anyone tells you that VW’s are as powerful as Corvairs, they simply have never seen a Corvair in action. Dan’s plane could do an honest 155 mph on 5 gallon’s an hour, and top out above 175 mph.  Dan demonstrated many times that he could run the plane flat out at top speed for more than 40 minutes without the engine running hot.

I offered an opinionated Jabaru 3300 pilot $1,000 cash if his plane could beat Dan’s over a 100 mile course.  He didn’t take me up on it for a simple reason: he was afraid if he ran his $18K engine that hard for 40 minutes he would cook it. The speed would have required running the Jabaru 500 rpm over its factory approved continuous rating. GM designed the Corvair with a 5,500 rpm redline and a 575F CHT limit. Even at top speed, Dan’s Corvair is only using a fraction of these ratings. The is the key element in the Corvair’s reputation as a very robust power plant. It is approximately 25 pounds heavier than a 3300; much of the weight difference is in the Corvair’s cylinder heads which are literally covered in deep cooling fins.

If you would like to see for 120hp Corvairs taking off in succession, check out this link. Dan’s and Chris Smiths aircraft are two of the planes leaving Corvair College #16:




Above, Dan and his Cleanex in front of my hangar at Corvair College #8. (2004) Until his airplane was done and flying, we kept Dan’s identity a mystery. At the time, a few people who saw this photo made jokes about the “Builder Protection Program” with a nod toward John Monnett’s allegededly sharp temper about people putting other engines in his designs. In reality, Dan is friends with the Monnetts.  The Cigarette was part of the ploy, Dan has never been a smoker. Today, Sonex ltd. has a much more relaxed attitude about alternative engines.

In the above photo is from sun n Fun 2012, eight years later. Building a “cleanex” has a fun side also, where builders like to keep ‘traditions.’ From our 2012 SnF coverage, a picture and a comment that pre-dates the policy change by the Monnetts: “A Sonex builder next to Dan. We are having a good laugh disguising his identity because on his shoulder is a motor mount that mates the Sonex airframe to a Corvair engine, creating a “Cleanex.” Here we are kidding around about the  man in the yellow shirt entering “The Builder Identity Protection Program” because the combination is not approved by John Monnett, the airframe’s designer. In years past, John was known for having low tolerance for people modifying his excellent airframe designs. Truthfully, I know him fairly well and he really doesn’t get that upset about it as long as builders choosing other engines do not level unfair criticism at his selected engines.  There are now about 10 Cleanexes flying, and Dan is glad to work with any builder who has chosen the combination as long as they respectfully avoid Internet comments that would raise John Monnett’s blood pressure.


Many people have seen Dan and Grace flying aerobatics in “The Wicked Cleanex” on our Corvair Flyer #1 DVD. Continuous use of this type of operation led Dan to independently develop his own simple, retrofitable fifth bearing setup to reduce flight loads on the Corvair’s crankshaft. You can read about it on his website fly5thbearing.com. While people just getting into aviation occasionally view Dan’s flying as daring, I want to emphasize that it is a smooth display of skill and has nothing to do with daring or risk taking. I’ve gotten to know him pretty well, and around airplanes, Dan is pretty conservative. I would easily name him the steadiest pilot and most meticulous maintenance guy in the land of Corvairs.


Above is an early (2006) view of the Cleanex engine. Our Gold Hub and Front Starter system are clearly visible in the photo. Note that all of the engines we build have Lycoming style starter ring gears on the prop end of the engine. All of Dan’s installations use our arrangement. In the past, a handful of homebuilders and here today, gone tomorrow outfits put the ring gear on the firewall end of the Corvair. On a Sonex airframe, it is a critical that no builder operate with such a location because it puts the exposed, spinning, ring gear very close to the Sonex’s plastic fuel filler neck, which could lead to a disaster in an otherwise minor accident. To fly a ‘rear starter’ in a Sonex airframe is foolish, to promote it would be amoral.


The combination of the Sonex airframe and the Corvair proved very sucessful because Dan wisely chose a mixture of our proven parts and systems, clever craftsmanship and practical hot rodding.  Once Dan showed people what the plane was capable of, it was more frequently called “The Wicked Cleanex.”  Over time the plane served as a test bed for a number of  our parts like the Gold Prop hub and the reverse gold oil filter housing. Dan used it to prove out his popular 5th bearing system. You can read more of the story of the airplane at Dan’s Web site, www.flycleanex.com


Our approach to serving builders is different than typical businesses geared only to sell things to consumers. Our goal is to assist you on your path to becoming a more skilled aviator. The products we sell support this, but simply getting you to buy things is not what I am in aviation to accomplish.



This page is broken into the following sections:


1) Introduction

2) Engine and build options

3) installation components

4) Support for builders

5) Flying Panther and Cleanex info.

6) Builders in process

7) flight data and safety notes

8) who is WW?

9) Comments on dangerous trash.


At the end of each section there are links to supporting stories that have expanded information on concepts discussed in the section. Take your time and study it carefully.

I will be glad to answer further questions just email WilliamTCA@aol.com or call 904-529-0006. You can also check our two websites, http://flycorvair.net/ , http://flycorvair.com/ . The first is our ‘newspaper’ the second is our ‘library’ and ‘store.’ The links below are stories that already appear on these two sites, they are just arranged here to support this introduction to Corvair power for Panther and Cleanex builders. For installation components in section four, contact Dan and Rachel directly.


In the foreground above is Dan Weseman’s Wicked Cleanex. Off his wing, Chris Smith flies the Son Of Cleanex. The photo was taken over a bend in the St. Johns River in North Florida.


1) Introduction:

The Corvair has been flying since 1960, and I have been working with them as flight engines since 1989. It is a story of careful development and testing, a slow evolution to the engines we have today. It is ‘old and proven’ rather than ‘new and exciting.’  If that approach appeals to you, read on. There is a lot of material here, and it isn’t something you are going to absorb in one quick scan. Frankly, your engine selection deserves careful consideration, and it isn’t the kind of decision you should make based on a 4 page sales brochure.

Corvairs have proven themselves to serve a very broad variety of builders. Many alternative engine options are offered only as a “buy it in a box” import, more of an appliance than a machine, with little or no consideration of the builders, skills goals, needs, budget or time line. The Corvair has options to address these valid considerations, because your power plant should conform to you, not the other way around.

This said, Corvairs are not for everyone.  In the 25 years I have been in the EAA and working with builders, the Corvair has always been very popular with ‘traditional homebuilders’, the people who have come to experimental aviation to discover how much they can learn, understand and master.  The expansion of the EAA has brought more of these builders, but it has also brought a great number of people incapable of distinguishing between mastery of an aircraft or an engine and just merely being its buyer and owner.  People who’s consumer mentality and short attention spans are better suited to toy ownership than mastery of skills and tools in aviation. Corvairs, and perhaps experimental aviation, are a poor match for such people. Many salesmen in our field will gladly sell anything to anyone with green money. I am an aviator, not a salesman, and the gravity of the subject requires more frank discussion and ethics than many salesmen bring to the table.

If you came to experimental aviation to find out how much you can master, not how little, then you are among the aviators who follow Lindbergh’s timeless 1927 quote: “Science, freedom, beauty, adventure: what more could you ask of life? Aviation combined all the elements I loved.”  Even if you are brand new to aviation, I am glad to work with you. I have a long history of working with builders of all skill levels. We have a number of successful builders out flying their Zeniths who are the masters of both their airframes and engines, who had never changed the oil in a car before building their plane.  If you got into experimental aviation just to buy stuff, then any salesman will do just fine for you. If you got into experimental aviation to learn, develop your own skills and craftsmanship and make things with your own hands, then who you work with really matters. You can’t become and old school homebuilder / motor head by buying things from salesmen. They have nothing to teach you. What you will do in experimental aviation is not limited by what you already know. It is only limited by what you are willing to learn, and selecting experienced people to learn from.  If you are here to learn, I am here to teach. It is that simple.



a) – Complete Lindbergh quote is here: The Quote, 1927, C.A.L.

b) – Explanation of machines vs appliances : Machines vs Appliances Part #2

c) – Story of real engines vs ‘ideal’ ones: Unicorns vs Ponies.

d) – A direct explanation of what makes my work different: 2011 Outlook & Philosophy

e) – A moving statement of philosophy: Sterling Hayden – Philosophy



Above, a 3,000 cc Corvair, The actual engine in the Panther Prototype.  The Corvair is an inherently simple engine, It’s opposed six configuration makes it the smoothest of available power plants. It has outstanding cooling because GM put a tremendous amount of cooling fins on it and  gave it a factory CHT redline of 575F. All of our engine parts are made in the United States, as are the airframe parts from SPA.


2) Engine and build options:


If you are new to Corvairs, lets quickly cover some ground: General  Motors made 1.8 million Corvairs. brand new parts, including billet cranks, forged pistons, valves bearings,  virtually every single part inside is currently made and readily available, and will remain so. Rebuildable Corvair engines are plentiful, and much easier to find that Lycomings or Continentals. We have been working with Corvairs for 25 years, and there is no shortage of core engines or parts. If you doubt this for a second, Google “Corvair engine parts.”

The Corvair makes an outstanding aircraft engine because it is a simple, compact, direct drive, horizontally opposed six cylinder, air cooled engine. It is robust, and ‘flat rated ‘ from it’s automotive output. The engine runs equally well on automotive fuel and 100LL, and it does not care about ethanol. In its 53 year flight history, more than 500 experimental aircraft have flown on Corvair power.

The engine can be built in three displacements with three respective power outputs. They are 2,700cc / 100HP, 2,850cc / 110HP and 3,000cc / 120HP. The two smaller displacements weigh 230 pounds, the larger actually weighs 8 pounds less because it uses lighter cylinders. All engines are completely rebuilt from very high quality parts before flight. They are not just removed from cars. The parts we use are specifically selected to convert the engine for the rigors of flight use. Forged pistons, Inconel valves, chrome rings, ARP rod bolts and many other components are upgraded in the rebuild.

To absorb the propeller and flight loads a “5th bearing” is added. It is a billet housing with a very large bearing from a V-8, bolted on the end of the case. The ignition is redundant and utilizes two 40,000 volt systems, one driven by digital electronics the size of a match book, the other by a traditional set of points. The engine is direct drive, it has no complex reduction unit. It makes good thrust because it has more than twice the cubic inches of a Rotax 912. All of the systems on the engine are intentionally patterned after those on Lycomings and Continentals, because they are the  model of success in proven aircraft power plants. People who do not acknowledge certified engines as excellent models of success are often just zealots.  To succeed in experimental aviation you need dispassionate information not emotional opinion.

One of the unique features of the Corvair is that it can be built at home, from our information and parts and a locally acquired rebuildable engine, or it can be purchased from us, test run with logs. 90% of current builders are building their own engine at home. Only 10% of the builders opt to have us build their engine. We have happy to serve both builders. In either case, Corvairs are the best match for builders who want to understand and be the master of their engine.

Because of the plans built vs production engine nature of the Corvair, there are large variations in how much builders budgets run. Below is a quick look at the differences. Keep in mind, these budgets are for first class, completely overhauled, zero timed engines with 5th bearings, starting, ignition and charging systems. We have clever builders who have built and flown engines for less than $3,000, but this not representative of main line builders. The numbers below are much better for Zenith builders to budget on.


2,700cc / 100HP typical homebuilders budget: $6,500- Same engine assembled and run from us $9,750

2,850cc / 110HP typical homebuilders budget: $7,500- Same engine assembled and run from us $10,750

3,000cc / 120HP typical homebuilders budget: $8,500- Same engine assembled and run from us $11,750


If you are attracted to the concept of building your own engine, but have not built motors before, Good.  About half of our builders have never built any kind of an engine before. Our main work is teaching people what we know and providing the parts to work with. Our system does not require anyone to be a machinist nor to have previous engine experience.

The procedure of building an engine in your shop follows this format:

1) Get a conversion manual and DVD’s from us, use them to find a rebuild able core engine locally. Disassemble this engine following the steps in the DVD.

2) Send the crank and heads to our approved facilities for rebuilding and modification. They come back ready to ‘bolt on.’ Other parts of the engine are cleaned and inspected. The parts to convert the engine are ordered from us, many of the standard rebuild parts like lifters and gaskets are available from local auto parts stores. We do not ‘middle man’ anything you can directly buy.

3) Assemble these parts according to the manual and DVDs. There is no machine work required, only basic tools are needed, and a few specialty tools like a torque wrench. Many builders attend our free Corvair Colleges and directly learn hands on skills. You can even bring your parts and assemble them under our supervision, and test run your engine on our equipment. College attendance is a plus, but not required. Our methods work without direct training; a good number of engines are built and flown each year by builders who have never met me in person.

4) The test run serves several purposes. We teach people to build one of  three specific models, and we teach them to use specific parts. Not only are these proven, but it also allows me to verify from a remote location that the engine was assembled correctly. A builder can report his static rpm, CHT, oil temp during the test run with his Warp Drive prop at the specified setting, and I can confirm the output and assembly of the engine without seeing it personally.

If you would like a sample of the information on working your way through the above four steps, get a look at this: Getting Started in 2013, part #1, Crankshaft process options.

We also have all of the ‘getting started’ series on a single page, at this link: Getting Started Reference page.

I have broken down building a Corvair and installing it on your airframe into 42 “groups”. Part #1 is about  ’Group 1000′ the crankshaft. If you would like to look at every part that goes into a Corvair, along with the conversion parts we sell, look at Groups 1000 -3300 at this link to our catalog: http://www.flycorvair.com/products.html

If you would like to read above the value of proven engines, read: Why Not the Panther engine?

All builders get started with a conversion manual. The first part of the above link is about manuals and DVD’s.  The direct link to the manual is: http://www.flycorvair.com/manual.html. almost all builders looking for a rebuild able engine also order the Disassembly  DVD, which covers core engine selection visually. The direct link to it is: http://www.flycorvair.com/videov.html We encourage everyone to get started with information, even if you are pretty sure you would like to purchase a production engine from us. If you eventually buy an engine from us, we directly reduce the price to rebate all the money you spent on manuals and DVD’s.



a) – Corvair Weight story: Corvair vs O-200…. weight comparison

b) –  Samples of our production engines:  2012 Corvair Engines For Sale: 100, 110 and 120 HP

c) – For an explanation of ‘flat rating’ and an engine build : Shop perspective: Mastery or ?

d) – A story about engines running on our hangar Dyno: http://www.flycorvair.com/thrust.html

e) Engine of “Cleanex” builder: World’s Strongest 3,000cc Corvair, built by Greg Crouchley

f) A story about the evolution on 120HP Corvairs: 3,000 vs 3,100 cc Corvair engines.




Above, a 2009 photo from our workshop. I kneel in the workshop next to motor mount Number 100 for the 601 XL.  Most experimental aircraft companies, both large and small, fail because for two simple reasons; First, the ownership cannot physically make the product the sell, and second, their financial backers are unwilling to go several years before seeing the payoff.  Neither of these conditions are true about our business nor SPA/Panther. We are craftsman and homebuilders first, and neither of us has partners nor investors. Few people new to experimental aviation understand that this is key to company stability and longevity, not big size nor flashy promotion.


3) Installation Components for the Panther & “Cleanex”:


Normally we provide every part it takes to install a Corvair in your airframe.  The Panther and the Cleanex are different because Dan developed these specific installations himself.   It is important to understand that these installations work seamlessly with our engine components, and they are custom adaptations of systems that have long been proven to work very well.  In the case of the Sonex airframe, there have been a handful of other people who tried, with poor results, to put a Corvair on that airframe. If you have heard a poor report on a Corvair powered Sonex, it is important to understand not all Corvairs in these airframes are people following Dan’s proven path.

Here’s a 2004 view of the underside of the Cleanex’s motor mount. Dan designed this mount combining the basic geometry of the Sonex airframe’s landing gear attach points and our traditional Corvair bed mount. The structure is well thought out and perfectly triangulated. Although it looks heavy, it is not. It weighs 13.8 pounds, only four pounds heavier than the factory Jabbiru 3,300 mount. Dan’s mount has flown hundreds of aerobatic maneuvers. Dan’s motor mount page is here: http://flywithspa.com/flycleanexcom/cleanexenginemount.html


  Being air cooled and carbureted, The Corvair is one of the easiest engines to install. Many companies that are good at selling things are poor at teaching things, like how to install their products. Teaching is the very cornerstone of my work, I am a skilled writer, we run Corvair Colleges, and we have a simple engine. All this adds up to a comparatively easy engine to install. There is no need to rush it, but I can do it working in one long day.

 Installation part numbers are Groups 3400 through 4300 in the second half of our numbering system. Get a look at this link: http://www.flycorvair.com/products.html It contains installation component lists for other Corvair powered airframes, but the list is very similar to the required items for Dan’s installations. The detail items on electrical and fuel systems are identical, and you can review the SPA website for the specific details on the Panther and Cleanex installation components. There are many good photos here: http://flywithspa.com/flycleanexcom/cleanexphotos.html

For the Cleanex, Dan and Rachel offer their own Nose bowls, Cowls, Mounts, baffle kits, Exhausts and intake manifolds. While you are there, get a look at his 5th bearings, rear alternators and Billet Cranks. A sample of their parts page is here: http://flywithspa.com/flycleanexcom/cleanexnosebowl.html

Dan and Rachel are just in the process of organizing the Panther/Corvair components like the mount, cowl, intake, exhaust and baffling.  You can check the Panther website for up to date information on these parts. If you would like to see the Panther engine runninga prop test, click on this link: Panther
Engine propeller test

Although the Panther is new, the systems are fully tested and well proven. It is important for builders to understand the engine test program went flawlessly because it used custom variations on proven systems. For example, the Panthers exhaust is made from the same materials and processes and uses similar design to the stainless systems we have made for other airframes for more than 10 years. The carburation, intake, cooling and spinner are also variations on long proven themes.

Many people new to building initially think that very economical engines like the Corvair must also be inexpensive to install. In reality, the cost of items like motor mounts and cowls are not affected by the cost of the engine they mount and house.  A mount for a $30K UL-350 and a $7K Corvair have about the same amount to tubing and welding time in them, and thus cost about the same. Most engines have installation kits with exhaust, cowl prop spinner etc, run from $3,000 to $6,000. The Corvair is near the bottom of this range, but the savings of using the Corvair is mostly in the engine, not the cost of installing it.

Above, Chris Smiths plan’e uncowled with Dan’s in the background. A ground run cooling shroud sits atop Chris’s engine. Dan stand on the edge of this 2007 photo I took in his hangar.


a) – For an example of 74 years of aircraft welding talent: Zenith 601/650 Motor mounts, P/N 4201(A) Both Vern and I are friends with Dan and assisted him with some of the welded parts that went into the Panther prototype. Dan is a skilled craftsman and a welder on par with us.

b) – To learn about the Stainless exhausts we make: Stainless Steel Exhaust Systems . These are identical in material and construction to the Panther and Cleanex stainless systems.

c) – Louis Kantor’s 601XL running for the first time in our front yard: http://www.youtube.com/watch?v=626uwVbc0gM The plane is one of more than a hundred  Corvair powered planes that utilize Dan’s 5th bearing. Dan used his Cleanex as the chase plane on this planes first flight.



Above, 2004 at Oshkosh: Next to our personal Corvair powered Zenith N-1777W, I explain our dual ignition arrangement two executives from Falcon insurance, The EAA’s provider. To offer real support, an alternative engine provider must be an effective advocate for his builders on many fronts, including meeting the requirements of underwriters. Just being an engine guru is not nearly enough. Corvair engines that follow our design,  including to ones assembled by builders, are fully insurable at the lowest rates, right from the first flight, because they have an outstanding safety record. Having good effective hands on support is a critical element in this outstanding record.


4) Support for Builders:


Builders selecting a Corvair for their Panther or Cleanex project have an advantage that is hard to overstate; Because Dan and I have been friends for more than 10 years, I am very familiar with both of his installations. I followed his Panther development from the first sketch through the flight test program. While the design can and will be flown on a broad variety of engines, it will be a long time before any other alternative engine provider understands the design and program as well I do.

Many new builders mistakenly believe that they can marry any engine they like to their chosen airframe. In reality, compatibility goes far beyond horsepower ratings and weights. To be successful, it is critical that the engine match the designers perspectives on reliability, risk management and ethics. Differences on these subjects create issues builders can rarely resolve themselves; conversely, having both support teams share the same perspective gives builders strong allies. In 25 years of working with homebuilts I have met many designers and innovators I respect, but my personal perspectives share more common ground with Dan’s than any other person I know in this industry. Please take a moment to read: Panther Roll out.


Beyond the basic engine and installation components, we offer many forms of support to Corvair builders. :


a) We have a flight operations manual with specific test flight plans and procedures: http://www.flycorvair.com/ops09.html Dan wrote one of the chapters in this manual to share his experience with Corvair builders.


 b) We hold 4 free hands on technical seminars called “Corvair Colleges” every year.  For an introduction to Colleges, read this link: http://www.flycorvair.com/cc21.html  An overview of upcoming colleges is at this link:  Upcoming events, Airshows and Colleges #26-28. If you would like to see video of a College, here is a link to Corvair College #17 http://www.youtube.com/watch?v=wfa85e3ibI4&playnext=1&list=PL1D40A102EC2A194D&feature=results_video Dan and Rachel attend many of the colleges and were our Co-hosts at Corvair College #23.


c) Woody Harris, subject of this story:  Zenith 601XL-2,850cc, Woody Harris Is our West Coast representative. Although we have held 5 Corvair Colleges in California,  we only make one trip to the west per year. Woody covers all the shows and events from Arlington to Copper State when we can’t be there.


e) I am the last guy in aviation who still makes free house calls. Over the years I have made more than 400 in person visits builders projects. I travel extensively, and go out of my way to include builders workshops on these trips.  These stops and the colleges allow me to really understand the needs, strengths and dreams of rank and file builders that no one can read in email or at an airshow. for a sample, read this story: Corvair House Call, Range: 335 miles.


f)  By my continued advocacy and industry relations, Corvairs have full insurance, at the lowest rates, available from a number of sources. If you would like to find out more Contact Bob Mackey, VP of Falcon insurance, The EAA’s designated provider, seen on the left in the photo above.


g) Over the years, we have built a very tight knit community of like minded builders. If you read this story about fools at our county airport: A visit to the insane asylum, and it sounds like your airport, and if your local EAA chapter is devoid of homebuilders and filled with negative people, you will find the Corvair movement to be a powerful antidote. Many Corvair builders catch several colleges a year, there they find positive, outgoing, energetic builders, effectively making the Colleges their “local EAA chapter” We have worked very hard to attract outstanding people interested in accomplishing their goals. I  go out of my way to encourage new builders but I am intolerant of people who are compulsively negative. I am willing to be a cheerleader, but not a therapist.



Above, Chris Smith’s Cleanex after painting. Chris was building a Sonex airframe from a kit and met Dan as Dan’s airplane neared completion. Chris opted to build a close copy of Dan’s aircraft. Although Chris had many years of flying experience, he had never built an aircraft before. Because of this, he wisely chose to follow Dan’s proven format closely. When Chris’ aircraft was done, it earned the nickname “Son of Cleanex.” It first flew at the end of 2006, and it served Chris through several hundred hours flying over the southeastern United States. Today the aircraft is owned by Ron Monson, who has put a great number of flying videos of it on You-tube.


5) Examples of flying Corvair powered Sonexes:



Above, The Cleanex of Dale Williams taxis out at Corvair Colle #27. Read more on the man and the plane here: New 3,000 cc Cleanex, Dale Williams, SC

Above, Cleanex by Chuck Custer, after flying to Corvair College #25. This aircraft is one of approximately 12 that have flown utilizing Dan’s installation.



Above, Clarence Dunkerley beside his 2850 cc Weseman bearing equipped powerplant destined for his Cleanex project. Sharp eyes will  notice that this is equipped with the Reverse Gold Oil Filter Housing which we developed specifically  for Corvairs going into Sonex airframes. Photo taken at Corvair College#21.


6) Examples of Builders working on this Combination:


Many experimental aircraft companies like to tout how many of their product has sold as a measure of  success. Sales numbers on only a measure of their success, not that of builders. The only number that counts are how many builders that make it all the way to flying and enjoying their creation. It is a fact of marketing that it is far easier to keep finding new buyers to spend money than it is to support the ones that already spent the money, all the way through flight.  This is why many aircraft companies have planned lifespans of only 48 months, so they make all the sales and fold up the tent before they have to do the real work of supporting builders.

We are very different.  I have been working with Corvair builders since 1989. I am in this for the long haul, and my measure of success is getting people flying. Likewise, Dan has been working with Corvairs since 2003, and has been offering parts like his 5th bearing design since 2006.  If you select a Corvair engine, we will be your allies in completing your plane, just as I have been for many others before you.

If your goal is to merely buy something, you need only find a salesman with an engine to sell. If your goal is to learn about, understand, build and fly your plane, you need an instructor-guide-mentor, an aviator not a salesman. Think it over: If your goal was to climb mount Everest, there would be plenty of people you could buy equipment from, but that isn’t the same thing as finding a Sherpa who has been to the top to act as your instructor and guide.  A big part of why experimental aircraft have a 20% completion rate is that most people purchasing a kit or an engine have not spent 3 minutes learning how to differentiate between a salesman and a guide.

Below are a sample of our builders, each of whom I am going to see all the way through their aircraft finished and flying:

Above, Cliff Rose, Cleanex builder from Florida, with his 2700 cc, Weseman bearing, Falcon head engine with Reverse Gold Oil System. Cliff  spared no expense to acquire all the parts of his engine. Still, he spent less than one third the cost of an imported engine. More importantly, he has the well earned  pride of creating his own engine. Photo taken at Corvair College #19.

Above, Aerospace engineer Paul Salter stands beside the Panther prototype. Paul is close friends with Dan and Rachel and has played a significant supporting role in the Panther introduction. He is building Panther beta airframe #2 for himself, and he is already collected most of the parts to assemble his own 3,000cc /120hp Corvair, which will be a direct clone of the Corvair in Dan’s prototype.

Above, Phil Maxson (Left) gets his airworthiness certificate for his 2700cc Corvair powered 601XL from legendary DAR Johnny Murphy, in our old Edgewater hangar in 2006. Today, Phil still flies and enjoys it, but is also well at work on Panther Production kit #1, which will be powered by a 3,000cc Corvair. We awarded Phil The Cherry Grove Trophy for 2013, as Corvair aviator of the year.


Above, Waiex builder Greg Crouchley stands beside me after the test run of his Corvair at our hangar in 2012. Although headed into a Waiex, Greg’s engine is essentially a clone of the Panther’s, including a Weseman billet crank. Read about the man and the engine at this link:World’s Strongest 3,000cc Corvair, built by Greg Crouchley 

If you would like to read a story about and see the film on a running 3,000cc Corvair for a Sonex built at a College, Click on this link: Corvair College #27 run on film. It is the engine of Amit Ganjoo, who is also the builder with the yellow bag over his head in the photo at the beginning of this story.




7) Operational Data for this combination:

Dan and Rachel’s website will be the primary source of performance data for Panther and Cleanex builders. Our website have a continuous flow of discussion on Corvair operations for all types of airframes. If you would like to read a story about detailed flight data collection on a 2,850cc 750, check out this link: CHT part #5, flight data from Zenith 750 . It is an example of the type of information exchanged between our builders.  If you are drawn to aviator’s groups made of intelligent thinking people, you will fit right in with Corvair builders.

Here is a visual example of testing: Panther Engine propeller test

And you can also read a story on operations here: Starting
procedures on Corvairs, 2,000 words of experience.
 Our .net website has more than 375 different stories on it, about 225 of them are purely technical posts with expanded operational information and experience.

I have long stated that I can teach a 12 year old how to assemble an engine, but what we are really trying to share with people is a knowledge base that will effectively allow them to master the engine and use it with good judgment, something a 12 year old (and some adults)  cannot do. If some of the articles that I write don’t initially sound like a set of instructions, consider for a moment that the message of the artice may be about the critical element of Judgment.

If you would like a single example to effectively demonstrate that I am an aviator not a salesman, it is the type of data that I discuss with builders. No salesmen will acknowledge accidents nor difficulties that involved their products, even circumstantially.

Conversely, I am here to teach people what they need to know. I have a long history of writing about subjects that salesmen wouldn’t touch with a 10 foot pole. I write about accidents and friends I have lost, honest mistakes people made and things you can learn from them.  Just about everything know in aviation cost someone dearly to learn. If you are unwilling to talk about these things in plain language, people are doomed to repeat them.


Risk Management, Judgement Error, money in the wrong place. is the story of our only fatal accident in a Corvair powered Zenith. (There is another below, but it was a different company) The NTSB pointed to an incorrectly assembled carb, but read the story and decide if judgment isn’t the root cause.

“If only someone had told him……” is a story about people who don’t listen. Guy A and Guy B were both Zenith 601 builders. Guy B was the passenger in the First 650 accident (AMD airframe- O-200 engine, ruled pilot error). Guy A was a well known and liked Zenith builder and flyer, who quit aviation after this incident.

Risk Management, Factor #1, Judgement. Covers how developing and exercising judgment is paramount to managing your own personal risk.

Risk Management, Experience vs Judgement. Ken Terry was a friend of mine and a huge influence on Grace’s flying, and her development as a pilot. The story is about how experience, even 40,000 hours of it is not a defense compared to exercising good judgment.


Dan Weseman and Dave Dollarhide having a good time at Sun n Fun 2013. They both are in the last story “Friday night” in the link “Three aviation stories”.


 Three Aviation Stories  covers my personal perspective on risk, and what level is worth managing, and how aviators come do deal with this. It speaks of meeting Al Haynes at two points in my life, 14 years and a world of experience apart. It also covers how several members of our EAA chapter each looked at loosing two friends.



Above, A photo taken at Sun n Fun 2006. My wife Grace Ellen and myself, in front of the first Corvair powered Zenith, our own N-1777W. The plane was the first XL model with conventional gear.  Grace is a skilled pilot in her own right. She has been a pilot longer than I have, holds more advanced ratings and owns two aircraft. As a point of ethics, we do not promote, advocate nor sell things we have not personally flown behind.


8) Who is William Wynne?

Modern consumer sales logic dictates that that business should ‘de-personalize’ themselves so consumers find nothing objectionable about the provider while they are spending money.  That model may work elsewhere, and even have advocates experimental aviation, but I don’t buy it.  I contend that Aviation is a different arena, and who you are dealing with, and their ethics, experience and perspective matters.

Building a plane or an engine is a marriage of sorts between the builder and his airframe or engine company. I believe that it is best if everyone goes into it well informed with their eyes wide open. I am always surprised how few people even Google the name of a person they are thinking of working with. You don’t need to see eye to eye with them on every point nor even love them, but the relationship must absolutely have trust and respect operating in both directions. In 25 years I have seen many builders try to justify buying a product from a provider they didn’t really trust. It never works out. It doesn’t matter how good it looks, what it costs or how great it is supposed to work, if it is from a bad guy, it isn’t worth buying.

I could write a quick paragraph about how I am a pilot, a 22 year A&P mechanic, and that I hold both an AS degree in Maintenance and a BS in Professional Aeronautics (accident investigation) From the worlds #1 aeronautical university, Embry-Riddle , but I don’t think that any of that explains my commitment to builders nearly as well as the flying planes of our builders and things we have accomplished. Henry Ford said “A man can not base his reputation on what he says he will do; only what he has done.”

I am plain spoken. to understand why, read the ‘Effective Risk Management’ story below. I have many friends who are experienced aviators who value plain talk. This type of speech also tends to offend people who dabble in aviation and would rather read polite things that align with their pet opinions. I am in aviation to share experience builders need to know, not say things people want to hear. Below are a selection of stories, some humorous, but all with a point, that give people a better understanding of who I am. From there you can decide if you choose to work with me as your engine mentor.


a) Fixing America is going to cost each of us $1.69

b) Greatest Book on Flying Ever Written, (Is your life worth $16?)

c) In defense of plain speaking……

d) Turtles and Cell Phones, 6/24/13.

e) A thought on Easter….

f) Happy Father’s Day William E. Wynne Sr.

g) Effective Risk Management – 2,903 words




9) Notes on trash:

Not all things called a Corvair represent my work or designs. Over the years, our success and willingness to share information has brought out a number of short lived companies that were run by rip off artists, and mentally ill people. Particularly, there have been four businesses that made poor copies of our parts or untested garbage. All of these are bankrupt today. Today, I have just heard that another is coming back with a new name. The story will never end as long as people don’t do their home work or believe that they are getting a bargain. You can read about one of these companies at this link: Cloudn’t have happened to a nicer guy……

I warn people all the time not to buy things from these people, or to buy this stuff at the flymart. For examples of things no one should have bought, look at this story: Built by William Wynne? Built according to The Manual?

Let me be absolutely clear, that I will be polite to people, but I will not work on, offer advice on, or help with products made by bankrupt people that I considered vermin.  Nor will I allow these people to attend any of the Colleges. This isn’t out of spite, it is to protect these builders lives. They all want to put a band aid on their bad purchase and make it “good enough to fly.” A band aid isn’t going to do it, an amputation is in order. People who blew $12K on junk don’t want to hear this, they are still looking for a cheap out that doesn’t exist.  I will not assist them in the delusion that they have found one.

On line discussion groups and websites have a small number of old posts from people who bought trash like this for their projects. If you look closely, these people offered great testimonials, but later abandoned their builds. Look at the dates on many of these posts and then compare them to FAA aircraft registrations on Landings.com.  From looking at our sites you can see photos of dozens and dozens real builders with real names and flying planes. I encourage builders to do their home work; our track record will speak for itself. -ww.


Corvair College #27 run on film


“Cleanex” (Corvair-Sonex) builder Amit Ganjoo sent us a you tube link of his 3,000cc/ Dan bearing engine running on our stand at CC#27:


Amit started his assembly at CC#24, also in Barnwell, one year before. He went home and finished the assembly, and later returned to CC#25 in Florida to observe/socialize (popular with completed engine guys and flyers). For CC#27, Amit decided that he would rather do his break in run on the stand than his airframe. His aircraft is complete except some small wiring, but it was a simple matter to pull the engine in an hour and pack it up for the 400 mile ride to CC#27.

The engine ran beautifully. The film shows the actual first start. Even after a few decades of doing this and several hundred engines, I still like watching a number of cold metal parts in close formation that have never run together start and run smoothly in 2 seconds of cranking.

Note that the engine is not primed other than the accelerator pump in the carb, and it is starting on the points side of the distributor. So much for the arm chair engineers still speculating that long intake tracts somehow don’t work.  They will still be speaking about that when Amit is out flying the plane and engine he made with his own hands.

Amit is many things, from skilled IT guy through devoted family man, but a year ago “Motorhead” was not on his résumé.  Often, when you learn a lot of information, but it comes in sequential bite sized chunks, as building a Corvair does, you loose perspective of how much you have learned. Often builders are given a new overview of their learning and achievement at the moment of first run. A moment well spent in the company of other ‘traditional homebuilders’ at a Corvair College. -ww


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