Understanding Flying Corvairs Pt. #8, Learning from other’s mistakes.




If you have not seen the Intro to this series, you can read it here: Understanding Flying Corvairs Pt. #1, Intro., It will explain the goals of the articles. Please take a moment to read it, including the comments section.




In recent weeks I have written several stories about a builder who was trying to fly a Corvair powered Zenith 601XL on one of two SU carbs from a 60 hp British car. For the people who assumed that I was just making the whole thing up to illustrate a point, let me share this link to the man’s webpage:



I wrote the story How I became a genius in 6 minutes about the man’s first flight, where the engine was severely damaged. Yesterday I commented on his choice to still try to use the same carb in: Thought for the Day: J.S. Mill – On Liberty. Today several people sent me a link to his page where he reports his carb still chronically leaning out.


If you care to read the man’s description, you can see he suspects that his joyous British carb can’t take forward air pressure. If he had cared to read the stories I have written on Corvair Carb choices, he would have come across this personal story about Bing carbs, which work on a nearly identical principle as the SU:


“A personal example of why I don’t like Bing carbs; Steve Rahm, our neighbor at Spruce Creek, designed and built the ‘Vision’. It had a Stratus EA-81  Subaru with two Bings on it. Since they basically ran full time carb heat,  he wanted to try cool ram air in search of more power. He went as far as testing the set up with a gas leaf blower on the ground. He did this because some people said Bings don’t like ram air. On take off it worked great, until the plane hit 70mph over the trees at Spruce Creek. Then the carbs  shut off all by themselves.


Plane slowed to 65, power comes back a little. Very  skilled flight at tree top level is executed. Several minutes of listening to  the rough engine clawing its way around the pattern.

He appears on final gliding  in. Steve was a new dad, and his own father had been killed in a plane when  Steve was a young man. I could not believe that I was about to witness a  horrific repeat of a family tragedy. He barely made it, touching down at 75  mph. People on hand thank God aloud.


As the plane rolls out in the three point  attitude, the airspeed drops below 60, engine comes back to full power and tries  to take off on its own. Steve later tells me he almost had a heart attack at that  moment. He switches to a Lycoming with an MA3-SPA. which operates on the stone  age concept of the throttle opening and
closing when the pilot wants. (the throttle on a Bing is controlled by a vacuum diaphragm) Steve is a  master skydive instructor with
4,000 jumps, he can keep his cool under pressure.  I figure most other pilots in a plane with a five mile per hour  wide speed envelope and 100′ altitude would have bought the farm. -ww

From the story :A question of Carb location…..



I have no idea why someone wishing to do something different with carbs would not read all the available information. The mans website notes says that if his tests don’t work, he may later use an aircraft carb like I recommend.


 I sit here and type this less than 15 miles from the spot in Florida where Ronnie Van Zant of Lynyrd Skynyrd is buried. On the subject of people who like to experiment with substances known to be harmful, he sang the song “That Smell”, which included the bit of wisdom  “Say you’ll be alright come tomorrow, but tomorrow might not be here for you.”*





Above, three aircraft parked in our front yard. L to R, Louis Cantor’s 601XL – MA3-spa, Grace’s Taylorcraft –  NAS-3 and Dan Weseman’s Cleanex, MA3-SPA. This was taken on the day we flew a flawless test flight in Louis’s 601, the same plane as the man in question is trying to fly on the British car carb. I ask, why not have the sucess that Louis had?




 Most of the people who are looking at a cheap carb don’t think I know what I am talking about. I find the concept that a guy who has tested either zero or one carb on Corvair flight engines assuming that his guess is more valid that my 20 years of testing, annoying. On the subject of low-cost, it isn’t a stretch to say that I know more people building a Corvair engine for a  plane than any other person on Earth. While cost may be an initial attraction, the reason why people stick with it is to learn something, be proud of what they  have done, and experience this in the company of other like-minded aviators. If you want to fly cheap, rent  a Cessna 150. If you want to do something rewarding, fly something you built  with your own hands that is reliable and works well.


While I advocate the use of aircraft carbs, I have also tested Dyno many things from 1 barrels to tuned port EFI. If someone wants to use a cheap carb, there are many better options than a British car carb. Above, a 1 barrel down draft ford carb. If you would like to read more on our testing of this,  In Search Of … The Economical Carburetor



From Wikipedia:

* On Labor Day weekend in 1976, Gary Rossington and fellow Skynyrd guitarist Allen Collins were both involved in separate auto accidents in their hometown of Jacksonville. Rossington had just bought a new Ford Torino, and hit an oak tree while under the influence of drugs and alcohol.  Van Zant and Collins wrote the song “That Smell” based on the wreck, and Rossington’s state of influence from drugs and alcohol at the time. It starts with the lines:”Whiskey bottles and brand new cars, oak tree you’re in my way.”



You can see a live 1977 performance of the song at this you tube link: https://www.youtube.com/watch?v=hib4n9RmFrQ

Playing in it are Ronnie Van Zant, Allen Collins, Billy Powell, Steve Gaines, Leon Wilkeson, Artimus Pyle and Garry Rossington. Ironically, today only Pyle and Rossington are left alive. The others died at ages 29, 37, 56, 28 and 49 respectively.


About William Wynne
I have been continuously building, testing and flying Corvair engines since 1989. Information, parts and components that we developed and tested are now flying on several hundred Corvair powered aircraft. I earned a Bachelor of Science in Professional Aeronautics and an A&P license from Embry-Riddle Aeronautical University, and have a proven 30 year track record of effectively teaching homebuilders how to create and fly their own Corvair powered planes. Much of this is chronicled at www.FlyCorvair.com and in more than 50 magazine articles.

3 Responses to Understanding Flying Corvairs Pt. #8, Learning from other’s mistakes.

  1. Spencer Rice says:


    I have really enjoyed these Understanding Flying Corvairs series! Keep it up! Interesting that you posted the form post of who you have been talking about. I have actually had lengthy conversations with him over the zenith.aero chat.


  2. dan-o says:

    that ole ford downdraft brings back memories of my first car, a 65 ford falcon, 170 c.i. it wouldn’t hit 60 mph going downhill with a tail wind. which is probably why I am still alive today, had a few buddy’s who’s dads let buy hot cars and killed themselves before they learned to drive. I am going with the Stromberg as recommended in the first conversion manual. dan-o

    • Thomas Clepper says:

      Hey, dan-o, Your comment above reminds me of my similar experience with my first car, a 1966 Ford Falcon, 170 CID, 3-speed automatic. Top speed on my Falcon was 96 MPH–that too, downhill with a good tail wind! I can point you to the exact patch of asphalt in Rockdale County Georgia where I achieved that milestone. That car was all over the road, shaking, shimmying, and rattling. And I found only one spot in town, (Conyers) where I could get the thing to bark a tire–pulling onto the blacktop from my girlfriend’s house. Memories circa 1976. Best to ya!, Thomas

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