Corvair - General Info

[kmacht]

Not sure on the sonex but there are a number of corvair powered zenith aircraft with more than 500 hours on them and long cross countries. I suspect that the corvair sonex stories are not well published because of the sonex factory stance of making them taboo and asking that they don't call their airplanes a sonex.

Try this site for some examples.
https://flycorvair.net

Keith
#554

[pfhoeycfi]

...odd website, hard to tell what the product or service is.

[lutorm]

...odd website, hard to tell what the product or service is.

I don't think it's meant to be a commercial website.

http://flycorvair.com supposedly has the business offerings, but it doesn't seem to be working.

[GordonTurner]

I think WW has partnered with Dan Weseman and the commercial side of the operation is on the Panther website https://flywithspa.com/

Going into Corvair engines is a little different than other motors. Start by reading. Proceed by buying the conversion manual....and reading. If you are intimidated by trying to find a raw engine they will sell you that part. They also offer a limited amount of built to order motors.

Gordon

[waiexpilot3mj]

There are quite a few Corvair powered aircraft with high hours and long cross country flights. Most of those aircraft however are not Sonex. Individual make and model websites will help your research.

An example would Mark Langford’s KR2 with a 3100cc Big Boy Corvair. Mark has accumulated over 1130 hours on his plane and has one of the most informative builder websites in the nation when it comes to the Corvair Flight Engine.

Take a look at his website at; http://www.n56ml.com/ and https://flywithspa.com/product/corvair-flight-engines/ . The Corvair has an excellent operational flying history do the research and listen to the pilots who are flying, built or flown with the engine. T often people will repeat from others who have no actual flight experience behind the engine but “new a guy who knew a gut that” if you know what I mean. The same can be said about the AeroVee and Lycoming. I have had over 50 years as pilot and have flown my share of aircraft. Some I did not like one bit and some bring nothing but fond memories.

We here at the Florida Sonex Association currently have 7 members who are using the Corvair Engine ranging from the 2850 to the new 3.3 Ltr either built by owners or purchased assembled from Sport Performance Aviation or William Wynn of Fly Corvair. I have not head any complaints from any of them to date.Keep in mind that our membership is not confined to Florida; we have members all across the USA.

I am one that built his own from SPA and WW components. I had almost 600 hours on my AeroVee but wanted to increase my climb and cruise performance and had known Dan and William for many years. After talking with them and being very familiar with Dan’s Cleanex and doing additional research I decided on the 3.0 Corvair with the BTA fifth bearing.

I now have well over 20 hours on my 3.0 and couldn’t be happier with the performance and temps.
I am still breaking in the engine and enjoying the new performance while flying when able and the weather allows. The FSA really keeps me busy these days. I will publish all my testing results great, just good or other later this spring for the FSA News Letter. Right now everything has been great and beyond my expectations. I will email copies to all of those who ask after completion and verification of the numbers.

If anyone has a question or needs additional information about the conversion process with the Sonex or Waiex feel free to contact me at my email offline or at the FSA at mike@floridasonex.com or visit our website at http://www.floridasonex.com

[lutorm]

I don't understand what the source of conflict with Sonex LLC would be. They sell an airplane kit, without an engine, and whatever engine I put on that kit, the airframe is still a Sonex. It rubs me the wrong way that they don't want those airplanes called Sonex. If you modified their kit, I could understand that they don't want to be implicated (and I certainly understand that they don't want to support other engines than those they sell) but the engine is completely separate from the airframe and has a separate entry in the FAA registration.

I would have thought that having developed aircraft conversion engines themselves for several decades they would support others working to provide reasonably priced powerplant alternatives for experimentals.

[SonexN76ET]

I would suspect Sonex’s issue was due only to the Corvair’s weight being beyond the weight limit specified by Sonex. For what it worth, Van’s Aircraft has also warned their builders about using engines that exceed their weight specifications (I.e. people putting IO-540s in RV8s). The weight argument is not just focused on the Corvair but also the O-200. Jeremy Monnett did a webinar on weight and balance which should still be available online at the EAA website where he addresses these issues.

Jake

[daleandee]

I trust that there will be no objection if I copy a couple of posts about the Corvair that are hidden under the Continental O-200 thread. Here you will find some good information and insight into the make-up of the Corvair engine. I agree wholeheartedly with his point about William Wynne. William himself has made it clear that, "you don't have to like someone to learn something from them."

As an aside to the engine failures that are discussed in the second post below ... many know that like the earlier VW conversions, Corvairs went through a period where cranks were being broken. That is history as there are brand new stock and stroker billet cranks available as well as Nitraded and properly machined & reworked 8409 GM cranks. William now requires a 5th bearing to be installed on engines built to his specifications. Some Peitenpol builders have not used the 5th bearing and while they had no issues for many years, now it is highly advised that all Corvair conversions install a 5th bearing. Besides it's just good sense!

I fully understand the frustration he speaks of about the many Corvair experts that have never seen, worked on, converted, watched fly, or flown behind a Corvair engine converted correctly for aircraft use. To any that have a genuine interest in the Corvair engine for aircraft use I would again urge you to go to some of the links provided in this thread and begin to do a bit of serious research. As noted before, this isn't the engine for everyone and other great choices are available. This is the one I choose to use. If I can help you, I will.

Hope this helps,

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
166.7 hours / Status - Flying
Member # 109 - Florida Sonex Association


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Re: Continental 0-200
Post by Jgibson » Mon Aug 14, 2017 6:55 pm

I'm sold on the Willliam Wynn Corvair and would build with nothing else. It can be built cheaper, or go full tilt with a new forged crank and 92mm barrels and come in lighter than the O-200.
It was designed to make up to 180 hp at 5500 rpm, and is loafing in the aircraft version. William is eccentric, however he tests his products intensely. No need to engineer a motor mount because his business partner Dan sells them ready to go. The new 5th bearing setup is well engineered and well made.
Standard Marvel Shebler carb, redundant ignition, no junk Chinese parts. I've actually TRIED to blow a turbo model in a car up without success.
Zenith has embraced their engine and supplies EVERYTHING necessary for a full install down to cowling, exhaust, etc.
Dan built the first 'Cleanex' and now offers nose bowls, exhaust, mounts, and almost everything necessary to do the install on the Sonex. But still Sonex stonewalls their product.
Remember that there are almost NO old parts in the Corvair airplane engine. Cases, oil pump accessory case, and if you choose to build frugally, the forged crank that GM spent 100's of millions to develop.
A 100 hp model just sold on Barnstormers WITH a new Dan Wessman crank and rods, exhaust, carb, intake, baffling for under $6,000. Models can be built up to 125 hp with Dan's new 'stroker' crank.
And remember: an engine that was DESIGNED to run at up to 5,500 rpm.
I just don't get Sonex' resistance unless it's purely personal with William. I'm not buying someone with a 'normal' personality. I'm buying a bullet-proof engine that I trust my and my loved ones life.
I have NO CONNECTION to either William or Dan. But I've been a fairly decent aircraft mechanic and restorer for the past 40 years and have a lot of experience with a lot of different power plants. The LAST one I'd consider a potential candidate for aircraft use would be the VW.
JMHO
Jgibson

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Re: Continental 0-200
Post by Jgibson » Tue Aug 15, 2017 8:51 am

I challenge Kai to find me NTSB reports of Corvair quitting because of the basic engine core itself.
Any that I researched quit because of failure of support systems (carb). And your issue with balancers is....? Do you mean like the crank counterweight balancers and/or flywheel balancers used on 'certified' engines? When building a new Corvair, of COURSE a new balancer is used. And have I seen balancers go bad? Of course......after THOUSANDS of miles and many many years of hard use.
And 5000 rpm short bursts? Bogus my friend. Read up on the racing history by Don Yenko and Fitch when those engines were running SCCA races for hours on end.....WITHOUT FAILURE.
But let's for a moment agree that 5500 would destroy the engine: so what would running it at 3,000 do while still making 100 hp or more?
Wynn modifies one of the weak points in Corvairs; that of the distributors. They were originally produced with a single bushing in the distributor which after years of use or extremely hard use at high rpm would allow the distributor shaft to 'walk' and skew timing. Eventually that 'walk' would wear out distributor gears. He modifies the oil pump system, and uses nothing but aircraft carbs WITH CARB HEAT (which is absolutely necessary) Some of the other 'builders' did none of that. But their engines were very pretty on the outside.
And if you try hard enough, there's always the chance something will fail. NOTHING is 100 percent guaranteed. If you don't believe that, ask the poor guys who bought BRAND NEW Lycomings who now have garbage rod end bushings that will facilitate replacing the rods. Or guys like me who have had Lycoming change their oil pump gears three or four times now that forced me to tear into the engine to correct.
William uses redundant ignition, redundant coils, correct baffels, aircraft carbs, aircraft hardware where applicable.
There were 2 or 3 other converters of Corvair engines that used junk parts and questionable techniques and for those I won't speak. But the testing and thoroughness of WW is second to none.
If you search the internet, you'll find MANY Corvair EXPERTS who have never owned one, never run one, and have never torn them apart. I've done all of the above. And like I said in a previous post: I intentionally TRIED to blow up a 150 hp turbo motor (factory setup) by running it wide open until destruction....
And it just kept running.
I've worked on and torn apart just about any aircraft engine you can name (well okay: not a Franklin) and I'm personally convinced that WW's version is as good an engine as any IF it's built to his standards and IF nothing but the best (proven) parts are used. Not junk overseas parts that LOOK great and are a good price or are acceptable for auto use.
Jgibson

[MichaelFarley56]

Thanks for posting Dale!

[lutorm]

I would suspect Sonex’s issue was due only to the Corvair’s weight being beyond the weight limit specified by Sonex. For what it worth, Van’s Aircraft has also warned their builders about using engines that exceed their weight specifications (I.e. people putting IO-540s in RV8s). The weight argument is not just focused on the Corvair but also the O-200. Jeremy Monnett did a webinar on weight and balance which should still be available online at the EAA website where he addresses these issues.

Jake

Ah that makes sense, I was not aware it was heavier than their recommendations.