Corvair - General Info

[lutorm]

Is the flycorvair.com website down for anyone else? I'm getting a "This domain has temporarily been disabled.
To restore the domain, contact your Customer Support." message.

[lstinthot]

I am getting the same message at www.flycorvair.com. www.flycorvair.net is working.

[Jgibson]

Differences including: (on the WW version)
Better prop flange retention.
Better parts (other than the VW jugs). (Most VW parts made in China.)
MUCH better strength with the new fifth bearing setup.
Designed by GM to make high hp at 5500 rpm, so running it at 3k is no stress.
As stated: heads expected to tolerate 525 degrees in auto version.
120 hp model makes same hp on FIVE cylinders as an O-200 does on four.
Specifically modified oil pump.
3.3 version is lighter than an O-200 because of new forged, stroked crank and rods.
William Wynn has dedicated his life to Corvair power and has tested relentlessly. He isn't afraid to admit mistakes and change course, is willing to share knowledge with any one willing to listen. He and Dan Weseman have fully supported builders of MANY types of aircraft and quite a few are (and have been) flying successfully on the Zenith family of planes. Zenith factory fully embraced his engines and builders of those planes have benefited greatly with complete firewall forward packages including virtually everything necessary to install and fly the Corvair engine safely.
But as with ANY engine, the Corvair MUST be flown and maintained in accordance with proven methods. And William has spelled it all out in his manuals.
The stock VW was NEVER designed to run at higher (aircraft) rpm's for prolonged period of times. The average rebuild times of VW's is quite low compared to the Corvair. I personally TRIED to blow up a turbo Corvair without success and ran a naturally aspirated version for close to 100k miles in high rpm racing situations without a failure EVER. Did it leak oil at the pushrod tubes? Sure did! But the new O ring material solves that.
IMHO you can't go wrong with the additional horsepower and reliability of a William Wynn Corvair.

[GordonTurner]

I found, disassembled and cleaned the core and took it to a Corvair College. William did the bulk of the work from that point, completing it with me at Dan Weseman’s shop. I looked at Williams operation carefully before diving in. Each piece of the engine has been selected based on tested performance, then sourced from reliable (American) manufacturers. As was stated, the aircraft engine derived from the Corvair auto engine is being run at significantly reduced rpm pressure and temperatures. I’m happy with my choice and looking forward to operating it.

William and Dan are now offering the engine as a complete kit. If you’re interested in building but hesitant to go scrounge parts from varied sources this is a good solution. And the CC’s are a really great chance to get your hands dirty, learn about motors, have sharp eyes looking over your shoulder, and meet fellow aviators. Highly recommend.

Gordon

[RodgerC]

Has anyone first hand experience with the Azalea Aviation Corvair product?

[daleandee]

As always I'm a bit hesitant to show how impassioned I can be over the Corvair engine on my aircraft as it is not my intention to irritate the factory nor show any disrespect to any other builder on his choice of power plant for their aircraft. Yet, so far, this discussion seems to be quite civil. As such I wanted to echo what others have said and give you the reasons I find the Corvair engine to be worth considering.

In the November 2014 edition of the Sonex Builders & Pilots Foundation newsletter I wrote an article called "Why a Sonex? Why a Corvair?" that starts on page 13. http://www.sonexfoundation.com/uploads/November_2014.pdf I gave how I came to the Corvair but didn't get into the particulars of why I find this engine to be an exceptional choice. Some of the reasons given below have already been noted by others.

I can only speak to the Corvair conversion as it comes from William Wynne & Dan Weseman.


20 reasons to contemplate using a Corvair engine :

1) Mounting - Solid bed mount that eliminates sagging/drooping. Energy Suspension Part No. 9.8105RC bushings are durable, easily sourced, and current cost is about ten bucks for a full set.

2) Ignition - GM designed distributor with high quality Echlin cap & rotor. Upgraded William Wynne distributor includes dual shaft bearings & a heavier lock pin for the glued in place drive gear. New internal electronics include one electronic ignition module & one set of points. Ignition timing advances with RPM and is set using a standard automotive timing light.

3) Fuel – Gravity fed, & delivered via an “aircraft carb” by Marvel Schebler and certified for flight use on O-200 engines. Recommended version (MA3-SPA) has primer & mixture. Carb heat is required.

4) Other carb choices are available and slide carbs have been used. Some carbs may require a fuel pump and carb heat box.

5) Intake – long runs to increase low end torque into the factory designed intake means good, even fuel distribution. Intake has a proper carb flange for carb to be bolted to the intake manifold.

6) Exhaust – lightweight 3 into 1 straight pipes on each side. Exhaust exit the bottom of the head and do not interfere with the cooling baffles or the cowling.

7) Cross flow designed heads – provide better flow for getting the fuel in and the exhaust gases out. Makes aircraft conversion easier & much more practical.

8) Canted valves – Setting up the cylinder for better breathing & mixture control, more even fuel burn, and easier exhaust gas exit.

9) Hydraulic lifters – Set ‘em and forget ‘em for the life of the engine. Some say valve condition is better known by “checking the gap” but a pull through on preflight, differential compression test, or borescope will give this info and does not require the removal of the valve cover.

10) No head cracking between valves – this is a real concern on big valve VW heads. Not so with the Corvair.

11) Dual fuel pistons that allow the use of 100LL or 93 Mogas (Timing may need to be reset for 93 oct).

12) Robust – designed for up to 5600 RPM & 180 HP the engine is not strained at 2800 RPM giving 90 HP (3.0) for continuous flight. Prop limits WOT on flight engines to about 3400-3500 RPM and rev limiter on electronic ignition is set at 4K.

13) Cooling – Heads designed to take a CHT limit of 575ºF in automotive use are set much lower for flight motors and typically run at 325-350ºF (over 400ºF is rare). In the Cleanex airframe CHTs are in the 250-275ºF range during summer cruise flight.

14) Oil Temp – On the Cleanex airframe the OT (with stock GM cooler) is 180-220ºF in cruise flight. Normal summer temps show 205ºF and winter will be lower. Very hot summer days will sometimes see 220ºF. Larger coolers are available if needed.

15) Integrated head/intake manifold means less connections and possible leaks. Also gives better fuel distribution to cylinders than individual aftermarket runners/connectors.

16) An additional safety shaft that is threaded into the crank to assure retention of propeller hub.

17) Oil fed 5th bearing for prop loads that protects the crank from bending/breakage. A GM geared, high volume, one piece housing, oil pump used on 5th bearing engines.

18) Smoothness – six cylinder engines are inherently smooth and a well-built Corvair is extremely smooth with little vibration which adds life to the air frame.

19) Part availability – With so many built by GM (1.8 million) parts are easily sourced. Flight engines can be built with almost all new parts. Core parts are heads, engine case, distributor body, and rear oil pump assembly cover.

20) Several displacements available – 100, 110, 120, & 125 horsepower (stroker) versions are available.

So there you have it. I hope this helps those that are need of more information in the decision making process. FWIW ... Yes I would do it the same way again!

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

[dbdevkc]

I’m on Long Island, building my Waiex. Can’t give you a flight report, thats a ways away, but my motor is ready to go, installed in the coffee table for the time being. Have also the motor mount, nosebowl, baffles, intakes and exhaust, most of the firewall forward that you can get from WW. The process with WW took awhile, but he has teamed up with Dan Weseman of Panther and streamlined the process hugely. Happy to talk if you want, or show amd tell if you want to visit.

Best of luck, Gordon

I would love to take you up on that offer if possible. I'd love to see it. I'm up in Orange County (Stewart Airport area). I had made up my mind to go Corvair a year or two ago, have the WW manual and have unsuccessfully been trying to source a motor locally.

Kevin

[DCASonex]

I think the Corvair engine itself was derived from one designed for helicopter use, and thus intended to put out high power for extended periods of time as is also needed on airplanes, unlike automobile engines of which the VW is included. High heat dissipation from the heads is one aspect of that. If I did not have a CAMit engine that was running well, a Corvair conversion would be high on my list

David A.

[GordonTurner]

Hi Kevin

You’re more than welcome. Let me know if you’re down this way.

Gordon

[SonexN76ET]

I am curious. Has anyone taken their Corvair powered aircraft on really long cross country flights? Such as the flight Aaron made in his Jabiru 3300 Sonex from Massachusetts to Alaska and the Bahamas? Or Kip’s flights to 48 states in his Jab 3300 Waiex? Or Gary’s VW Sonex from Colorado to Key West? Or my Aerovee Sonex flights from South Florida up to the Canadian border in Minnesota? How many Corvair powered aircraft have more than 500 hours on them? I only ask because these stories have not been shared here.

Thanks,

Jake