Cool HS pass in a homebuilt AC

[Sonex522]

Shoehorn a big bore Corvair engine into a Sonex airframe, add my pal Dan Weseman as pilot and YEEEEHAAAAAAAA!

http://www.youtube.com/watch?v=Ps3cbICtq_A

Dang it I gotta get mine done.

[Carlo Muro]

Your pal Dan has my full respect.

Excellent!

[Solo Gato]

Holy Crap! too cool

[VonHelm]

Please tell me that stock Corvair fuel pump is just being used as a dust plug.

[Sonex522]

Originally Posted by VonHelm

Please tell me that stock Corvair fuel pump is just being used as a dust plug.

That's Pat Panzera's engine, and it's in use on a test stand and gets demonstrated a lot, so the stock fuel pump works great. It won't fly that way.


The Corvair engine has been flying since the Corvair came out in 1960. Bernie Pietenpol switched from Model A to Corvair power and never looked back.

The Corvair came from the factory with a forged crank and rods. Us airplane guys typically magnaflux, balance, true, etc. etc. the crank, rebuild the rods with ARP bolts, install forged pistons, rebuild the heads, and generally end up with a very smooth, extremely reliable flight engine.

Dan Weseman (the guy in the OP doing the fly by) has developed a 5th bearing set up for the front of the engine which absorbs propeller loads, making the engine even smoother and more bulletproof. I just installed mine, and it's a pretty ingenious piece of engineering - it's a custom casting which replaces the stock bellhousing and features a large plain bearing fed with a -6 oil line.

[I_FLY_LOW]

Damn! Nice work!
What's top speed on her?

[Jack Daniel]

It sure looked to me like it needs a helluva lot'a runway

[dagwood]

Originally Posted by Sonex522

That's Pat Panzera's engine, and it's in use on a test stand and gets demonstrated a lot, so the stock fuel pump works great. It won't fly that way.


The Corvair engine has been flying since the Corvair came out in 1960. Bernie Pietenpol switched from Model A to Corvair power and never looked back.

The Corvair came from the factory with a forged crank and rods. Us airplane guys typically magnaflux, balance, true, etc. etc. the crank, rebuild the rods with ARP bolts, install forged pistons, rebuild the heads, and generally end up with a very smooth, extremely reliable flight engine.

Dan Weseman (the guy in the OP doing the fly by) has developed a 5th bearing set up for the front of the engine which absorbs propeller loads, making the engine even smoother and more bulletproof. I just installed mine, and it's a pretty ingenious piece of engineering - it's a custom casting which replaces the stock bellhousing and features a large plain bearing fed with a -6 oil line.

A friends dad used to make Dual Mag, Dual plug heads for VW mills.

i'm sort of surprised the Corvair hasn't been moded for Dual mag/ plug setup.

[nofate]

Why it the flywheel on the back of some of the motors and on the front in some others?

Is a speed reduction unit used or is it direct drive?

It sure looked fast in the video. Thats a "low" pass for sure. How fast at cruise?

[Sonex522]

Originally Posted by I_FLY_LOW

Damn! Nice work!
What's top speed on her?

About 180 mph straight and level, sustained. The high speed pass was probably around 200 because he could dive into it.

The distributor ignition developed for Corvair flight engines by William Wynne uses a special points plate modified to use two sets of points, or one set of points and a transistorized points replacement module. If the engine starts to run rough because you didn't look at your points in two years, just flip a switch and you get a set of back up points and coil.

Corvairs are small bore, high compression engines. They do not benefit from dual plugs. Redundancy needs are met with a dual point, dual coil system and the fact that it's a six cylinder with much less of a tendency to foul plugs than a Lycoming or Continental type engine.
If you have a problem with breaker points, remember that they have a very low amp draw (nice when the alternator craps out), they fail with lots of warning, they do not rely on any microchips or circuit boards to do their job, and they can be easily inspected by eyeball. Besides, mags have points, right?

[Sonex522]

Originally Posted by Jack Daniel

It sure looked to me like it needs a helluva lot'a runway

Yeah. It takes about 350 feet of grass strip to get airborne. What a bummer.

The Sonex is one of the few airplanes with a 4:1 speed ratio on 120 hp. Stalls at 40 mph and over 165 top speed. I've personally witnessed it from the right seat. Not a brochure figure.

[biggziff]

We have 2 Sonerai IILs at the local field. They're VW powered and a lot of fun for the $$. I have the frame all welded up and all the misc bits, but not much time to work on it. Pity...Great aircraft.

[Sonex522]

Originally Posted by nofate

Why it the flywheel on the back of some of the motors and on the front in some others?

Is a speed reduction unit used or is it direct drive?

It sure looked fast in the video. Thats a "low" pass for sure. How fast at cruise?

The flywheel in the pics is actually just the starter ring gear/flex plate. Some guys use rear starters, but front starters are more common and easier to set up.

Direct drive works best. A Rinker drive was developed for Corvair engines using the gear box from the rear axle unit from a VW bus, but it just added a ton of weight, reduced reliability and added no performance.

[Sonex522]

Originally Posted by biggziff

We have 2 Sonerai IILs at the local field. They're VW powered and a lot of fun for the $$. I have the frame all welded up and all the misc bits, but not much time to work on it. Pity...Great aircraft.

Someday I want a Sonerai I with an Aerovee in it. I'd love a Cassutt with a 'Vair, but I'm too chicken.

[LowandSlo]

This one's better.
(bit of NSFW language at the end)
http://