Corvair Engine

[johnb]

Good job. I'm considering Corvair for my LSA, but have a long way to go on airframe first.

[davzLSA]

Hi Jimmy congratulations on your engine run in Florida. I ran my engine there too for the first time. Its sitting in a box in my house waiting on me to get my LSA air frame built. I think William and Dan are great guys and a pleasure to work with. I look forward to seeing your progress on this forum. I will be posting my progress as well. Im starting a LSA 2.0. The first one was not welded by me to aviation standards, I intend to fix that on the second fuse.

[bcbearhawkLSA]

Hi Jimmy,
Congratulations on your engine run! REALLY looking forward to hear about the performance of the LSA with it. I am still chipping away on mine here, cleaning, more cleaning...

[davzLSA]

Hey Guys, if you are interested, William Wynne has started a new youtube channel, https://www.youtube.com/channel/UCtg...WV7NoSEHNzpHwQ a great source of info on the Corvair engine.

[bcbearhawkLSA]

Good Morning,
I have downloaded and read through Bill’s Teardown Manual, which is free by the way, and found it to be to super helpful and in some ways better as it is very sanitized and to the point of what you as the builder can do. Couple other things I like is the weight distribution of the accessories and the “No Belts” set up on his engine. Check it out!

[davzLSA]

I like their 5th bearing, it looks like a continental bearing.

[Cameron Ramsey]

Hey dave, did I read that you built the 3000cc corvair with the 8409 crank and it made 120 hp? I thought you had to build the 3.3 to get 120hp. Is that wrong?

[davzLSA]

Hi Cameron, That is what I was told when I started the engine, I dont really expect to get that much power out of it, I think it will be a solid 100HP at a decent RPM. At this point it is all speculation because I have not had the engine dyno;d I think I will know for sure when I get my plane flying. I think it was advertised as 120, we'll see. But hey its painted red and has big120HP stickers on the valve covers!!!

[Cameron Ramsey]

I saw the pictures. It is a sharp looking engine!!

[davzLSA]

Maybe If I can get the rest of the plane looking that sharp I will have accomplished something?

[Papa Foxtrot]

An FYI, there was another inflight failure of a Corvair conversion this past weekend. The KR2 made a "hard landing" in a cornfield and ended up on it's back. The pilot/owner had minor injuries and walked away. No idea yet what caused the failure, but the owner had complained of oil leaking from the 5th bearing seal and planned to replace it. His timeline for the NTSB:

1550: Aircraft departed KFEP RWY 6 after normal preflight and runup as per aircraft checklist.
1551: Climbout was normal to 2200 ft MSL. Flight proceeded direct to C77 (Poplar Grove)
1558: Decended to 1900MSL to avoid KRFD TRSA outer ring.
1605: Entered 45 angle for left downwind for RWY 30 at C77
1609: Landed C77. taxi to parking and shutdown engine
1649: Engine start for departure back to KFEP via RWY 30
1651: End of runway check completed. Runup normal no problems noted.
1653: Climbout from Rwy 30 normal for first 60 sec
1654: Noted aircraft not accellerating when nose lowered at full power. First hint of oil smoke in cockpit.
1654.15 Scan revealled a lower than normal oil pressure of 35 psi. (This engine has always had 40-45 psi oil pressure) Oil smoke started to thicken. Scan also revealed that the oil temp was climbing. 220f max has been noted during previous climbouts. Oil temp was ~230f
1655 I lowered the nose to get more ram air cooling. This had no effect and smoke seemed to be getting worse
1656: Made radio call declaring I had oil pressure problems and was returning to the airport. Started left 180 turn at 658ft AGL.
1656.30 Completed turn @ 563 ft AGL and could hear engine loosing power. Scanning for C77 runway 12 revealed mostly trees between my position and the runway. I determined that I would not make the runway. I looked to my left and picked out my landing field.
1656.45 I made another radio call announcing my intensions to land in a corn field 2 miles west of C77. With the engine still running I setup for an E to W landing into the prevailing wind.
1657. I made my final turn for landing at 327ft AGL. I deployed my speed brake landed hard with (~1000ft) 50% of the field remaining. I bounced back into the air and held aft stick waiting for the aircraft to settle. It did settle and rolled about 100ft before the nosewheel dug into the soft ground and the aircraft flipped forward and over onto its back. The canopy shattered however the turtledeck remained intack enough allowing me to exit under the upper left longeron.

Local news coverage.

FWIW, the owner has commented that "if" he rebuilds the plane, it will not be with a Corvair engine.

[davzLSA]

Thanks for that update on the Corvair Engine, I hope you will let us know when any airplane with a continental or lycoming engine crashes too?

[davzLSA]

I have to question the soundness of a decision for someone even attempting a flight with a known engine problem too? MMM I think that would apply to ANY engine?

[Papa Foxtrot]

If you never flew an airplane with an oil leak, you'd likely never fly an airplane.

[jaredyates]

Let's keep it civil please. All powerplant choices have advantages and disadvantages, and all can fail. Choose the one that best suits your needs and come here to talk about how to make it as reliable as possible. This brings more value than crusading for or against one selection.

[Cameron Ramsey]

The name stamped on the side of an engine is not what makes it reliable. Oil leaking from a bearing is not got going to cause low oil pressure (unless it leaked enough to have a low volume of oil). It sounds like an oil passageway became clogged or the oil level wasn’t checked before the second takeoff. The corvair is no different than a continental or lycoming. Its a case and a crank with air cooled cylinders and gears that mesh together to force oil through the engine. While companies that use good components in their engines usually do develop good reputations, we all know they can fail. I guess my point here is, as pilots we need to make sure and not get lulled into a false sense of security with our powerplants because of the name stamped on them and, remember that loss of oil pressure has happened in at least one engine made by EVERY company at some time or another. So......keep up with your engine maintenance, do good preflights and make flying as safe as it can be!

[davzLSA]

Hi Cameron that is one reason why WW advocates a cowl top that can be removed and one can see the whole engine for a more through inspection for the pre flight. I think that's a good idea for any engine like you said. I intend to have that facility with the cowl im going to build for my LSA. Safety begins and ends with the guy in the left seat?

[Cameron Ramsey]

Hey dave, I would like to go through the engine and see what happened. That’s just how my brain works. I have read and re-read the account that was posted and it sounds like an oil line may have ruptured. That would explain a normal run up, then at the high power setting during takeoff, oil was being spewed out causing lower oil pressure and smoke in the cockpit and then, the engine was starved of oil all together and locked up. Of course, thats just my hypothesis from limited information.

[davzLSA]

Hi Cameron, I would be interested also in the exact cause of the failure, there is always something to be learned in every failure. But I do not think it was anything fundamental to the design of the engine its self, there are too many of them flying successfully for too many hours for anything fundamentally to be a problem.