Corvair conversion engines

As my research continues, I have been investigating possible engines for
a 601XL. The Corvair engines looked like a good candidate. The reports
seemed very good and the engine was surprisingly inexpensive for initial
purchase and long-term maintenance.

The stated expected TBO is 1500 hours and the Corvair Authority website
documents the use of a Corvair engine in a 601XL.

Everything seemed OK until yesterday when I read the most recent updates
on their website. Seems that the "untreated" automotive cranks have
been cracking in a very short time. Nitriding seems like the only
solution. But with standard cranks cracking at under 100 hours, what
would be the expected life of a nitrided crank. Twice as long, four
times as long, eight times as long? This would still fall short of the
1500 hour TBO stated by the Corvair Authority.

Does anyone have any first hand experience with Corvair conversion
engines? Any info on their realistic life and reliability?

TIA,

CV

Cal Vanize wrote:

As my research continues, I have been investigating possible engines for
a 601XL. The Corvair engines looked like a good candidate. The reports
seemed very good and the engine was surprisingly inexpensive for initial
purchase and long-term maintenance.

The stated expected TBO is 1500 hours and the Corvair Authority website
documents the use of a Corvair engine in a 601XL.

Everything seemed OK until yesterday when I read the most recent updates
on their website. Seems that the "untreated" automotive cranks have
been cracking in a very short time. Nitriding seems like the only
solution. But with standard cranks cracking at under 100 hours, what
would be the expected life of a nitrided crank. Twice as long, four
times as long, eight times as long? This would still fall short of the
1500 hour TBO stated by the Corvair Authority.

Does anyone have any first hand experience with Corvair conversion
engines? Any info on their realistic life and reliability?

TIA,

CV


Welcome to the real world of auto engine conversions, Cal.

I have never flown a Corvair, and of them only by reputation, so I'm
not much help with your crank problem.

I've flown several VW conversions, a couple of Subarus, and one Chevy
V6 in an RV-6, so I don't claim to be an expert, just another
experienced fool.

The Great Plains crank for my 2180cc VW is a massive chunk of steel.

It bears no resemblance the the auto market cranks I've ever seen.
But then auto motors _usually_ don't have to deal with propeller
loads... (if that helps?)


My ex-next-door-neighbor built a 601-HDS with a Rotax 912 and a 74"?
electric Ivo prop for power. Now that is a sweet setup.
He has over a hundred hours on it now and only has to feed it gas and
change the oil (and electric prop bushings).

His airplane is heavy - with every conceivable gadget to play with.
But the little Rotax just ignores it and slings the airplane into the
sky anyway.

Other than a minor problem with the oil tank plumbing (I saw the
"instructions" and yes they are ambiguous at best...) that caused the
oil temp to track the airspeed indicator on the first taxi runs, the
engine has performed smoothly and flawlessly.
Every time.

That's something I really like in an airplane motor...

Richard

Do you have a link for the broken cranks? I cannot find anything about
broken cranks on the "Corvair authority" site.

http://www.flycorvair.com/

I did find the following statement:

"I have never seen a cracked head, cylinder, case, crank or rod in the
hundreds of Corvair engines I have inspected. It is a very strong engine."

The Corvair engine has been flying since the early 1960's. Seems odd that
ANY flaw would only now be being discovered.






Everything seemed OK until yesterday when I read the most recent updates
on their website. Seems that the "untreated" automotive cranks have been
cracking in a very short time. Nitriding seems like the only solution.
But with standard cranks cracking at under 100 hours, what would be the
expected life of a nitrided crank. Twice as long, four times as long,
eight times as long? This would still fall short of the 1500 hour TBO
stated by the Corvair Authority.

Does anyone have any first hand experience with Corvair conversion
engines? Any info on their realistic life and reliability?

TIA,

CV

"Ron Webb" wrote in
:

Do you have a link for the broken cranks? I cannot find anything about
broken cranks on the "Corvair authority" site.

http://www.flycorvair.com/


Click on the "Important Research Update" link for the whole story...

--
-- ET :-)

"A common mistake people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools."---- Douglas Adams

See: http://www.flycorvair.com/crankissues.html


"Ron Webb" wrote in message ...
Do you have a link for the broken cranks? I cannot find anything about broken cranks on the "Corvair authority" site.

http://www.flycorvair.com/

I did find the following statement:

"I have never seen a cracked head, cylinder, case, crank or rod in the hundreds of Corvair engines I have inspected. It is a very
strong engine."

The Corvair engine has been flying since the early 1960's. Seems odd that ANY flaw would only now be being discovered.






Everything seemed OK until yesterday when I read the most recent updates on their website. Seems that the "untreated" automotive
cranks have been cracking in a very short time. Nitriding seems like the only solution. But with standard cranks cracking at
under 100 hours, what would be the expected life of a nitrided crank. Twice as long, four times as long, eight times as long?
This would still fall short of the 1500 hour TBO stated by the Corvair Authority.

Does anyone have any first hand experience with Corvair conversion engines? Any info on their realistic life and reliability?

TIA,

CV

On Wed, 18 Jan 2006 21:26:23 GMT, "Don Lewis n FTW"
wrote:


See: http://www.flycorvair.com/crankissues.html


"Ron Webb" wrote in message ...
Do you have a link for the broken cranks? I cannot find anything about broken cranks on the "Corvair authority" site.

http://www.flycorvair.com/

I did find the following statement:

"I have never seen a cracked head, cylinder, case, crank or rod in the hundreds of Corvair engines I have inspected. It is a very
strong engine."

The Corvair engine has been flying since the early 1960's. Seems odd that ANY flaw would only now be being discovered.



They are only recently flying at 115HP in 200MPH planes - which is a
totally new world. Previous engines were flying at 60HP and 90MPH
without any issues.




Everything seemed OK until yesterday when I read the most recent updates on their website. Seems that the "untreated" automotive
cranks have been cracking in a very short time. Nitriding seems like the only solution. But with standard cranks cracking at
under 100 hours, what would be the expected life of a nitrided crank. Twice as long, four times as long, eight times as long?
This would still fall short of the 1500 hour TBO stated by the Corvair Authority.

Does anyone have any first hand experience with Corvair conversion engines? Any info on their realistic life and reliability?

TIA,

CV

clare at snyder.on.ca wrote in message
news
On Wed, 18 Jan 2006 21:26:23 GMT, "Don Lewis n FTW"
wrote:


See: http://www.flycorvair.com/crankissues.html


"Ron Webb" wrote in message
...
Do you have a link for the broken cranks? I cannot find anything about
broken cranks on the "Corvair authority" site.

http://www.flycorvair.com/

I did find the following statement:

"I have never seen a cracked head, cylinder, case, crank or rod in the
hundreds of Corvair engines I have inspected. It is a very
strong engine."

The Corvair engine has been flying since the early 1960's. Seems odd
that ANY flaw would only now be being discovered.



They are only recently flying at 115HP in 200MPH planes - which is a
totally new world. Previous engines were flying at 60HP and 90MPH
without any issues.

Interesting. I had assumed they were originally flying with 80HP or less,
but had no idea it was that much less. Thanks.





Everything seemed OK until yesterday when I read the most recent
updates on their website. Seems that the "untreated" automotive
cranks have been cracking in a very short time. Nitriding seems like
the only solution. But with standard cranks cracking at
under 100 hours, what would be the expected life of a nitrided crank.
Twice as long, four times as long, eight times as long?
This would still fall short of the 1500 hour TBO stated by the Corvair
Authority.

Does anyone have any first hand experience with Corvair conversion
engines? Any info on their realistic life and reliability?

TIA,

CV

"Peter Dohm" wrote

Interesting. I had assumed they were originally flying with 80HP or less,
but had no idea it was that much less. Thanks.

You could find many people that would argue that low of a HP figure. I
think your 80 is closer, and in might be a few more than that.
--
Jim in NC

The issue us addressed in this page:

http://www.flycorvair.com/crankissues.html

The date on the page is 15 January 2006 - just released information.



Ron Webb wrote:

Do you have a link for the broken cranks? I cannot find anything about
broken cranks on the "Corvair authority" site.

http://www.flycorvair.com/

I did find the following statement:

"I have never seen a cracked head, cylinder, case, crank or rod in the
hundreds of Corvair engines I have inspected. It is a very strong engine."

The Corvair engine has been flying since the early 1960's. Seems odd that
ANY flaw would only now be being discovered.







Everything seemed OK until yesterday when I read the most recent updates
on their website. Seems that the "untreated" automotive cranks have been
cracking in a very short time. Nitriding seems like the only solution.
But with standard cranks cracking at under 100 hours, what would be the
expected life of a nitrided crank. Twice as long, four times as long,
eight times as long? This would still fall short of the 1500 hour TBO
stated by the Corvair Authority.

Does anyone have any first hand experience with Corvair conversion
engines? Any info on their realistic life and reliability?

TIA,

CV

Cal Vanize wrote:

The issue us addressed in this page:

http://www.flycorvair.com/crankissues.html

The date on the page is 15 January 2006 - just released information.



Ron Webb wrote:

Do you have a link for the broken cranks? I cannot find anything about
broken cranks on the "Corvair authority" site.

http://www.flycorvair.com/

I did find the following statement:

"I have never seen a cracked head, cylinder, case, crank or rod in the
hundreds of Corvair engines I have inspected. It is a very strong
engine."

The Corvair engine has been flying since the early 1960's. Seems odd
that ANY flaw would only now be being discovered.





that dose seem like a lot of broken cranks...