<VV> Corvair crank failure - at 4300 feet

[Tony Underwood]

At 10:53 AM 3/1/2007, Chris & Bill Strickland wrote:
>I don't recall this item showing up back during the broken crank / 
>nitriding discussions -- sorta interesting
>
>     http://home.hiwaay.net/~langford/corvair/flexplate/problem.html



This is a good example of the logic in using a reduction gear drive 
and the resulting escape from the *immense* amount of crank loading 
that you have to deal with if you run a prop bolted directly to the crank.


All you need do is look at the crank in a Continental or Lycoming 
boxer-6 aero engine and check that front hub and main bearing 
journal.   It's huge.

http://www.superiorairparts.com/Images/PiecePartsPhotoGallery/Crankshaft/62.jpeg 



The reduction gear drive absorbs all the different loading stresses 
that the prop presents.   No flexing of the crank.   It also allows 
you to buzz the engine a bit, into its most efficient rpm range which 
in a 'Vair engine is certainly gonna be higher than the most 
efficient rpm for a prop.


...the problem is the cost of these reduction gear drives...   X;{


Does anybody still make a reduction drive for a Corvair engine?


tony..