<VV> CRANkCASE PARTS

[Tony Underwood]

At 02:00 PM 1/23/2010, Larry Forman wrote:
>Tony,
>I have had trouble with low idle oil pressure on several Corvair engines.
>I am thinking it might be due to cam bore wear.


Oil pump rotors wear as well, popular low pressure cause.


>So please tell us what to look for since I have not started doing this.
>Is it the cam gear end?


There *is* more wear potential on the gear end.


>Are there obvious wear burnishing marks or ??


Yep.   I've stared at a few split crankcases along the way and a 
respectable unworn factory cut cam bore has a "look" to it that a 
bore worn by a cam journal does not.   The bores with low wear will 
have polish marks alongside what will appear to be the factory bore 
cut.   The cam will have burnished the "high spots" in the factory 
bore cuts.   The polished burnished spots won't occupy the entire 
bore in good crankcases... a worn cam bore won't be showing much if 
any of the factory bore cut.

It's still possible that a cam bore showing burnishing around the 
entire bore surface could still be serviceable... but it should be 
checked out if it shows this sort of wear.   If the bores show 
evidence of the original factory cut throughout each bore's entire 
circumference I'd wager the crankcase would be fine.

Still... a mic is your buddy.


tony..