<VV> Uh....weren't the nitritided cranks only offered in the turbos?

[Tony Underwood]

At 06:28 hours 01/17/2005 -0800, Paul Fox wrote:
>Group,
>           I thought that only the Corsa 140's had the hardened cranks. I
thought that the RB blocks were the ones to look for. All other 140's, PG,
Monza and 500 ones were not hardened.
>            Paul Fox



Humm...  It was my understand (and experience) that the manual gearbox 140s
had nitrided cranks along with PG 140 cranks... until 1967.   The 140 was
kinda limbo'ed in '67 but back again in '68 with the nitrided cranks in
manual gearbox cars only.   The PG cranks after the '66 model year weren't
surface hardened.   

This, told me by a former GM guy who was in a position where he oughta
know...  supposedly.    ;)   

I have a '69 PG 140 in the fleet.   I'm fairly sure it doesn't have a
hardened crank.  At least there's no ampersand on it, haven't tried to
scratch it yet.   There's a '65 140 PG engine here, due to be dismantled to
repair the spun rod.   *It* has a hardened crank... I'm wondering what to
do about the crank, whether to replace it with the good unhardened one I
have or go looking for another hardened one (Guess!).   The two RB (Corsa
140) engines here both have hardened cranks, as do the turbo cranks
(ampersands on them).     

Surface hardening does not keep the crank from getting damaged when a rod
bearing spins.   

It remains my opinion that the surface hardening is so thin that any
material strength advantages are small, if at all.   However, it does make
the cranks extremely hard to scratch; any rocks and gravel drifting around
in the engine oil get embedded in the bearings rather than scratching and
scoring the crank journals.     

That surface hardening is not a deciding criteria when I'm picking around
through crankshafts.   I sure won't turn down a good crank simply because
it's not nitrided.  And, I'm not afraid to put a non-hardened crank in ANY
Vair engine.    


Mr Oughtaknow said that the '68 and '69 140 engines could have had hardened
cranks or not, depending on which shift was assembling the engines.   This
includes the manual gearbox 140 engines (of which there were few in '69) so
the post-66 140 engines are a tossup.   

I'm kinda suspicious.  Would the guys in NY actually be that cavalier about
how they assembled the Vair engines built after '67?   Wouldn't QC remain
the same across the board?   One would think...  

And not to discount Mr Oughtaknow, but does anybody in here know the real
skinny on just what did get a hardened crank after '66, if any?   




tony..