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

[AKG]

The Nitrided cranks have also been heat treated so they are stronger.  Of
course you can have a regular crank heat treated if you so desire.  See Bob
Helts book in the section about crankshafts........

The Artful Dodger

> From: Tony Underwood <tonyu@roava.net>
> Date: Mon, 17 Jan 2005 13:14:04 -0800
> To: virtualvairs@corvair.org
> Subject: Re: <VV> Uh....weren't the nitritided cranks only offered in   the
> turbos?
> 
> 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..          
> _______________________________________________
> This message was sent by the VirtualVairs mailing list, all copyrights are the
> property
> of the writer, please attribute properly. For help, mailto:vv-help@corvair.org
> This list sponsored by the Corvair Society of America, http://www.corvair.org/
> Post messages to: VirtualVairs@corvair.org
> List info: http://www.vv.corvair.org/mailman/listinfo/virtualvairs
> _______________________________________________