The "stress release" you are talking about is a well understood phenomanom.
What is occuring is the realignment of the crystal structure of the metal in
the item. It is also called "work hardening." Gun barrel makers have
understood this for years. To make the best barrels, once the barrel was
made, it would be dropped on a hard surface, or hit with a heavy hammer a few
times. Then the final alignment would be done. But this was also risky, in
that the barrel might be ruined. Not generally done, and the process of
"warming" a barrel during a competition served the purpose of releasing the
internal stresses for the duration. Shooting with a cold barrel, the point of
aim will shift as the barrel warms, so you would need to reaim the gun after
each shot. Not good in competition.
________________________________________
From: 6pack-bounces+jar7u=hscmail.mcc.virginia.edu@autox.team.net
[6pack-bounces+jar7u=hscmail.mcc.virginia.edu@autox.team.net] On Behalf Of
Navarrette, Vance [vance.navarrette@intel.com]
Sent: Thursday, September 11, 2008 4:53 PM
To: Kendall Larsen; 6pack List
Subject: Re: [6pack] New Engine AUTOpsy
Kendall:
I believe the claim is that residual stresses in the crank relax over
time, so older is better. It also may be that the thermal cycling increases
the rate of relaxation (Any metallurgists out there?).
I would hazard a guess that even a NOS crank has had plenty of time
to
relax, thermal cycling or not. The newest crank you could get now would be 30
years old, so it is probably well relaxed. If not, give it a beer to drink
and
it will relax. It always works for me.
Vance
Vance Navarrette
Cogito Ergo Zoom
I think, therefore I go fast
-----Original Message-----
From: 6pack-bounces+vance.navarrette=intel.com@autox.team.net
[mailto:6pack-bounces+vance.navarrette=intel.com@autox.team.net] On Behalf Of
Kendall Larsen
Sent: Thursday, September 11, 2008 1:13 PM
To: Robert Lang; 6pack List
Subject: Re: [6pack] New Engine AUTOpsy
Hi Robert,
>I agree with Vance - it'll cost more to fix the crank than to
get another
>servicable used or new (my pref. is NOS) crank. They are def.
available
>from various sources.
I thought I'd heard before, (possibly from
you?) that a used crank was better than NOS because they were better if they
had been used for awhile.
Mine crank was already 0.010 under so yes, it is
definitely scrap.
Kendall
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