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Engine Storage Question, Valve Springs & Metal Fatigue

To: John Cowan <jfcowan@earthlink.net>
Subject: Engine Storage Question, Valve Springs & Metal Fatigue
From: Joseph Sholtes <joeiv@concentric.net>
Date: Fri, 13 Feb 1998 17:25:15 -0500
Cc: triumphs@Autox.Team.Net
References: <3.0.16.19980212195829.316f36ee@earthlink.net>
> >Joe IV wrote;

> Carl,(Musson)

> >            ~snip~
> >
> >  If you are likely to store the engine longer, it would be wise to remove
> >the rocker shaft, to aleviate stresses on the valve return springs.

                ~snip~

> > It's a good thing. (Stolen quote, there)
>
> >                                                JOE IV

 John Cowan replied:

> Joe,
>    My TR-3A sat for 28 years. What would the symptom be regarding the valve
> return springs that sat under tension for so long?
>    Thanks.
> John Cowan
>

John,

  Good question.  Maybe my advice is worrying over nothing (GL-4
vrs GL-5, and unleaded fuel come into mind).  But I feel that a fully
compressed valve spring, sitting for years, has got to be weaker than
one that has remained relaxed. Well, realatively relaxed, I mean, there is
still some compression from the retainer.
  As for problems, I guess a spring that's compressed so long would have
less elasticity.  Granted, I'm not a metalurgist- so my advice may be wrong.
But I would venture to say that a weakened spring would lead to valve "float"
at a lower engine speed. I don't think that the metal would be fatigued to the
point of failure, but I wouldn't be surprised if that were the case.
 An immediate, though unlikely, symptom might be that the valve spring would
be so compressed for so long that when it was relased, it would be so short
that the keepers/retainer may fall off, and the valve may drop.  Doomsday pre-
dictions, I know- but who knows?
  With any engine that has sat so long it should be oiled in the cylinders and 
rotated
over slowly by hand a few times before any attempted start, anyway.
                                                        Leaving now, before I 
bum everyone out,
                                           JOE IV
                                           TR 250
                                      WALLINGFORD, CT. USA





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