Tom,
When you spin a rod bearing, the rod has been deformed and is no longer round
at the very least. Tyupically the crank also has taken damage with material
transfer and always needs attention, if it's even usable. You put the rest of
the engine at risk by trying to just replace bearings.
At the very least the crank must be sized and repaired and the rod will need to
be trued if it can be saved. Rods tend to get egg shaped due to the vectors of
force and the weaker areas stretching. The discoloration typical in this
situation will be an indicator of how hot things got during the failure. Also
check to make sure during the failure, the piston didn't smack the head which
may have crushed the upper ring lands, cracked the piston or damaged a valve
depending on clearances. This is caused by the piston being able to travel
beyond it's normal TDC position due to the reduced class of fit on the bearing
surface.
I have bearings for both MGBs and the TR-6/1500 applications but it would be
doing you no favor to send them. If you're lucky you can repair what you
currently have in terms of damage and not create more. The quick fix here might
reduce the engine to scrap in a matter of minutes.
Can you contact me offline? I wouldn't mind the replacement of the bits that
kept you going back at the Mosport event.
Thanks
Russ Moore
-----Original Message-----
From: tom strange <tstrange@sbcglobal.net>
Sent: Aug 30, 2005 1:51 AM
To: fot@autox.team.net
Subject: bearing help...
Help, I need some words of wisdom here...
I have a spit 1500 that wants to run one more race this season. We just spun
a rod bearing in it & I need a replacement. We normally run the MG bearing as
it is slightly wider, However..... I dont have an mg style bearing in stock
for the replacement. I do have a set of bearings (standards) for a GT6. I
believe this is the same as a stock rod bearing for the 1500 spit.
The one I do have in stock is an ACL bearing & not as reliable as some, but
what do you all think. If I use it, will it last 2 hours of run time?????
I really dont want to have an engine failure for this person.... but I cant
see this bearing failing in the amount of time we want to run it. the engine
will get a complete refresh after this race, over the winter.
Opinions????????????????
Tom
http://www.fot-racing.com/spit/caption/tom_strange.htm
#4 white spitfire
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