Did the crank bind after you torqued all the main caps or just one main cap?
(meaning find out which specific cap it is) Find a factory manual for your
year engine (is it a real '54 261 or a transplant? Use the casting date code
or casting number to tell you) to get the specs. The rear cap may have it's
own spec. If the plastigage reads fine (I'm guessing you're at 0.0015 or
0.0020) and you get binding on only one cap, there's something strange with
1) the journal, 2) the bearing, 3) the way you have installed the bearing,
or 4) the main cap. Carefully inspect each of these to see if you can
visually isolate the problem. Measure each separately if you have to (in
several locations to check clearance, taper and out of round). Has the
crank been recently ground? Did you line bore the mains? (not suggesting
you do either) I've seen a lot of screw-ups come back from the machinist.
You might try plastigaging the fit with the crankshaft in two positions, 90
degrees apart.
Good luck! Let us know what you find out so we can all learn.
Allen in Seattle
----- Original Message -----
From: <SnotMe80@aol.com>
To: <oletrucks@autox.team.net>
Sent: Saturday, February 01, 2003 11:22 AM
Subject: [oletrucks] Need help with 261 engine specs-ASAP-please help
> me and my dad are rebuilding our 261 out of our 54. we are tighting down
the
> main bearing caps-the book says to check with plastigauge and torque down
to
> 100-110 ft lbs which we did at a 100. the plastigauge checked out fine but
if
> we leave it at 100 the crank will not turn over at all. if we only torque
> down to 90 it spins just fine? what is the correct torque spec for this?
we
> can't go any further till we figure this out? thanks abunch
> Rob
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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