D Wade wrote:
> I blew out a piston a couple of months ago in my 77 MGB and started this
> morning to put it back together. Here's the problem. The pistons were
> .040 and the rod bearings were .010. This was stamped on the old parts.
> I've got a new set of pistons and rod bearings and so the first thing I
did
> was slip one piston down into the engine, with no rings on it, and put on
> the rod cap. When I tightened it up, it I couldn't turn the engine any
> more. It was tight! Any suggestions as to what to try next?
When you say you "blew out a piston" was there any other damage? Were the
rods and caps kept carefully in sets as original? They can not be mixed. The
big ends should have been sized by a competent machine shop. That means the
cap is bolted to the rod, and machined as required to ensure a perfect
diameter.
Were the crank journals checked and / or machined as required to a perfect
diameter and finish? Besides perfect diameter, the finish of the journal
surface should be such that your finger nail should not be able to detect
any grooves in the surface. Otherwise the crank should be turned as
required.
Bottom line is, I suspect either the rods and caps were mixed up somehow, or
the new bearing shells are not the right size, or there is out of round of
the big end assembly.
Hope these hints will help.
Rich Chrysler
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