Re: Advice on 392 rebuild

[jlandry@domain.elided (John A. Landry)]

In Linda Tripp's secret telephone recording, Monica and Roger Scow
<rscow@domain.elided> were heard saying...

>Do I need to go with oversized rings for cylinders that are .007" out?  I
>don't think I'll need oversized pistons...and don't plan to bore the block.
>I haven't ordered anything yet.

If you don't bore the cylinders oversize, then no... you'd go with standard
rings and pistons because I don't think slight oversizes are available for the
IH... but be sure and ask Northern what they list.   The maximum standard
cylinder size for the 392 is 4.1270", so how much over that are you talking
about... the full .007"?  That's quite a bit and you're going to need to make
sure the end gap on the standard rings are within tolerance, which is .013" to
.023" on the 392.  Obviously the goal is to try and keep everything within
tolerances as close as possible.  The key thing with the cylinders is the
piston to cylinder fit.  If you have old pistons with worn skirts and worn
cylinders, then very likely you'll have excessive piston to cylinder wall
clearance.  This leads to piston slap noises as the piston rocks back and
forth in the cylinder.  The IH shop manual shows the procedure for checking
the piston to cylinder clearance.  If it's excessive, then you really have no
choice but to buy new oversize pistons and rebore the cylinders... which is
really the best thing to do in the long run anyway.

>Item #  Desc               Price     Core
>176710  78 Intl Harvester 2816.89  1100.00

Ouch!

Regards,

John L.
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