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Re: [oletrucks] Rod Bearings

To: Advdesign1@aol.com, oletrucks@autox.team.net
Subject: Re: [oletrucks] Rod Bearings
From: Passnb4U@aol.com
Date: Fri, 28 Jan 2000 10:59:54 EST
In a message dated 1/28/00 3:54:54 AM Pacific Standard Time, 
Advdesign1@aol.com writes:

> I have a 216 that knocks on #3 rod and I found .002" out of round on that 
>  crank journal.  Is this the cause?
>  Bob ADler


  Genearlly clearance is  more of an issue with a knock, but one will lead to 
the other, excess clearance if continually run will usually pound the bearing 
out of round, did you mic the big end of the rod too?

  Being that clearance spec should be no more than about what you have in 
"out of roundness on an insert motor (not sure of a poured bearing motor, but 
would assume the same) of .015-.003max, I'd bet the clearance on the "skinny 
side" of the journal is .005 or so, definitely a means to a knock.

  Was the babbit shiny in the rod bearings in opposite sides?  I could look 
for crank specs, but off the top of my head I think .0008 is spec on a used 
crank, .0003-.0005 on a turned crank for SBC's anyway, same or better should 
apply on a long I-6 crank I'd think.

Mike
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