All bolts stretch,
It's the amount of the stretch that is the point.
I have used ARP bolts exclusively since I had a bad experience with "used"
rod bolts.
I reused a set of rod bolts on a GM 396 rebuild years ago, we hopped up the
motor with some go-fast adders like intake, racing heads and the like. I am
very meticulous about torque settings when building an engine, on this one
we "staged" the torque settings just as the manual said. The engine ran fine
once started, we "ran-in" the cam for 30 minutes at 2,000 rpm just like we
should, the engine got up to temp and we backed it out of the garage for a
trip down the street to see what we had made. I put the car in drive and as
soon as the engine speed went from about 1,100 to 2,000 a rod bolt let go.
Needless to say my buddies and I were upset, we thought it was something we
had done but once we tore the engine down we found the problem. I took the
suspect rod, piston and cap to Laughlin Racing
(http://www.laughlinracing.com/) which is near my home and they confirmed
the problem.
A $2.00 bolt and nut ATE $1,100.00 worth of machine shop work and parts.
So as the old adage goes, you can pay now or pay much more later!
-----Original Message-----
From: spitfires-owner@autox.team.net
[mailto:spitfires-owner@autox.team.net]On Behalf Of Larry Vaughan
Sent: Thursday, January 09, 2003 7:27 PM
To: spitfires@autox.team.net
Subject: Re: new motor
I bought all the parts for my motor rebuild from BPNW. I asked them about
new rod bolts. They said the original rod bolts were reusable, unless they
were stretched, and if I didn't need them I could return them. The machine
shop said they used the old rod bolts because the new ones stretched??? I
called BPNW and they said, we received a bad batch of rod bolts, but thought
we had culled out the untempered little culprits. You must have got some we
missed. We will have them picked up, by UPS, and refund your money.
Larry
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