What does the bolt stretch number thats associated with a rod bolt designate? Is it what the amount the bolt will "stretch" after being torqued the first time? Or after extensive use somehow?

I'm torn down my motor, and I've heard that the bolts on my eagle rods may have stretched.... how sould I meaure this? Would it simply be getting a micromoeter to measure the belngth of the rod and then compare it to what it should be new? Any tech onfo in rod-bolt stretch would be great!

 

 

Only thing I can say is call Eagle.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EF_Chris &raquo;</TD></TR><TR><TD CLASS="quote">Think of a bolt as having a little elasticity. When torqueing rod bolts, using the stretch method yeilds the highest amount of torque. So instead of saying "torque to x ft-lbs", you stretch it to x "s and this produces the desired torque value.
What I do not know is how many times you can stretch the rod bolts before using new ones...which I think is more your question.</TD></TR></TABLE>

 

Whats the torque spec again for ARP 2000 rod bolts on the eagle rods again?

 

on a b18a/b its 28ft/lbs

 

Right, that's it...same for B16A and GSR too....
factory non-vtec spec is 23 ft lbs, and factor Vtec spec is 33....I knew is was in the middle somewhere...thanks 99B16Si.

 

The bolt stretch is measured with a bolt stretch guage, it is much more acurate to torque your bolts this way rather than just using a torque wrench... Carillo actually suggests using this as the only way to torque the rod bolts...

If no one does this, it might explain a bit about why these rods fail ...
The bolt stretch guage is cheap $100-$150 or so, a excellent investment when rebuilding the engine.

Cheers

EDIT: Sorry didn't read your post properly. You cannot measure bolt stretch after they have been used, since you did not know how much they were before they were used. They are not expensive, so rather replace them than be sorry about it later.