Originally Posted by Cab_Burge
When I first started using ARP rod bolts in stock 440 rods the instruction said to torque, torque them to the torque spec three times with the lube and untighten them three times BEFORE using a stretch gauge work
All the ARP rod bolt instructions sheets I have show different stretch lengths for the 7/16 rod bolts depending on the under head bolt lengths work scope
No matter what not all bolts, even made by ARP, are exactly the same and equal on torque needed to stretch them exactly the same twocents up


This is fact. iagree

I just got done proving it to my self. Original Molnar ARP2000 bolts that came with the rods go to 85'lbs to get 0062 torque. I ended up having to order two new rod bolts because using the torque angle method I over stretched the fist two I did... (long story) So after I screwed up the bolts, I knew I wasn't going with T/A.....So I ended up going with finding the torque that equaled the stretch tolerance (0060 - 0064) The guy I talked to at Molnar Monday said I was doing it right by doing it this way.

With this being said the new bolts I got in only take 82'lbs to get the bolt to stretch to 0062. If I use the 85'lbs the stretch goes to 0065+ I can only attribute this to the possibility of these new bolts coming out of a different "run".

So what has been working for me is sneaking up on the proper stretch by torquing the bolt incremental until you get with in the published tolerance.
Call the bolt manufacture or rod manufacture who ever the bolts come from and get their opinion. Molnar has been super helpful, spent 20 min on the phone with me talking about bolt tech.

Molnar said you won't over cycle the bolt by doing this. We can tighten and loosen the bolts as much as we need to. It's the pull force when running that stress the bolts.

That's why I'm logging my over all length's of the bolts so I have a base line to go by.

This is my 2 cents twocents.... not sure it's worth it or not. shruggy

Last edited by KD800X; 04/10/20 06:44 PM.