ARP stretch guage options?
 

The spec for the ARP rod bolt that I have is .0120, will any stretch gauge work?

There are a couple of options available, but they only read to .001 and the ARP gauge reads to .0005.

I just used a typical micrometer, and measured the stretch at different torque values I made sure to measure the bolt at the same place each time.

I got very consistent results with the ARP bolt stretch. all 12 bolts fell into the proper stretch range .012 inches (.303mm) at 45 ft lbs to 50 ft lbs. This fit well with my memory of what Henry Schmidt said it takes to get the proper stretch on ARP bolts.

(Note this was for my 3.2L with 9mm rod bolts. I'm betting the 10mm bolts would take more torque.)

because I was using a typical socket and torque wrench, plus a standard micrometer, I increased the torque by 5 ft lb increments then measured the resulting stretch. 5 ft lbs at a time ensured I was actually moving the nut and not just measuring static torque.

Richard

Any fixture will work, even the one from Moroso.... :) It is the indicator that is important. The ARP one is a nice unit, I have one. I used to send it around to fellow Pelican Members until it got lost in shipping.....

I did not need the torque stated above to get the stretch but did need around 40ish lbs to get it. Based on that I have used the stretch gauge on every ARP rod bolt since. I just don't trust the torque method for ARP rod bolts...

If you buy the ARP unit you can sell it for 75% of what you paid pretty easily.

Cheers

Thanks.