Torquing Arp 625's.

[schaef_12]

I'm looking for a good torque procedure to use with my firerings and 625's. The firerings are cut for regular 12mm studs. My plan was to just use the Cummins torque sequence and run in 10lb increments. I'm not sure what torque value's to use though, as far as a final torque value and how many retorques I should do?
Thanks
Corey

 

[PRattenbury]

I spoke to ARP directly, and I recommend you do it as well. The torque pattern is the same as Cummins specifies. I used 3 10 ft/lb increments on the way up to 160 ft lbs. The difference I got from ARP was all three torques take place at initial assembly, and was referred to as 'cycling the studs'. This is different from the initial torque at assembly, retorque after so many heat cycles, and a last retorque at 500 miles or so. But definitely check with ARP, they'll give you the exact scoop. It's been a whille for me.

 

[RedPuller]

I would be curious to have some experienced advice on this as well. I did the three initial "cycling" torques in the factory sequence as stated in the instructions before any heat cycles. Did the first re-torque after the first heat cycle and now am wondering how many more re-torques to do being these studs are different/stronger material than the original studs. Since these studs don't stretch as much as the originals, I heard we can treat them like 14mm studs and only do the one re-torque after the first heat cycle but I am not sure how true that statement is.

Joe

 

[03kbcobra]

Instructions are provided with studs for torques. Three full torques. loosening between torques. The head is what requires a sequence, so it will not change from one set to another. You maay consider snug on first pass, 50%-75% second pass, then 100% third pass. Then loosen and retorque per instructions. I think it would be prudent to check after a few thousand miles when cold to make sure all are still at final full torque spec.