arp studs retorque?

[lb7lbz]

have some arps coming for my truck w the head gasket kit. i have heard arp recomends retorqing these things after 500 miles or something. i really cant imagine ripping everything back off again to get at the studs. so for you guys who have these in your truck what did u do?????

[More Power]

If this is an LB7.... I'd be inclined to torque the head stud nuts twice over a 24 hour period (fully torque the stud nuts, let it sit overhight, then torque them again 24 hours later). Gaskets will compress a little during the first few hours. Checking/retorquing the next day should take care of any relaxation in torque. Don't loosen the stud nuts when doing this, just check the torque values - add more if necessary. Or.... you can take another afternoon to retorque them after accumulating some miles.... I doubt I'd do it on a daily driver...

This is one reason why the engine manufacturers went to TTY (Torque to Yield) head bolts. The final torque angle applied to the bolts during installation takes the bolt shanks into an elastic zone, which allows the bolt to retain some spring in their clamping force, and which helps provide the required clamping load over time and thermal cycles.

Jim

[lb7lbz]

thanx for the reply yes this is on an lb7, and yes it is a daily driver w a built trans and will be getting a efi tune after this head gasket job is done. just seems likie a lot of work to take it back apart thats all. just got my gaskets and head studs in today, start reasembly nxt week.

[Kennedy]

Did you triple torque them?

[lb7lbz]

yes j/k if you are refering to the 3 step torque process i did that then let it sit 24 hours and rechecked em all. thanks for the reminder

[Kennedy]

Actually, you run the 3 step process 3 times as indicated in the destruction sheet. The idea is to stress and then relax the stud.

Rechecking after sitting won't get much of anything. You want to make the steps in TQ fairly sizeable as if the steps are too close you'll click off the wrench before moving the nut. You'd find much more consistency by backing off and then bringing up to TQ.

[lb7lbz]

what i did was torque all studs to 60 pounds then to 90 then 110 then finally to 125 let sit 24 hours then retorqed. some did move some more after sitting.

[Kennedy]

They'll probably be fine, but I think you'll see what I am talking about if you read the note paper in the box.

[lb7lbz]

actually idid read the sheet in the arp box. maybe i misread it but i thought it said to do the torque in 3 increments,anyway putting the other head back on tom so i will try it the way you suggeseted and if i have any problems down the road with the side i did my way i will know why,lol. thanks for the help. j/k i actually want to talk to you about efi as soon as this truck is up and running with a few miles on it.

[Kennedy]

Verbatim:
7. Following the manufacturers recommended torque sequence, cycle teh head studs three times (tighten then loosen) to teh torque specification of 125 ft lbs with ARP MOLY ASSEMBLY LUBRICANT before tightening the studs a fourth and final time to 125 ft lbs.

We actually use a special EP lube/grease that is even better than the ARP stuff. I don't know where my machinist gets it or what it is, but it's very good stuff.