anyone know (looks at eric )., or know where i can find the tightening torque amount and sequence for ARP headstuds (for VG30DETT obviously ).. looked but cant find anywhere and i wanna get the heads back on tomorrow, i know to finger tight the studs in etc but dont know the tightening specs/sequence for the nuts.. can anyone help thanks in advance guys scott
if i remember they are torqued to 50ft.lbs in same as stock sequence backed off.. re torqued backed of and re-torqued in 10 ft.lbs increments upto 90 ft.lbs let them sit then recheck torque at 90 ft.lbs does this seem about right????????
From Z1 Web Site; Procedure for Installing Head Studs: Finger tighten all the studs into the block once to make sure they fully seat. Make sure to put the 2 shorties in the correct places. Remove each and apply red loctite to the threaded ends going into the block and screw them back into place fully seated again. Install the heads. Install washers on all studs. Apply the ARP moly lube to each nut on the threads and bottom contact surface. The ARP lube is critcal because it sets the correct torque for the studs. Use of other lubricants will require other unknown torque values. Torque each to 90 ft-lbs in the pattern and manner noted in the factory service manual 3 times.
Putting red loctite is asking for big trouble later down the road. For those of us who build race engines for a living, the correct way of doing this is to oil the bottoms of the threads that go in the block. Thread the studs all the way down to the bottom then back off the bottom by one half a turn just so that the end of the stud barely seats itself at the bottom of the threads. This is very important to do. Next step is to install each head as procedure. ENSURE you use both the stock locating washers as well as the ARP washers included in the kit. The ARP washers are not thick enough to ensure that the ARP nuts don't bottom out on the threads. This is the reason for using the stock locating washers in conjunction with the ARP washers. Now onto tq'ing. DO NOT use the ARP moly lube when tq'ing down the heads. That lube is only rated for 75ftlbs with that dimension ARP stud. ARP even tells you that if you proceed to tq beyond their suggest rating of that stud that you MUST use oil as it gives the correct tq/clamping load. So ensure you install both washers then apply engine oil to the threads of the stud, on top of the ARP washers and to the threads of the ARP nut. Ensure before you to and wind down the ARP nuts that you double check to ensure that some of the oil has gotten between the ARP washer and the stock locating washer. This is important on friction and tq'ing effectiveness. Proceed to snug down each ARP nut in the same fashion the FSM suggests per the tq'ing sequence. I personally go straight to 50ftlbs of tq on all the studs and double checking the tq on each stud once I've done them all as some will loosen as the head begins to seat itself. So always go over the tq sequence a few times to ensure they are all tq'd down correctly. Once you've done that proceed straight to 90-95ftlbs. I personally go to 95lbs. Repeat sequence to check tq figures and you are done. Hope that helps. This is the correct way of installing ARP headstuds.
you put the stud in a bind at the bottom. When you tq the nuts down and are beginning the sequence if you don't have that little extra gap you will most definitely need, you will end up putting the stud into a tq bind enabling it to put excessive stress on the bolt hole etc etc. When you put loctite in the mix with it it doesn't allow for the stud to expand and contract. It actually fills the void in between the threads and can/will cause issues with that much clamp load being exerted. With oil, you allow the threads to still have engagement and it lubricates the threads to ensure no other form of binding occurs.
Ok, I can understand that. But how do you ensure that the last half a turn does not get done up again as soon as you start doing up the nuts on top of the studs? Won't the studs just turn and bottom out again?
Thats the point of backing the studs off the bottom of the hole. To ensure that you aren't tqing at the bottom and causing damage to the stud, you tq as the stud is still on its way down not on the stud where it has no room to go. When you do tq you will use up that void but you are tq'ing to an effectiveness that doesn't put the stud into a bind where you could twist the stud and cause damage to it. The point in backing the studs is done for the very reason you stated above.
hahaha I just spent half hour looking for this thread.. wish I remembered I commented on it earlier! and yes I did need it
What about after a engine has been started/fired up. Is there a possible need to do a re-torque of the ARP Head-studs once again? I read this somewhere.Is it helpful?
small stud location i found this because i didn't see it in the thread and it was what i was looking for. http://arpinstructions.com/instructions/202-4308.pdf
