Installed my new motor, 4 miles later, head gasket leaking!!! Found out that the head studs were only torqued to 95 foot# like ARP said. Called PRD and they torqued their studs to 130 foot#. Why does ARP suggest to torque them so low??? Just following ARP's instructions..Not happy one bit!!

 

ARP recommend that TQ using their super-slick lube. With regular motor oil, you should go higher.
I believe Don M has tested the ARP to 120+ with good results....

jh

 

When I installed the new o-ringed head and studs I torqued it to 96 ft/lbs with the moly lube. I have seen 70 psi a few times and 65 a bunch of times. No problems at all. I recently changed it to 110, but I had no problems at the lighter setting.

 

PDR told me 125-30 with motor oil
As Hohn mentioned the 95 was with their lube but I never used it so.....?
Did you use their lube?

 

PDR knows what they are doing, ARP don't know squat!!!! Ratsun, your little guy burning rubber is the best!!!

 

Yeah hes cool. I first seen it a couple of years ago on the TDR but couldnt get it to burn out after I shrunk it down (75x75), good thing member satburn came along and shrunk it down so it would still burn out (I'm a dummy with this puter stuff ). I have seen many real cool ones but they were pretty large 120x120 or so. One was a pick-up with stacks blowing smoke

 

Uhhhhhh doesn't ARP make the studs? I bet if you broke one off in the block and you told them you torqued them to 125 they wouldn't do squat for ya.

I know you can go over 96 ft/lbs but sayin PDR knows more about the tensile strength than ARP just doesn't make sense to me.

Dodge Diesel did you warm the motor up and then retorque them? Just checking. Hope you get it figured out.

 

You bet ya. Warmed it up, drove it nice for 2 miles, drove it normal for 2 miles, parked it back in the shop and a puddled appeared under the truck.. Head gasket leaking out, thank god, not into the new motor, what a . Remove head, replace gasket, re-torque to 130 foot pounds, all good now. Makes me really unconfident about this stud kit and will this happen again. Kind of makes me want to sell and go newer but my 2001 is such a good ride and I just spent a small fortune!!!

 

mine are at 120...no problems

 

i have my ARP instrucs right here and it says to go to 96pds with THEIR supplied lube, 122pds with regular motor oil.

 

Torque is all based on friction coefficients. ARP may be using some sort of super slick-em like Jet-Lube while PDR might be basing their values based on light machine oil or a dry bolt. The best thing to do is make sure your bolt is clean, the hole threads are clean and then get with ARP to find out what lubricant they are using for their torque values.

 

Sorry about your luck bud. Mine are at 96 w/ the lube and no problems. Hoipe you keep her together this time.

P.s. How come you had to build a new motor?

 

ARP DOES know what they're doing... they're pretty much the top dog when it comes to fasteners... and yes, PDR knows what they're doing too

 

Are you 100% confident the block and head surfaces are flat?
If your first run was a gentle one with low boost #s and you dont have a crazy amount of timing then I would be suspicious as to why the gasket let loose even though you were only down to 96psi. Did the gasket show evidence of the combustion leak? I got the wrong one on my 24v that leaked out AF from one of the water jackets and after taking it apart and having a real close look it was clear that it didnt quite cover the water jacket. It was one of those cases where this part # superceded that part# and so on I would rest assure the stud kit will do its job. FWIW I dont like torquing the studs with oil as both my sets galled a little durring the retorques. I'm going to try the ARP lube next time?

 

Yes. The block was decked and the head was totally rebuilt and plained. The only used part are my injectors. Does anyone think the head gasket will let go again after I have had the studs torqued to 130 foot pounds?? The leak thing makes me want to stay away from twins but I need to run them to cool the EGT's down....