arp head stud over torque

[Daytonadrew101]

Well while chasing an exhaust leak, i figured to check the torque of the arp head studs. I went off the knowledge center of turbo-mopar which said to torque them to 80ft/lbs. I checked them to that torque. Now i know when you over torque anything, you back out and cycle to check for damage. I am running a cometic head gasket at 20#, i wanted to check if i loosen and retorque to 65ft/lbs is the gasket already crushed beyond hope or should i just leave the torque. I have seen many people talk about torqueing thier stude to 80 and even 85ft/lbs.

In my belief, i think i am going to have to run the motor as is, i think maybe the cometic mls gasket is too far crushed to retorque at a lower value.

This maybe not such a big thing since i will have to remove the exhaust manifold i think to fix a leak

[Daytonadrew101]

torqued to 80ft/lbs with molylube

[Lotashelbys]

A Cometic gasket is multi-layer steel so it really does not "crush" like a standard composite gasket. I would think if your head and block were both machined flat before the gasket was installed and you had to de-torque and re-torque the studs you will be fine. I have gone as far as 85-90 ft/lbs before on the ARPs. A leak-down test will tell you if there is any issues after you re-torque as for possible leaks.

[Daytonadrew101]

I did have the head and block machined with the correct RA. I thought I maybe fine with just leaving the studs torqued that much, from a few on this site torqueing them down to 80+ft/lbs . ill do a leak down check. I just need to get my compressor back. thanks much, just needed the backup


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[turbovanman]

I go 95 ft/lbs.

YOU MUST make sure the studs don't bottom out in the block, if you used the Honda studs, you MUST tighten them down then back off a few turns, then when installing the nuts, HOLD the stud from moving otherwise it turns back in and will bottom out and you won't get the proper torque and you can crack the block.

[ntxdodge]

I torque studs to 85 ft lbs.

I was surprised to read in the 1993 Chrysler Service Manual page 9-32 for 16 valve head with headbolts to:
1st torque all to 45 ft lbs
2nd all to 65 ft lbs
3rd all ( again ) to 65 ft lbs
4th + quarter turn. Do not use torque wrench.
“Bolt torque after ¼ turn should be over 90ft lbs. If not replace head bolt.”

I was somewhat stunned to see the Chrysler Service Manual say the torque of the head bolt need to be over 90 ft lbs. after the ¼ or 90 degree turn. So for this reason I torque to 85 Ft lbs since the studs are stiffer than head bolts. But you could also say the studs torque should be at least 90 ft lbs also.

Ron

[Daytonadrew101]

Thanks for the info guys, everything turned out ok. I just kept them torqued to 80ft/lbs. compression check was good and the car runs fine. The studs were placed in finger tight then backed out a turn.

[mopar2ya]

ARP calls for 65 with moly lube. Ive never gone over 65-70 lbs and never had a failure or blown HG.

[Lotashelbys]

Quote:

Originally Posted by mopar2ya ARP calls for 65 with moly lube. Ive never gone over 65-70 lbs and never had a failure or blown HG.

You have to get with the times dude! lol With the new ARP Ultra-Torque lube they raised the torque on most of their fasteners.

[turbovanman]

Plus they instructions don't really list a torque spec per say, its generalized and you have to figure it out based on faster diameter, needs etc.

[Daytonadrew101]

gotcha. i ended up removing the fasteners and checking them for stretch and checked the head/block and gasket. Everything was well ok. i torqued them to 70ft/lbs moly.

[tryingbe]

http://arpinstructions.com/instructions/241-4501.pdf

90 lb ft with ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT

[ntxdodge]

Finally someone with a ARP data sheet with some real information: 90ft LBS which correlates to the Chrysler manual I listed above.

Ron