ARP Head Studs - Revised Torque Specification
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From: At the beach in little Rhody
ARP Head Studs - Revised Torque Specification
Just spoke to ARP on their LS1 head studs. I have been running them for a couple of years but wanted to talk to ARP about re-torque. They advised me that ARP recently updated their torque recommendation from 70 lb-ft to 80 lb-ft.
Anyone else heard of this?
Anyone else heard of this?
Last edited by vettenuts; Feb 25, 2008 at 12:14 PM.
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St. Jude Donor '08
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I initially tq'd mine to 75 lbs/ft (using their included moly lube). 30lbs/ft on the top row of small nuts.
I rechecked the tq the next day before putting the headers, rockers, etc back on. On both sides, I was able to tighten all the middle row nuts a little more before reaching the same tq setting, but the top row (small nuts) and bottom row held their torque. So, it did settle in a little after initially torquing. I did check the flatness of the heads before installing, and they were flat better than .002", so it was probably the gasket that compressed a little. (Cometic .040" gaskets).
It would be ideal to run the car up to temp a cycle or two and then recheck, but who really wants to go through the hassle of removing the headers, coils, valve covers and rockers again to do so.
Anyways, that was about a year and 5-6000 miles ago. Not a problem or a drop of coolant missing since.
I have no doubt 80 lbs/ft would be a problem. Torquing of nuts is a lot more forgiving than torquing long bolts, since you are removing torsional flex from the equation. You'd really have to go crazy to break a stud, or worry about damaging the block threads with studs, yet both are of concern when torquing the long bolts.
I rechecked the tq the next day before putting the headers, rockers, etc back on. On both sides, I was able to tighten all the middle row nuts a little more before reaching the same tq setting, but the top row (small nuts) and bottom row held their torque. So, it did settle in a little after initially torquing. I did check the flatness of the heads before installing, and they were flat better than .002", so it was probably the gasket that compressed a little. (Cometic .040" gaskets).
It would be ideal to run the car up to temp a cycle or two and then recheck, but who really wants to go through the hassle of removing the headers, coils, valve covers and rockers again to do so.
Anyways, that was about a year and 5-6000 miles ago. Not a problem or a drop of coolant missing since.
I have no doubt 80 lbs/ft would be a problem. Torquing of nuts is a lot more forgiving than torquing long bolts, since you are removing torsional flex from the equation. You'd really have to go crazy to break a stud, or worry about damaging the block threads with studs, yet both are of concern when torquing the long bolts.
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Team Owner
Joined: Mar 1999
Posts: 22,025
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From: At the beach in little Rhody
Good info. I plan to re-torque after my first heat cycle. One advantage of the Yella Terra's or the Crane rockers currently installed is I don't have to touch the valve train. The headers still have to come off though 
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Come to think of it, I'm doing the rocker swap, and a header swap soon.
I wonder if I should bother rechecking the tq on the head nuts, or (since there's not any problems) if simply leaving things undisturbed at this point would be smarter.
I wonder if I should bother rechecking the tq on the head nuts, or (since there's not any problems) if simply leaving things undisturbed at this point would be smarter.
