it goes way back. it was a major problem with DE's and effected all the early builds. Guys were chasing all kinds of non-existent issues like boiling coolant etc trying to figure out why it was happening. Some were even going so far as replacing the coolant plugs in the head with giant allen bolts and torquing them down to create pressure on the headgaskets between the cylinders (LOL). Eventually everyone went to 1/2" headstuds, boom, problem solved. Until the L19s came out which allowed getting real torque on the head studs without drilling and tapping the block.
I forget, what is the torque spec on the standard ARP? 65-75lb ft? Thats not going to cut it. At least, it didnt on my 350z. Made it about 5-6 blocks from the dyno. Then I swapped the block for one that was drilled and tapped for 1/2" studs, and now we are about 10 years since that engine went in the car and its still doing great! So, I like to get about 90-95ft lb on the headstuds (with moly lube).
Last edited by phunk; 08-09-2014 at 02:59 PM.
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