special tool

I would like to point out that the mls on my car has been torqued/installed 3 times.
It is 100% fine and I plan on keeping for the dyno and drag races coming up.

tyro

I'll assume you're joking..you've mentioned several times that the wide fire ring gasket is the way to go..

KuHL 951

I talked to ARP Special Products Division today just to find out a few things. He said they build the 'specials' for engine builders such as EBS and others and they are not in the catalog. We talked about a few people here having leakage issues with the 65# final pull. I got the feeling that it wasn't ARP's value and more representative of the particular builder. He went through the specs on the hi-strength alloy with me. For the 12mm stud 'as designed' he said a safe pull was 85-86 ft-lbs. He said at 95ft-lb the stud will start to stretch and can yield detrimentally at 100+. To me it verifies that picking 80 ft-lb for mine will be fine, especially after headwork. I just thought I would toss that in there. It may very well be that 65 ft-lb just isn't enough unless the block and head have both been milled correctly for a rebuild. I can imagine that the independent builders do the machining as standard procedure for anything they are having to guaranty themselves.

billindenver

65 was not enough for mine with the head and block freshly milled. At least not with a stock type HG.

special tool

That was a while ago.
I have good luck with the newer mls with the fancy glue coating on them.

tyro

65 wasn't enough for me either. What value did you go with, Bill?

Is your car up and running again - and not losing coolant?

billindenver

I went with 85. So far so good, but I have not checked retorque yet, nor has it been on the track.

KuHL 951

Did you end up using the initial settings that came from EBS and just up the last pull? Did you relax them 180 deg. after the first torquing. Glad to hear it's holding so far.

tyro

With the ARP studs, one end is fine pitch versus the stock studs that have identical thread pitch on each end (12x1.5).

In thinking of bolt design, how are thread pitch and applied torque related?

Given a coarse thread stud such as the stock head studs, would a fine pitch stud of the same material require more or less applied torque to achieve the same clamping force assuming identical thread lubrication? How much is the difference? Minimal?

Since the studs are made for EBS by ARP, who came up with the torque value? ARP?

In short, is 65ft-lb of torque applied to the stock studs the same as 65 ft-lb of torque applied to the ARP studs?

Either way, I'm going with 85.

billindenver

I just increased the last pull, then let it sit overnight...and backed off 180 and retorqued. It then set several days while I waited for new exhaust studs to arrive and I retorqued again.

toddk911

After having my HG done recently with now Cometic MLS and ARP, I have had no issues.

Also, the guy that did mine did not go by ft/lbs but by distance and/or number of threads exposed to know how much to tq. it down.

TRP951

the only thing about that is you have to make sure to install all them the same height or it will differ from stud to stud

KuHL 951

ARP has you set the studs with a fixed deck height anyway and wants the Loctite set before torquing. It sounds like counting threads would be a bit subjective but I see what he is going for but in a real complicated way. 80 to 85 ft-lb and be done with it; recheck if you have leakage or have the camtower off for some reason.

I'm more concerned about my machine shop getting the old studs out.

Tom M'Guinn

Hmmm... sure he didn't use the "torque angle" method, in which the torque is set by measuring the amount the nut is turned? I can't imagine getting a proper/consistent torque by counting threads.

Tom M'Guinn

Pure speculation, but wonder if it was to keep the studs from turning while a machine torqued the nuts.