ARP Head bolt install help needed.

[Goat Blower]

ARP is very specific with their torque specs using moly lube or oil. Where's their torque spec for using Loctite? ARP's are designed to have a certain amount of stretch to hold properly, I'd be interested to know exactly how different that would be using Loctite.

[Shane@DBPerformance]

You put Loctite on the threads in the block, not on the threads sticking out. You put the lube only on washers, nuts and threads on the head side. On some cars that have the head bolt holes going into the water jacket, you need to use something like Loctite or RTV on that side of the stud to seal it.

[Raptor]

I will throw my opinion in here, take it for what you want. I don't lock tite them in and have never had one back out. We are talking specifically about the 4G63 here so the water jacket sealing doesn't matter for this app. I turn them in all the way in after making very sure the hole is clean. I tighten them in the hole as well. There is no reason not to do this, the stud will not crack the block and to maintain the torque spec, the stud should be very secure in the block. The use of locktite at that point is not necessary, it probably won't hurt anything however it will make the studs more difficult to get out and there will be residue in the hole for the next time. The use of moly lube on the threads and nut bottoms was mentioned and should always be done. This BTW is the way most every performance based machine shop I know installs head studs some with over 50 years experience.

As for the torque spec and sequence, if you torque the heads on tighter than necessary with a motor that hasn't been torque plated for that spec, you are making your cylinders more out of round at the top where it matters most. Don't over torque them. We go 100 but only on motors that are done with a torque plate at that spec. Otherwise, the rest get torqued based on what they are 6 bolt, 7 bolt, gasket type etc. As shane mentioned, with certain gaskets, retorque may not be required. I always do at 100 miles, but it isn't always necessary. Depends on the case at hand.

Also I know there are enough "let er buck" type mechanics on here that will say that torque plates are not a big deal and you can torque your studs to rediculous specs and honestly you will probably get away with it. But are you making the power consistantly that you would be if your cylinders were still actually round all other factors equal?

[Shane@DBPerformance]

ARP makes the undercut versions of their studs also, which are meant to pull down on the head once torqued down and are less likely to need re-torqueing.

[Onefast99gsx]

This turned into quite a topic. I put the head on NOT using locktite. I did a 45-60-75 as recommened by JET(Thanks). I will retorque after a hundred miles or so. I think if ARP wanted you to use locktite they would tell you. I don't necessarily think it's a bad thing to use it, I just don't prefer to do it. I would imagine that if you were to ever take the head off again, you would have to run a tap thru the stud holes to clean the locktite crap out otherwise you could get false torque readings?

PS- I also sprayed 2 coats of copper spray on my new OEM stock headgasket and then put the head on.

[Raptor]

The other thing to pay attention to as far as over torque goes. The torque specs given by ARP are based on 75% of the yield strength of the fastner. At 110lbs, you are pretty much at the point of stretching a 12mm stud.

[Onefast99gsx]

Guys- why is it that they want you to only finger tight them? I moly'd the heck out of everything, threads, washers, nuts, my hands in the process. When i was torque'n them down it was hard to tell if the stud was going in any further than my finger tight was.

[Alpine TSi]

Hopefully you didn't do what I did and used moly lube on where the stud goes into the block. I found out that wasn't so good, luckily it was caught before my head lifted off the block.

[TheBlizzard]

When I just did mine Nash and I just finger tightened them into the block and then tightened them with a allan wrench until the were firmly seated into the block but not really tight either. Then used molly lube on the nuts and torque to spec and then retorqued after a week of driving. I don't see lock-tite as a bad idea but I don't you have to do it other wise ARP would suggest it I would think.

CRAIG

[Onefast99gsx]

I used moly lube on both ends of the studs. The little pamplet that came with the ARP said to lube all threads, washers and nuts. Huh??????