Thread: The Great Headstud Thread

I just ordered some ARP's i think they will be fine(i hope) now I have to take the head off.

ARP head studs ARE NOT designed correctly to the block. They are undercut which means they are made to stretch to get to the correct TQ clamping value. If your motor gets too hot, the ARP studs will relax and you will loose all your TQ clamp load. This happens easier if they are over Torqued. Also, the threaded part that goes into the block does not grab enough threads and actually warps the cylinders slightly at the mid point. I have actually measured this VS greddy studs. The ARP studs also grab the top thread in the block if they are tightened into the block before installing the head. This locks the stud against the top thread and will make the threads lock together when you TQ the studs down. This can make them nearly impossible to remove from the block sometimes and or will cause damage to the threads.

I have 2 sets of Greddy studs in my possesion and these are the nicest I have seen for an SR20 motor. The cosworth studs I have not seen personally, but I'm sure they are as good if not better.

I have known that the B series G.E. studs work in SR blocks for some time, but they are still not made perfectly for our motors. but yes, they do work.

well if the guy can come up with the aebs ones then those are what ill be using, if not then possibly the golden eagles or the cosworth, The cosworth ones im sure are very good, the greddy and tomei are just way overpriced

Fug it, I'm done. No information from me thanks to Autech

I got my greddy studs for $313 shipped..... that might have been a onetime only though.....best studs I have seen for the sr, and I have had the old and new ARP's. They are no good.....Supposedly different material. Did not seem like it, but the torque spec jumped from 75ft-lbs all the way to 105ft-lbs, yikes on our aluminum blocks....

Heres my 2bobs worth (20cents worth).

ARP studs are fine. Ive seen them used over, and over and ill repater over here on big boost with no issues.

That **** about the centre of your bores warping is bull****, provide everyone here with detailed pics and spec on how it did this. Keep in mind, block strength on the SR through that part of the block is over 1200psi per square inch with the alloy they use.

For those who have "stuffed threads" its because of these reasons:

• you didnt properly grease the studs up
• you didnt retroque after 15,000miles
• you didnt install them with the correct procedure and just cranked the torque up on them stupidly high initially(which is a false figure when you do this)
  

The reason you all love the studs that bottom out is because it requires little effort and little brain work. They bottom out, and you cant torque them any further, and stretch them in. Once their done, their set - which from an engineering perspective is totally the worst way you can do it. Steel stretches and tempers through heat, which is why ARP design their studs to not bottom out. If you torque a bolt up, and its bottomed out, but still torqued right up then this same bolt heats up past 100 degrees celcius through heat saturation it has no where to expand so you end up with miniscule stressed segments of steel that over time can weaken and stretch excessively or snap or crack.

^^^^ as far as what we have heard ARP has already admitted to the stud being a false design. There has been several cases where this has been talked about where people have called them on their design. They essentially said they were gonna come out with a new design that will bottom out. Why do you think every i mean every other sr stud out there bottoms. Because thats the way it should be. They dont make this design for no reason.

You can plainly see that for one which to me is the biggest concern is that the arp does not use all the threads in the block which in turn lessens the strength or hold ability of the stud. It appears to use almost half the threads which is a bunch o BS. Every other compay uses a stud that has almost twice the threads as the ARP and bottoms out the block. When you torque the nuts on the head it pulls the stud upwards locking against the threads. Noone has ever had any problems with using any other studs but several people have had multiple issues with the arp's even to the point where they ruined the threads in the block.


Again ARP has already admitted fault with thier design because of distinct evidence showing so. Cant argue with evidence. ARP's answer to their problem too was not to use 75 ft-lbs and go all the way to something like 95 ft-lbs. Which still didnt solve the problem. Its a problem with the design and again i refuse to use them and pitty anyone else that would continue to use them after all the problems. Sure there are success stories but more horror. Why get those when you can get a set of the Golden Eagles for the same price. Or AEBS for a tad more.

Please take the debate of ARP vs. all other studs to this thread where it belongs: http://www.sr20-forum.com/turbo/4708-headstud-comparison.html

This current thread should be for group knowledge I think. The debates can be had elsewhere, and then the results posted here instead. That's how I viewed this thread anyway. Otherwise, it's just a duplicate of the thread I linked to above.

true but it doesnt bother me, its all good knowledge but yeah as long as it doesnt get out of hand. Then i would say take it elsewhere. But everyones opinion is welcome and if that requires an argument back then so be it. But again dont really need to get into a pissing fight over it. Its more about the info and whats avaialable, prices, and some comparison or actual experience with them is more what we are looking for.

It just seems best to take up the argument where it left off, as everything we're going to cover here will probably have been covered there. If, after reading all 11 pages in that thread, Autech still has something to say, he should point it out there. I'll gladly join him.