Kipo, were you using a good torque wrench, and if so, at what ftlbs did they break? Did you use moly lube, or something else. Some day I will have to studs and I'm the guy that always breaks bolts off in the wrong place.

Also, how did you extract them?

 

I would also like to know at what ftlbs they broke at cause I have done alot of head studs and I go to 100ftlbs then run it up to temp then tighten them to 130 and have never broke one. Dustin at IIS went to 150 ftlbs cause his kept coming loose and he never broke or had to retorque them. They were the 12mm and not the 14mm.

 

just keep this in mind the arp studs on a powerstroke are 12mm and we crank them to 245ftlbs and dont breakem

 

That is TIGHT! Why 245lbs?

 

cause if we don't they will blow the gaskets out

the thread Pitch is 12 mm the stud dia. at it thickest point is 9/16" but still 125-130 lbs thats not much for a 1/2" stock which i believe is the measurement on the ARP for the cummins

 

I bought the studs from Doug at PDW and he was walking me through it. I took them to about 117-119 lbs. the first time cold and actually broke the threads in the block. Luckily I was able to retrieve it out without too much trouble. Doug sent me another one. I re-tourqued them again cold to about the same but didn't break any. I ran the truck for a few days and actually the ex was the one who broke the gasket. We tore it down again and tourqed to about 112 cold and actually stripped the threads in the cap. Yes I used lots of lube, I even went and bought some more. THAT STUFF IS NOT CHEAP. I even used another torque wrench the second time. When it was cold the torquing sequence just didn't feel right. But after I tore it down while it was hot it went and felt a lot smoother. Doug kept insisting it was a bad batch of ARP's but needless to say when I go to 14mm's it will be with another vendor.

 

But i think the real question is cometic gaskets , phuzion gaskets , o-rings or stockers for 50-60 psi and 500-550 rwhp

 

Go with whats PROVEN. O-rings, ARPs or A1s, and a .020 Cummins "marine" gasket.
3 retorques COLD. That combo will hold 80+psi.

 

I think you need you torque wrenches calibrated. JMHO.
I have read that Craftsman and Husky wrenchs are out 20% right out of the box. I had my SK torque wrench calibrated and it was right on, I try to do this once a year.
1. I do my initial torque to #125, warm up engine to operating temps, let sit overnight with hood open.

2. Next day I break each nut loose one at a time, apply more moly and bring them up to #130, I will then drive it for about a full tank of gas, NOT giving it any BOOST!

3. I will then do another re-torque COLD to #140. Break each nut loose one at a time, apply more moly. Drive that around for about 1000 miles.

4. I will break each nut loose apply more moly, retorque to #140 cold.

This is the directions Enterprise Engines and numerous other members gave me and they have been doing this longer than all of us.

 

I A1 technology's h11 studs in my truck and have had no problem. I did have arp studs and they did not last over 30 lbs of boost. I put 3k miles on and they let loose I used moly coat on the threads and torqued to 120lbs cold brought up to temp and cooled and re-torqued. When head blew checked all of the studs and not two were the same. Put A1's in and torqued them cold to 115 lbs, brought it up to temp and re-torqued them to 140lbs. Then I drove it for a week real easy and then re-torqued hot again to 140lbs still got some movement and not had a bit of problems since.

 

What would worry me is if the wrench you used was in proper calibration or not. The click-type can go off, especially if you dont unload the spring after youre done using it.
Shops can send wrenches out for re-calibration but heck if I know where to send mine. Those sears craftsman ones off the shelf, who knows what theyre actually reading.

 

I am using the Scheid Multi layer unit with their 12mm head studs, so far so good. I've seen over 50 lbs once or twice. Scheid said they are good to 60 or 70 PSI, I cannot honeslty remember.

 

Yes, but Scheid wont gaurantee that gasket because you didnt use the 14mm studs.
I talked to them about 3 months ago about their MLS gasket and they said "I had to use the 14mm studs, if I wanted anykind of gaurantee".
Better talk to them about it.

 

Funny thing about the A1s is ALOT of people think ARP and A1 is the same company. Arp has the same heavy duty studs they are the 265k series.

IMHO, those studs are overkill for you truck. They are designed for pulling/high horsepower trucks boosting in excess of 80psi. A1 and ARPs standard 12mm stud is good for 80 psi of boost.
Either you didnt properly intall the first gasket or you head/block wasnt true. Most HG failures are from improper prep of the block and head. You also need to do 3 retorques. I personally will retorque my studs until I see no more movement it the nut.
Now, I am sure youll get mad at this post, BUT people have been using the standard 12mm studs for a long time and havent had a problem. There are guys who have run 90-100psi on the standard 12mm studs BEFORE the xtra heavy duty studs even came out.

 

I have been into race/high performance cars and trucks for a long time now, a guarantee is a joke. Most parts don't even have one anymore. I really don't want to hog my block out to 14mm, there is not much material left. I know most will say yo have to........but, I'm doing ok and am happy with my results.