Studs discussion

[RescueF250]

Seems like theres a few variations that everyone is doing across the board using ARP studs. Seem some torque n loosen using Ford directions. Others Arp directions. Also various end of torque numbers of 275, 300, 325, 345. What's the actually failure rate at what point has anyone broken a stud ?

I know we had a dicussion in the 6.0 about this and everyone did their own way. Read thru a few different threads here all being different from one person to the other or shop to shop. So the purpose of this maybe clarify for anyone that is looking into it. Maybe can be made into a sticky for folks to refer to when they do their studs.

List your choice of final torque how you reached it ? Your setup on your truck ? Boost pressures etc. Did you do it one at a time or completely remove the head and follow normal procedures or did you go about a different way to final torque.

 

[08BIGRIG]

When you open the box of studs, use whatever lube and torque spec that they tell you to inside the box on the instructions. There is two different kinds of lube and that is why I say to always use whatever comes with the studs and follow the toque sequence that ARP says.

 

[Dzchey21]

the stud failing really isnt the issue its cracking the block. When i talked to Josh at rcd he said they are only doing 250 ft lbs with the new arp lube to ensure this doesnt happen. He had stated that the clamping force at that torque was equal to top fuel clamping forces... i dk, i know mine are probably way too tight at 325 ft lbs and i would never recomend that to anyone on a street truck or really anyone LOL

 

[Powerstroked162]

Yours was puking at 250-275 wasn't it? 18 some years ago lol

 

[Dzchey21]

mine puked at 190 on elites studs and lube, which supposedly is slicker than the arp lube, but i know after about 70 psi of boost is when i had issues (850 hp) so i went big on the torque, kinda wish i would have just done 250 and see if that held. but I know my block is cracked, i have sealant on the studs now and so far so good (almost 2 years like that) but like i said im not going to really recomend that to anyone.

 

[Powerstroked162]

No I understand. I remembered you having issues and I couldn't recall what it was exactly or why. A lot has changed with studs since then too.

 

[Dzchey21]

yeah for sure, this was when the new arp lube came out about the same time, and the studs had already been in my truck for about 2 years, plenty of nitrous passes ect over 800 hp, but for whatever reason when the boost and back pressure came up so did the cylinder pressure.

 

[webb06]

I torqued mine per the arp instructions. 275.....final torque

 

[Highroller54]

Has there been any trouble cracking/blowing gaskets at 250?

 

[powerstroked08]

I did one at a time. I torqued to 90# and then loostened 3 times then I went to 180# and then went to the next stud. Once I did all of the studs I did my final torque at 275# as per the ARP instructions. So far so good(1 year and about 20k miles).

 

[HOOV3R]

I prefer not allowing the stud to bottom out in the block. I feel the force of the stud bottoming out in the block may be causing some of the cracking issues at higher torque values.

 

[sledfreak]

Did you guys try putting 3/16 garloc gasket material in the bottom of the hole, so it won't bottom out,the trick works good on big valve bonnets,in high torque applications.

 

[Powerstroked162]

Did you guys try putting 3/16 garloc gasket material in the bottom of the hole, so it won't bottom out,the trick works good on big valve bonnets,in high torque applications.

Liquid/paste or actual physical fiber gasket?

 

[sledfreak]

fiber

 

[JrStroker]

Swamps diesel put my studs in. Did not remove the heads. Just dropped them in one at a time. That was 7 months ago I think. So far so good.

 

[Fordtrucks]

I did mine one at a time. It failed. Wont do that again.

 

[drunk on diesel]

Did you guys try putting 3/16 garloc gasket material in the bottom of the hole, so it won't bottom out,the trick works good on big valve bonnets,in high torque applications.

good idea

you definitely don't want to bottom out a head stud... run it in and back it off a little

as far as the different torque values with different lube, the goal is the same... a certain amount of stretch on the fastener = a certain amount of clamping force. With a lube with a lower coefficient of friction, it will require less rotational torque to yield the same amount of stretch on the fastener

 

[Crack85]

good idea



you definitely don't want to bottom out a head stud... run it in and back it off a little



as far as the different torque values with different lube, the goal is the same... a certain amount of stretch on the fastener = a certain amount of clamping force. With a lube with a lower coefficient of friction, it will require less rotational torque to yield the same amount of stretch on the fastener

Interesting, elite's stud instructions say to bottom the stud out finger tight.

 

[powerstroked08]

Also even though a stud might only require 180# for a final torque doesn't mean that it won't crack a block. Those studs streach less so it adds more clamping force with less input torque but has just as much if not more "pull" on the block.

 

[drunk on diesel]

Interesting, elite's stud instructions say to bottom the stud out finger tight.

I would say finger tight and then back off slightly. Bottoming out with the stud not having any tension on it is fine, but the problem is (especially with a higher friction lube) is that you often put tension on the stud against the block when tightening the fastener

When you tension the stud against the bottom of the hole, you compound that tension with the final torque applied to the fastener.