judge88

im getting ready to put my head back on after blowing the head gasket and getting the head shaved. it already had arp studs in it. whats the proper way to tourque or retourque the studs since they have already been installed? do i need to start over as if they were new? im gonna put them in like the factory service manual says but do i need to retourque then after a couple heat cycles again or just do it again in like 6 months or a year? thanks justin

CTDHokie

Nice truck, how much power was it putting down before it blew the gasket? You got to get that thing back installed and come up to Kauffman's dyno for the Spring Fling.

judge88

CTDHokie,
thanks. im not real sure how much power she has. probaly flirting with 600 on #2 and mid to high 600 with nos. i should have her running again by the end of the week.

John Faughn

If you do not get an answer here than check with APR , I found that the maker of the product has engineered what they want there products to do and how ,
but I would deffinatly do a retorqu after a couple heat cycles ,
try to get the proceedure for torq with an angle gauge , much more accurite than a torqu wrench .

Rolngthun

I don't understand what you mean by "as if they were new"?

DO you still have the paper work? There should be a torque spec for oil on the threads and a spec for moly lube.
Slowly work up to the torque spec. After you have the final torque on them, let it sit for awhile. Then in sequence, one at a time, loosen the nut and retorque to spec. Fel-pro claims that is as good as retorquing after it has been run. Then if your concerned, run it up to temp. Let it cool right down to cold, and retorque again. If I was going to retorque after a heat cycle I would do the loosen first, and torque one at a time proceedure.
I use that proceedure on all my race engines as well as them pesky 3406 heads.

judge88

I don't understand what you mean by "as if they were new"?








the studs had already been in the truck for a couple months so they have been stretched already.

AK RAM

The high horsepower 2nd Gen guys re-torque about every year as their gasket compresses a lot. The studs have pretty good ductility, so they are not stretching as much as one would think and will take lots of re-torques with no problems at all. I would definitely use the ARP molly lube. I would just put them back in, incrementally torque to where you want them, then do a re-torque after a few heat cycles. The gasket will relax a little (3rd Gen gasket doesn’t compress like the 2nd Gen gasket) and the studs will have stretched a little after a few heat cycles. Always a good idea to re-torque at least one time after a few heat cycles.

I just did a re-torque after being in a year. I was really surprised at how loose some of the nuts seemed to be when breaking them loose. Obviously a season of lots of water/meth had taxed the head a good bit. If your shooting lots of NOS or water, it might be a good idea to do a re-torque once a year like the 2nd Gen guys. It could possibly save your head gasket.

Rolngthun

The studs are not going to stretch much, and if they did you would throw them away. In the bigger Cummins head gasket kits they include a guage to measure for stretched bolts. If they show being stretched you toss them.
Alot of them are going to torque to yeild bolts, use them once and toss them.
The big Detroits that use studs on the mains are not torqued to a spec. They have a tool that tightens the nuts and measures the stud stretch. This is the most accurate. It is the stretching of the fasteners as they are tightened that provides the clamping force. The maker of the fastener has it figuired out that X amount of torque should stretch the fastener an X amount.
If the fastener does not return to pretorqued length when loosened, within a reasonable amount, it is considered junk.

nickleinonen

yep. the new engines i have at work use hydraulic tensioning on the head studs and main bearings. by far the best way to tighten a fastener. stretch the stud, spin the nut down by hand snug, then relax the stud. torque done.. and with the proper tool, you could tension all the studs at the same time [the head stud tool for the new engines at work pulls all 4 head studs at once, with hydraulic pressure set to 19,250psi]

AK RAM

So when is that fancy contraption going to be at a BOMB party? I know you could borrow it for a weekend.

For us poor folks that just have to put a head back on the cheap way, a good torque wrench and proper torque techniques will work just fine.

judge88

ok heres my next question. i got my head back today and they had to shave 6 thousands off to get it true. do i need to get a head gasket that is 6 thousands over or just go with a stocker. seems a stock wouldnt be enough since i would be raising the compression even more. if so any ideas where to get a mls gasket 6 thou over

Rolngthun

.006 is not enough to worry about compression wise. Probally not enough to worry about for anything. The biggest concern with a diesel and cutting the head is valve to piston clearence. A good machine shop will know how much they can remove before having to sink the valves.
.006 is not much, the gasket probally has a + or - of a couple thousand.

abc4yew

Yeah but now hes stuck with a Cummins 5.899litre engine. ks

Jfaulkner

I bet your butt dyno will probably be able to sense the loss of displacement.

judge88

do you really think 6 thousands will make that much of a difference.