Arp Head Studs

[tom yuenkel]

What is considered to be the best way to seal the stud when installing in the block, silicone, teflon tape?

[AndyL]

I used teflon tape, so far so good!

[john8662]

Some here think letting them "rust" in works...

Personally, I'm not fan of head studs.

But, to seal them I had luck with using Permatex thread sealant (hi-temp) that's at the auto store in a small tube (as small as thread locker).

Apply thread sealant on threads, install ALL studs into the block then install gasket (a free TIP not mentioned by others) then the head.

Gives you the opportunity to wipe off sealant off deck surface before applying the gasket.

Saves you some grief :rolleyes:

Cause.. Well.. ARP doesn't mention this necessity either.

Finally, Head studs CANNOT be re-installed on heads in chassis, due to above mentioned issue (risk).

Teflon Tape? Hmm, possible, I'm not going there though...

J

[DickWells]

:) I know from experience that teflon will deteriorate, when used to seal a fuel line for a building which uses kerosene in the furnace. Egine oil and high heat do the same? Don't know.
Also, I didn't see it mentioned here, but I assume that you chased the threads with a tap before installation of the new studs? It's mentioned a lot in the DP r&r guides. Just a thought.
Good luck.
DW:)

[AndyL]

DW, did you use the "Pink" teflon tape? There are different kinds for fuel type oils.

[JohnC]

IMHO, Teflon tape is for plumbers.

Problem is if you disassemble the joint you get tiny threads of teflon going everywhere. Especially bad for fuel systems.

YMMV...

[AndyL]

Each has advantages:

Using paste means some will end up in the oil and coolant, minimal, probably no adverse effect, but who knows! Paste also requires you remove all engine oil/water, otherwise the paste doesn't "stick" to the stud or threads. As John said, paste also seems to soak into the gasket and surrounding area, however I've taken apart several engines with paste and it never one seemed to cause a problem.

I've started using Tape because its cleaner, no contamination, the container doesn't dry out, can be applied on "wet" threads.

In either case, i've never once had either leak!

[JeepSJ]

Don't use tape for the reasons mentioned above. The teflon based paste is what you want to use. ARP even makes it and recommends it for any of their bolts that thread into a water jacket. That is what I used on mine. There is nothing that needs to "stick" to anything - it will seal just fine in a hole that is wet with oil or coolant. If you are worried about it, just hit the holes with a shot of brake cleaner before you install the studs.

[DickWells]

I used plain old white teflon tape. Never did get those threaded joints to hold completely dry for any length of time, with kerosene. The oil delivery guy told me that would happen, the first time he filled me up. They never leaked very much, though. Twelve years in the gun shop, with that glorified pot-burner from a mobil home, and I never did actually pull the joints all apart and re-goop all the threads, just the worst ones. Just wiped things up once in a while.
DW:)

[ronniejoe]

Personally, I use Loctite 270 or equivalent to ensure the stud doesn't move when torqueing the nut. It seals and locks the threads. I also recommend installing the gasket first before the studs since the projected positional error of the studs sticking out of the deck causes interferences with the gasket holes. It is very difficult to install a head gasket over the studs without damaging it.

[gmctd]

I use Loctite, also - the stud should not be allowed to turn in the block threads, which is one advantage of studs over bolts - the block threads get mainly compression stress, with minimal rotational torque stress.

Reduces distortion in the deck and upper cylinder walls, unlike head-bolts - lock'em if ya got'em..................

[john8662]

Loc-tite on the threads isn't a bad idea and shouldn't harm the gasket if a little gets on it with the gasket on the deck.

Use of the Permatex sealant in the right place works.

One small bottle did both sides.

You only need to put the thread sealant on the last three threads, Just enough to where when you tighten it in the block that it makes just a small ring around the fastener and if you get your portion correct, it won't squeeze out and will just say in the counter sink on the deck.

If you put the sealant on the beginning threads, you'll squeeze the sealant off, it won't stay on the threads where you think it will. The threads are fairly tight.

After the studs are installed and the amount of sealant has been wiped off with carb cleaner off the deck, then loosen the studs about 1/2 turn from where you bottomed them out, leaving them slightly loose.

Remove the two studs from the deck that have the positioning dowels around them.

Position the dowels on the deck to where the gasket will go over them, because one hole isn't perfectly round (neither is your inserted dowel).

Carefully install your gasket, because the studs are loose the positioning will now allow you to get the gasket over them.

Once the gasket is bottomed out on the deck then install your cylinder head, once again leaving the studs loose.

Position your heads for play.

Insert the two missing studs with some sealant on the threads as you did with the others. No danger of getting sealant on the gasket here because of the dowel in the deck.

Hand tighten all the studs with a "T" Allen Wrench.

Proceed with your torque sequence.

You can also coat the washers with the sealant on both sides and install them all on the studs on the heads. Then take a dab of Moly Lube on the threads and then install the nuts.

It's a LOT more work for sure.

This sequence should provide reliable service.

J

[Kennedy]

Here's how I was taught:

Apply a semi liberal coat of Loctite PST to the threads and run them in then out then in and then out. The key is to work the sealer into the entire thread surface. Redistribute the excess sealer back into the threads, and run in. When done you should have a minor "anthill" at the stud to block interface. I believe it would be best to do this with the gasket on the deck as it's tough to guide down over the studs. Handle the gasket like a phonograph record and do not touch the surface.

I would firt fill with water just in case and a "Cadillac tablet" or two wouldn't hurt also. This way if there is a leak it will plug and water will not be nasty like glycol.

When I did the engine in my 96 I had a TON of problems with leakage. I simply smeared and screwed them in. I've had pipe threads leak also. Doing the in and out thing really seems to help distribute the PST and works well...

[JeepSJ]

I also recommend installing the gasket first before the studs since the projected positional error of the studs sticking out of the deck causes interferences with the gasket holes. It is very difficult to install a head gasket over the studs without damaging it.

Yeah, I could have use those words of advise when I was putting mine together! But, I was smart enough to stop after only ruining one gasket.

[tom yuenkel]

When I built my engine in late summer I used standard "white"teflon tape on the studs and installed them in cleaned threads, they threaded in nice and it seemed to me to be adequately sealed. I now notice that a drip of coolant forms on several of the ones I can see on both heads and naturally I'm a little more than bummed. My thought is I'm going to have to pull it and correct the problem. Do most of you agree? I think I'm asking for trouble if I don't