head stud install question.........LONG

[NCC1701]

Followed the instructions on TBS.com to the TEE. Used loctite 567 on the studs, let it set for a few weeks (not intentional, roller cam install problems).
This past weekend, went to install heads. Used 9441pt gaskets. Whent to torque cycle the arp nuts and washers on the studs. Did 6 cycles. On the fifth cycle, I noticed that the studs had been backing out each time I broke torque. I torqued them in 10 pound increments. I am thinking that when I got up to the 70ft/lbs and higher each time I broke them lose, the stud twisted out a bit. So each time I broke torque to go to the next higher torque value, the studs would back out a little. Well I only noticed this on the fifth cycle. So I got the allen wrench and tightened all the studs back down before I torqued cycled the sixth time. Some of them I got quite a few turns on, but none of them backed all the way out. This was Sunday. As it sits now, the heads are torqued to 90ft/lbs.
Now I am wondering if I screwed up the seal on the studs.
I am not sure I totally understand the concept behind the loctite 567 as a teflon sealer. Is it supposed to act like a rubber gasket when it hardens?? I mean conforming to the exact shape of the treads and filling up any spaces that are present but not glueing itself to the stud??? Or is it supposed to be more like a sealent and glue the studs to the threads???
Hope that makes sense:biggrin:
I would hate to have to redo the head studs, but if I have to I will.
I am going to go pull one head to see how the studs a sealer look.

 

[NCC1701]

pulled the head............

didn't look bad at all. the Loctite 567 seemed to be sealed to the threads in the block just fine. But it appears that loctite 567 is not sticking to the threads on the studs. Should that be the case????
Anyone have any opinions on this???
TIA
Lorenzo

 

[ijames]

I've not used 567 but have used 565 on some things and plan to use it on my head studs when I do them. If you go to Henkel KGaA and surf around they have data sheets on both. They are supposed to set up fairly hard and really aren't meant to keep sealing if you unscrew and retighten the stud after the inital cure. It should stick to the block and stud equally, so maybe there was some oil or grease on the threads? The 567 needs several days to reach full strength - it's only up to about 60% of full strength after 72 hours. I guess during the first day or so at room temperature you could disturb it and have it recover and still seal, but that's a bit of a guess on my part. They are anaerobic sealers so only the little film trapped in the threads without oxygen will actually cure at first. The rest will stay soft a long time, and should do a little recoating if you disturb the stud, but the seal won't ever be as good as that first one when all the surfaces are clean, dry, and oil free. The 565 cures faster, over 90% of final strength in 24 hours, and is about 3 times stronger once cured so my hope is that it will keep the studs from spinning if/when I retorque things. Still only rated at 45 in-lbs of breakaway torque on 3/8" pipe fittings so it's not like the studs will take massive efforts to unscrew .

Given that the motor sat for weeks before you disturbed the studs I'd probably pull the studs and clean everything so I could start over. Couple of hours now, maybe, versus a better chance of water seeping later.

 

[Dr.drivability]

studs

Followed the instructions on TBS.com to the TEE. Used loctite 567 on the studs, let it set for a few weeks (not intentional, roller cam install problems).
This past weekend, went to install heads. Used 9441pt gaskets. Whent to torque cycle the arp nuts and washers on the studs. Did 6 cycles. On the fifth cycle, I noticed that the studs had been backing out each time I broke torque. I torqued them in 10 pound increments. I am thinking that when I got up to the 70ft/lbs and higher each time I broke them lose, the stud twisted out a bit. So each time I broke torque to go to the next higher torque value, the studs would back out a little. Well I only noticed this on the fifth cycle. So I got the allen wrench and tightened all the studs back down before I torqued cycled the sixth time. Some of them I got quite a few turns on, but none of them backed all the way out. This was Sunday. As it sits now, the heads are torqued to 90ft/lbs.
Now I am wondering if I screwed up the seal on the studs.
I am not sure I totally understand the concept behind the loctite 567 as a teflon sealer. Is it supposed to act like a rubber gasket when it hardens?? I mean conforming to the exact shape of the treads and filling up any spaces that are present but not glueing itself to the stud??? Or is it supposed to be more like a sealent and glue the studs to the threads???
Hope that makes sense:biggrin:
I would hate to have to redo the head studs, but if I have to I will.
I am going to go pull one head to see how the studs a sealer look.

How tight did you install the studs? Thats what stage I'm at. I only went hand tight with mine using the GM version sealer. I personally think you'd be fine. If you pull both banks you are buying new head gaskets.IMO

 

[NCC1701]

Here is how I did it.

I installed the head studs with an allen wrench. I used the long end in the stud and the short end to tighten it. That is what the instructions recommended. Using the side of the allen wrench that gave you the least amount of leverage.

Ijames,
Unless i am misunderstanding you, the loctite 567 would not work because you would not be able to ever retorque the heads without breaking the seal that the 567 creates. What about the retorque after the first few heat cycles??? Still trying to figure out where I went wrong??? I cleaned each stud in acetone and then brake cleaner before applying the sealant. This was after i wire brushed off the coating on the threads of the studs. Exactly like the directions on this site.

Still trying to figure this out i DO appreciate your opinions.
TIA
Lorenzo

 

[ijames]

You would have the same problem with the 565 on retorquing, since getting the engine up to temp a few times will greatly speed up the cure rate so I'm sure both would be fully cured before you did the retorque. That's why I'm going to use the 567, so there is less chance the studs will be able to break loose and spin, messing with the seal. If you cleaned the studs with acetone and brake cleaner they should have been perfect, and I have no idea why the stuff didn't stick after a few weeks of curing at room temperature - sorry. Steel is considered a not very active surface so the cure is slower than with other metals but even so ... Was the engine in an unheated garage? As cold as it has been in some places for the last month nothing would have cured .

 

[chrisgarrett]

To answer your earlier question, the sealant is placed on the threads because the studs or bolts extend into the coolant passage. The Loctitie provides a sealant to prevent the coolant from leaking out. I torqued in proper sequence and in 3 cycles-40,60,80. On the final torque I backed the bolt off 1/4 and retorqued. I did not retorque after a heat cylce because that breaks the sealant.

You will find many opinions on retorque. My heads have been on for 2 years with no problems.

 

[Just a Six??]

I never re torque after a heat cycle with studs & GM gaskets. I have never had a problem & my motors & they come out almost on a yearly basis to freshen up Cuz I'm Bored in Winter!

 

[NCC1701]

looks like i'm redoing the studs.......

There is now enough doubt for me NOT to redo them. Besides, the engine is still on the stand, Cant get any better access to the head studs than now. Peace of mind now dictates that I pull them start over and this time torque them while the sealant is still curing.
I do believe that they sealed just fine iniately, but in all the cycling and retorqueing of the bolts I broke the seal.
OH well, live and learn right
besides it will prevent me posting a "water in my oil" post in a few weeks.
Thanks everyone for your thoughts.
Lorenzo

 

[Gary]

Call ARP. It's what they do for a living. But I say Permatex #2 on the block side heads to finger tight. ARP moly on the threads topside and tighten to 70/72 ft.lbs.. Moly causes a lot less friction than engine oil as a lubricant so with moly you don't use as much torque. Again call ARP if you are in doubt.
Gary