I'm putting the motor together next week and will either be using ARP head bolts or studs. With the studs, can you get the heads off the motor in the car? Or will it hit the cowl in the back? I'll use bolts if it is a clearance issue. Also, I'll spray the cometics with copper sealant, but will I have to heat cycle and retorque them to make sure they don't leak? Or torque to spec and roll with it? Thanks.

John

 

yes you can get heads off with studs in the block.....

I personally wouldn't use copper sealant as the stuff is a PITA if you ever want to remove the heads for some reason.....

you should retorque though 99.9% of people don't and never see a problem......


edit:

1) I missed the part about them being Cometics (thought Felpro/fiber style for some reason).....don't use the copper spray on the Cometics.....the really nice thing about Cometics is that you can reuse them (remove the heads) but if you spray copper on them, you will not be able to pull the heads without bending the gasket and as such will trash the gasket....

2) no you do not really need to retorque Cometics.....they don't crush like fiber gaskets.......the bolts however could use a retorque as they heat cycle (again.....99.9% of people don't)....

 

You should retorque, but I did'nt. You will get yes or no's on Permatex copper spray on cometics, I sprayed very lightly and had no sealing problems, used to steel shim small block gaskets, I guess.

 

Yeah, the cometics will get spray. I'm not sure I'd reuse them if I ever pull the heads anyway, just paranoid I guess! I'll go back and retorque more than likely as I'm that ****! Thanks for the input guys!

So the heads will come off studs with the motor in on a fbody?

 

Yes, heads will clear studs in an f body

 

what makes the studs better than the bolts?

 

Hey john, I used the .040 cometics with arp bolts. I didnt put the copper gasket maker spray on because of the PITA job the next time I take the heads off. I have heard alot of people say to retorque but I havent yet, and have no leaks. As far as studs or bolts, I think the main advantage is going to be saving the block threads with studs. Im sure the clamping force is going to be a little better with studs but not enough to make a difference. I guess we will find out after you flog the crap out of the car on the dyno!!


Question to forum
if the cometics do start to leak are they totaled. I read in an earlier post that cometics are reusable, so could you just re torque the head? No problems yet just curious.

 

Good to have you on here Nate! We will find out in about 4 hours I guess! If it is gonna leak it will do it on the dyno.

 

I don't know anyone that's had problems with cometics leaking, with or without copper spray. You shouldn't be so paranoid.

 

If your Cometics are brand new, I wouldn't use the copper spray. I've never had a leaking problem with new Cometics w/o spray. I just reused my Cometics and DID use the spray, no leaking problems. I hope I never have to pull these heads again!

I'm not sure but I think the LSx in a C5 sits back a little further than an F-body and still I have had no issues with the ARP studs. If you ever plan to pull the heads again, I would definitely go with the studs. Just the fact that you don't have to clean the head bolt holes again is worth it!

 

They stay in the block so you don't risk damaging the block threads and you are sure of the torque readings since they are in place when you torque.

If heads are removed and installed with the engine in the car, there is the risk of scratching the heads. Just be careful.

 

There was a post in this section a couple of months ago where someone had ARP studs with Cometic gaskets and they leaked coolant bad (before the engine was started). He took them off, sprayed the copper sealant and the prolbme went away. Should come up under search.

 

Just search for cometics on here and you will find some.

gojo,
thanks buddy! that is what I thought just wanted to make sure.

 

a lot of the leaks come from imperfections in the block/head which allowed paths for the coolant to get out......

ex: if you have a scratch/poor surface from machining in the block, steel gaskets will not "fill in" the scratch like a fiber gasket would.....



I personally have had my heads off upwards of 10 times and the same gaskets are still like new.......


studs are better for several reasons:

1) you are not running bolts in and out of the aluminum block
2) they provide a more even load
3) they provide a more accurate torque
4) are often made of stronger material
5) act as a guide to place head on the block (big dowel pins)

studs > bolts

 

I used copper spray on my new Cometics to play it extra safe as I'm more concerned about leaky heads than having to shell out a few extra bucks the next time I take off the heads. It's all up to preference.