Cometic Headgasket Install

[Powerlinefixer]

My headgasket started leaking out the back drivers corner several years ago. Since I'm putting my TIII back on the road I figured I better get it fixed. I installed the Cometic MLS gasket from FWD Performance yesterday. I checked the block and head for flatness and both were good (not more than .003in). I had my Dad (retired engineer) check the finish and he said it was about 20-30RA at the very most. There were some minor blemishes on the head, but none of them were concerning.

I have installed literally HUNDREDS of MLS gaskets on the Chrysler 2.0/2.4 engines and I always used some kind of sealer, usually Mopar Gasket Sealer but sometimes Permatex Copper Coat. I never had one come back leaking. Mopar says the sealer must be used on Mopar MLS gaskets. Cometic says to install their gasket DRY?!?!?!??!! This is one of the very few times I've had a serious concern with the instructions provided with a product. Maybe dry on freshly machined parts, but I can't imagine not using a sealer on used, clean parts. I used Copper Coat liberally on my headgasket to help seal the slight imperfections on the sealing surfaces and to help eliminate temperature differences between the block and head.

Any info? Did I screw up bigtime? How have the MLS gaskets worked for you all?

[xtrempickup]

i have a 3 layer Cometic on mine with no issues for over 6K miles and ive run 27Psi on it

[Powerlinefixer]

Quote:

Originally Posted by xtrempickup i have a 3 layer Cometic on mine with no issues for over 6K miles and ive run 27Psi on it

Did you use any sealer?

[xtrempickup]

i think only regular gasket sealer

[rx2mazda]

I have a 4 layer cometic that was on the engine when I took it apart for the first time. I cleaned it and the block - had the head resurfaced and then sprayed the gasket good with copper gasket sealer. I have had no issues, boosting up to 22psi. 25+ coming soon.

[Pat]

I've used the copper sealer with them also...no problems yet!

[moparfwdsleeper]

I was turned onto the copper sealer by Jackson.

Cometic without a sealer, doesnt seal(didnt for me atleast). Things come off easier and quicker when you have new bolts also


**8V head, was off less then an hour!

[mopar2ya]

I got the very first MLS gasket for the 2.2s and I installed it dry as per COmetics instructions. It never leaked for several years running 25 psi. I reused it 3 times and only used copper spray when I reused it.

Now my head and block were surface to RA18, this is absolutely ket to using a MLS gasket. Smooth and flat....with some ARP..

[moparfwdsleeper]

the block and head had just been rebuilt(flat, straight and pretty). ARPs(of course). I dont know what the surface was though...

[Ondonti]

Quote:

Originally Posted by mopar2ya I got the very first MLS gasket for the 2.2s and I installed it dry as per COmetics instructions. It never leaked for several years running 25 psi. I reused it 3 times and only used copper spray when I reused it. Now my head and block were surface to RA18, this is absolutely ket to using a MLS gasket. Smooth and flat....with some ARP..

+1

When I had to pull the heads I copper sprayed my cometics. It wont hurt to spray them the first time, but after you pull them the viton sealer gets torn up.

[glht_omni]

i had my head milled .015" and surfaced to ra 25. i have the thicker 5 layer MLS. i sprayed permatex copper spray on thick and used arp head studs. i have only put 1000 miles on it, i left the block in the car and wetsanded the deck as smooth as i could as jackson (lotashelbys) advised me to.... i listen to him because he has 11 running t3 motors.