Cometic head gaskets

[Try Me]

Hi again. since im sitting here in front of the computer for a moment i figured i would check on this. I bought a set of the MLS head gaskets from cometic and put them on my truck. after about 200 street miles and 3 runs at the track, they managed to blow on both sides. We called Cometic and talked to them about the gaskets and they stated that those were a new design when i purchased them and that they should not have let go under 19 lbs of boost. Cometic then was happy to send me two (2) brand new sets of mls head gaskets, some shop banners, hats etc. I was thrilled at this since the first set was over $100. I took my heads and had them give them a light skim cut to ensure that they were perfectly flat again, and am getting ready to put the truck back together. Has anyone else had any experience with these gaskets. I know people who have used them on small and big block chevys without a problem, but no one has done them on a turbo or supercharged car.

 

[hamrhead]

I've had them on my Sy for quite a few months now - probably a few hundred miles with plenty of boost every time I drive it. They're stilll holding.

I do seem to have a disappearing anti-freeze condition. Not very much though. I'm guessing it's getting into the combustion chambers as there's no signs of it in the oil. I'm wondering if the head gaskets are the culprit, or just the lower intake?

 

[myclone]

Do a search for cometics HGs on the buick board. A fair amount of ppl over there have used them/tried them with mixed results. The consensous(sp?) seems to be that sometimes they leak while other times they dont. Either way most posts Ive read the leaky ones get fixed by adding one or two of the GM "stop leak" pills.

Dont kill the messanger, as Im just passing on what Ive read and I dont have first hand experience with the cometics or the GM stop leak stuff. :-?

 

[Windedv6]

I have been running them for two years and no problems. Was running 28-30 lbs of boost wiith my stealth turbo. Running about 25bls on my current 72GTQ setup.

John

 

[bigtime]

I have them on my 442 (SBC) with 22lbs of boost, no problem. as a matter of fact I sold the heads and put another set on with the same gaskets and no problems here. You have to make sure your heads are cut to a #50 RRA finish. Amost smooth.
I have them on my good Ty engine but have not put it in the truck yetyet.

 

[jwaller]

I've built 3 trucks now with cometics and not a single problem high hp and boost both steel and alum heads. what studs/bolts and what torque are you using? u torqueing in the right pattern?

 

[Maxtor]

I put Cometics in the Stokes Sy this summer. Since then, I've put probably 200 miles and several 20+ psi pulls on it with no problems at all.

 

[JSM]

I put Cometics in the Stokes Sy this summer. Since then, I've put probably 200 miles and several 20+ psi pulls on it with no problems at all.

Slow down, don't rack up the miles that fast.

Of course I have put 0 miles on mine in past 2 years so I shouldn't say anything.

 

[hamrhead]

Went to www.TurboBuick.com, signed up, then did a search or two.

Found this part number for the GM Stop Leak Pills ---> #3634621

I'm going to pick some up this week and give it a try.

 

[Try Me]

Cometic head gaskets

Well, ive got the truck back together again. i havent had it out enough yet to really be able to tell, but so far so good. I used my same arp head bolts over adn torqued the same pattern that i got from my handy little felpro performance gasket book. Im hoping that they hold up, ive heard alot of good things about them. If not , its still worth a try. at least the company stood behind there product.

 

[ghettosled]

when you removed the heads after the gaskets blew, did you by chance do a torque break away and see if any of the hardware losened up? Could also be detonating which causes the gasket to push out.

 

[93ty475]

did cometic gaskets come with lines impressed on them? i am to reuse a set that i breifly ran under some l35's on some vortecs now...i can't recall if they came that way or did they get the imprint from the brief use...so are they flat like coppers when new or do they come with lines all over them around water ports and such? tia