Thread: COmetic + 90mm bore

Anyone managed to successfully use a cometic on a 90mm build?

I've had about 3 failures now, and starting to think it's the cometic? Previously the blown gasket caused other engine failures so wasn't able to pinpoint the exact problem.

There's a reason why its called "co-blam-ic".

Ok can you pls get back to me about a PE gasket? Mailed a few times but no reply...?

I was going to ask you in your other thread if you were using a cometic headgasket. hahaha. Yeah Cometic gaskets suck especially the bigger the bore you go on them. They are a shitty designed gasket. Much much better options out there.

If you are still using a DE I would look into the Cosworth Headgasket or the PE gasket that Mazworx sells and be done with it. Also please dont tell me you are using the old style ARP headstuds. If so, ditch those pos' and get the studs from mazworx that are proper studs.

Should take care of the problem your having assuming its not a dropped sleeve.

Ronnie where you been man? The Cometic has been a known mess of fail-ness for awhile now.

I had to check if this post was from 2007.

Odd, I know a lot of the RWD SR guys use the Cometic on bores ranging from 86-87mm without any issues.

While I planned on using a Cometic I may go with another metal head gasket as I haven't started purchasing parts for my build yet.

Waiting for my machine shop to get back with me.

Im sure they arent pushing the limits of them either. while it may be slightly and only slightly better than an oem sr20det headgasket only due to being a stronger material. Its sealing properties and design are flawed, old, out of date and there are much better options out there. Such as the Cosworth and PE headgaskets. For det's I personally love the Cosworth headgaskets. Awesome gasket for the money. PE while more expensive is also a very nice gasket.

I think I may go with the Cosworth, for the piece in mind. Its only about 60 bucks more, so it shouldn't hurt my build budget that much.

You cant go wrong with the Cosworth. Ive been using them for years and not one problem. GE headstuds and Cosworth gasket, 30psi psi of boost from the 60 trim, roughly 530+whp, and then 36psi of boost from my t67 h.o. roughly 650+whp and not a single problem with the gasket holding.

I'm going to be using ARP head studs... Not too many guys even on large amounts of boost have had problems with those...