Thread: Cometic head gasket defects ??

so your still having the same problem even with the oem gasket. Yeah you definetly need to use some new bolts or headstuds. You might as well go and purchase some anyways. Have you had the head resurfaced as well cuz if it overheated then its a big possibility that the head may have warped a bit. Id say at the least get some new stock headbolts and get a Cosworth headgasket. The Cosworth hg will work for both the fwd and rwd sr20's and it is definetly a piece of artwork. That gasket is strong as hell. There are a couple companies in the US that sell them. The one i got mine from is in California. Just google it and try to find a company that sells them. get the 87.5 mm X 1.3mm thick gasket. they come in 1.1, 1.3, and 1.5 i believe for the thickness. Dont worry about using the 87.5 mm gasket on a stock bore, It works beautifully and the fitment is awesome. It has one of the strongest firing ring, oil passage and coolant passage clamping forces out there.

Yeah, this engine has been opened like 3-4 times already all of them using the same head bolts. This time, the head has been resurfaced, the block surface has been properly checked and it was fine, brand new OEM head gasket.

It is blowing water out of the water reserve tank, the thing is, it is not doing it when we drive it out of boost, so thats where I think the problem is head lift, that later on ruins the fire rings (like the cometic), and that the bolts should have been checked before reused them... Its got to be head lift since its blowing water only on boost, and the car is not throwing white smoke thru the exhaust.

Either that or AE86DET has really bad luck and the guy that resurfaced the head messed it up lol.

My Cometic lasted about 3 weeks, not even on a high boost build either...was on my 11.8:1 N/A DE. It just fell apart between the bores, was torqued to OE specs using OE bolts. Wen't back to a Nissan one and it's been fine since.

^ I *think* our headbolts are torqued to yield, which means that they are torqued so that they stretch a little bit. by removing and retourqing they strech even more, compromising their integrity.

Your problem is probably that they are now just stretching even more.
Gte new headbolts and see what happens.

^^^ Correct. The bolts are TTY. They cannot be reused because the bolts go into plastic stretch when you torque them down. They don't ever shrink back down. Always use new head bolts unless they are re-useable (studs)

seems like we are on the right path to finding the problem too bad it cost me another head gasket and a new stomach ulcer to find out. but really shoulda known better and replaced those #$@^* bolts as part of maintenance. now i know its required. lets see what happens with another week of down time.