Cometic Head Gasket success? horror stories? what ya got...post up!

[cdorhout]

i somehow dont believe you, seeing how 3 of the fastest DSMs in the U.S and a 1000hp evo are from (my town) Iowa. and there is no way it was stock. but OEM maybe.

What???? 3 of the fastest DSMs in the U.S. and a 1000hp EVO are from your hometown? Please, enlighten me....Toledo, Iowa is the epicenter of DSM performance....
Modified by cdorhout at 11:02 AM 9/16/2009

[Shocker]

What???? 3 of the fastest DSMs in the U.S. and a 1000hp EVO are from your hometown? Please, enlighten me....Toledo, Iowa is the epicenter of DSM performance....

Modified by cdorhout at 11:02 AM 9/16/2009

Lol +1 I didnt know AMS moved their shop from Chi Town to Iowa..

What I have seen with these gaskets, many ppl on here that have used them have had issues with sealing them. Some of these ppl are very knowledgeable, switched gaskets and no longer have an issue. That is enough to keep me from putting one on my RB.

Just cause this gaskets works on a DSM, doesn't always mean it works on a Nissan.

[boosted98gst]

Yeah AMS is a great place but the title to fastest DSM and EVO still belong to wakeman ohio. Proven aleast for 2k9 it is, someone is always faster. But back on topic id go a diff route and not cheap out on a gasket.

[lexrob]

Ok so what is the best option if oem is unavailable. I was in the situation a month ago did all the research i could and kind of came out 50/50chance with no resurface....

I would have spent more on any other but no feedback as far as using as an oem replacement was really to be found. (as far as for rb's)

[onepuff]

http://www.nismoparts.com/cata...#1696h ... -c...13171

You can get an oem head gasket pretty easily nowadays. You might have to get the whole engine gasket kit but you can always use the other gaskets in the kit. You could also give these dealers a call and see if they can get just the head gasket for you.

[rb25det250sx]

oh well 3 600+ HP DSMs and a 1000hp evo. not to bad and the 3 dsm guys are from and still live in toledo iowa. but teh guy with the evo lives in cedar rapids now. and he is on the AMS site at 936AWHP. but that was last year and had 21lbs springs so was limited to 52psi if i remember right wit a 42r. now so i've herd has a 47r and 35lbs springs.

[boosted98gst]

no offense but 600hp in the drag racing world for dsm's are cookie cutter cars, there are so many high hp cars its not even funny. MY car is almost 950 awhp im a non sponcered racer I have a full time job and to compete with the big boys , is not going to happen for me. I know 600 hp dsm's would maybe compete in the street class and still get rapped. in the Q16 class you better come with aleast full slicks, 1k awhp and a shoot.

[240z4u]

Why don't you guys take your richard measuring contest offline?

[Shocker]

Why don't you guys take your richard measuring contest offline?

Agreed, I thought this tread was about a gasket? Not some Joe Schmoes DSM.

[rb25drag]

I have re-used my Cometic gasket 3 times now with No issue's.

The key is a Mirror finish. Most machine shops FLY cut there heads to surface them. That WILL NOT SEAL a cometic gasket. It leaves small tool marks in the material.

The guy I use has a surface machine that takes Ceramic cutters that actually Cuts Backwards than a normal cutter with results of a mirror finish.

I have never had an issue with his surfacing using cometic gaskets.

This last time I re-used my gasket I sprayed it with Copper coating just to make a Double deal seal. I can put the leak down tester on mine and it will show less than 10% per cylinder.

I say Cometic is Good as long as you know how to use them.

[l0nestar]

Update?

By reputation, I would suggest OEM or Cosworth.

[TimeAttackTheory]

I had a customers car at my shop with a blown head gasket and the static compression was still within the manufacturers spec in every cylinder. But the dynamic compression in cyl 2 would drop. Coolant would only leak into the cylinder during boost. That car drove me crazy

But luckily all of my cometic head gaskets have been holding up with no leaks

[lexrob]

Well 3 wks and yep she is leaking. Slight seep from #1 not enough to show up on stick but ...a problem.

I did not resurface but checked both surfaces and they were in spec. so i tried it arp's no copper spray.

Anyways now im stuck between oem and cosworth. I want to do this one more time and dont have a local shop to handle that kind of "quality of work" or the money right now. Advice...

[neo240sx]

After rebuilding my motor over the summer and using a Egay oem gasket I got about 600 mi on it and the head gasket blew. I bought a Cometic gasket from ebay 170 shipped. Got the head check and cleaned but not resurfaced. I cleaned my block with break parts cleaner and a razor. Sprayed it with that copper stuff.

Long story short I got about 130 mi on it right now. Everything seems fine at 8lbs even with s***ty stock tune.

[rb25det250sx]

has anyone thought about tomei? might be a little pricy, but with the problems you all are having with cometic, then it might be worth it doing a tomei MHG in the first place.

Also not sure if apexi makes one, but might be worht a shot

[StricNyne]

i rock tomei no problems at all and i got for 100 like 4 years ago brand new lol

[lexrob]

Just did a comp test the other day blew 140 across. Put dab of rtv on side of block and no more leaks two days! Ill let you guys know how it goes. I know band-aid but i dont have time right now to change it so. I was going to attempt a retorque but decided against it after comp.. That make like 4 of us on cometic no resurface.

[lexrob]

Just a note ive probly read about more leaking resurfaced block/head motors than nonresurfaced. I mean whats the point of spending $$$$ if its still going to leak. Maybe its just finding the military spec .0000001 of and inch shop that is up to the grade to make it work. heh

[Bluefire]

I used a cometic gasket on a turbo ka i was building. Both block and head were decked at a machine shop I have been using for years. All head stud holes were tapped and cleaned out. I torqued the head down properly with 0 issues using arp hardware. After firing the motor up, I had a massive oil leak from the head gasket. I then changed the headgasket again with a supposedly redesigned gasket from cometic which seems to have fixed the problem.

I have never had issues with apex'i, hks, greddy, tomei, or oem on both decked and non-decked surfaces.

I am also not a fan of cosworth headgaskets either. I've had weird knocking issues with them...

[flatrate]

just an update, i have gotton the motor build done and running in the car... about 400 or so miles and not a single issue. No leaks smoke etc.. cometic seems to work fine for me so far... i will be retorquing the ARP's at 1k miles

im sure its the lack of a straight surface as to why people are having failures...straight 6's are more prone to that anyway due to be so long and its easy to store the head incorrectly

[sickness14]

Has anyone had any experience with a Tomei RB25 head gasket? I had a cometic, then a cosworth gasket but on the next build, im not sure. just wanted some opinions.

Thanks!

[rn240sx]

I had my motor built 5 yrs ago, block and head both decked... Used a cometic and never had an oil or coolant leak between the 2... But then a few yrs after the build, one day i leave the driveway and my water temps went SKY high and very quickly, go back home and to find out i was low on coolant.. But never saw any leaks..Few weeks go by and the same thing happens every so often, i would leave the house and within 3 miles the temps went sky high as if i had air pockets.. Go back home and find out im low on coolant AGAIN..!!! This went on and on for months and i was clueless to know why i kept loosing coolant, yet i had no leaks and kept bleeding the system, draining it, filling it back up and even taking it to a mechanic to have them "properly" drain and flush the system... And a few weeks again the same problem...!!!

Just last week i ran into a bad spark plug, went to take it out and it seized in the head and snapped while trying to remove it... So i had to remove the head to have the machine shop remove the bottom side of that plug that was still in the head... Just to find that when i pulled the head off and inspected it, i notcied that the # 3 cylinder was so much cleaner than the other 3 sides.. and to my eyes i noticed that the headgasket had damage to it on the # 3 exhaust side... some of the black material was missing and thats when the machine shop guy said, thats where the coolant was jumping over into the combustion chamber and burning away, which explains why that cylinder so clean and thats why i was low on coolant every so often and why my spark plug seized due to coolant getting into the threading...So now ive got my head back, spark plug removed, vacuum tested the valves and they came out ok, and he lightly shaved the head to remove the left over cometic hg impression...

So, just a nice little story for you guys about the cometic... not sure what caused that hg failure but it did and only in that little spot..

[boosted98gst]

I just met a local guy on his 4th gasket on his KA he now is going to just try and run a stock gasket. The ka made 409 whp but everytime was eating coolant , Everytime I looked at his old gaskets that he kept they was jumping at different spots. I really feel bad for the guy hes spent so much money on it for it not to even seal half way decent.

[rn240sx]

I just met a local guy on his 4th gasket on his KA he now is going to just try and run a stock gasket. The ka made 409 whp but everytime was eating coolant , Everytime I looked at his old gaskets that he kept they was jumping at different spots. I really feel bad for the guy hes spent so much money on it for it not to even seal half way decent.

i feel his pain, but not as hard considering he has been thru 4 of them, this was only my 1st. And its funny how his coolant was also jumping.. and my motor made 424 whp...

i think this time im going with a felpro and seeing what happens.

[boosted98gst]

i feel his pain, but not as hard considering he has been thru 4 of them, this was only my 1st. And its funny how his coolant was also jumping.. and my motor made 424 whp...

i think this time im going with a felpro and seeing what happens.

He bought the felpro tonight and started to take the head off. I did look at the gasket and it seems to be a fairly beefy gaskey with like metal o ring around the cly. With proper head studs I felt this should seal pretty good. I will keep you guys updated and see if cometic is really that hard to seal, it seems like god himself could not machine the surface that straight.

[neo240sx]

So after thinking my cometic head gasket was working I add new injectors and turned up the boost and FAAAAIIIIIL. Now my engine runs on coolant and gasoline!

So the question is: What gasket does work so I dont have to change it again?

[neo240sx]

I think cometic works on hondas because they come stock with a MLS gaskets. Most nissans do not. At least my oem one didnt.