Cometic - Yay, or Nay?

I have been doing a LOT of research on the Cometic head gasket for my RB20DET top end build.

I have read a lot of bad reviews and a lot of good reviews. I have read that the resurface must be @ 50 RA.

So. Basically. Anyone have any experience with Cometic first hand?

People say that they piss out within 10 minutes of start up. Some say they last forever. I understand prep work. Yet, are the gaskets just shit?

Should I just use stock?

I am the type of person that HATES doing shit twice. Especially being a mechanic. Working on your own car fucking sucks. I’m looking for some accurate advice.

I have O.E Engine gasket kit already. Just have to order MHG and studs. Was going to get to it very soon. Decided to do research…glad I did.

I have no experience with Nissans, but in the DSM’s Cometic are a GOOD gasket, and terrific price…BUT…as you pointed out, preparation is SUPER CRITICAL. Most guys don’t do a good enough prep job, then are surprised when the Cometic leaks. It is a METAL gasket, will hold LOTS of boost, but not very forgiving to surface imperfections…

Well the cometic I used on the s13 (sr) was not a very good fit. The dowel pin holes caused the gasket to sit crooked. I also did not spray the gasket with copper spray so it leaked. I went to a cosworth one and have not had a problem since. And I did not spray the cosworth one.

the rb I build a few months ago used a yonaka (spelling?) and it fit great on the 26.

^^ i had the exact same problem…then changed it to a 1.1mm tomei HG which fit much much better…

+1, heard the same deal from many others about the product, you have to know and follow the proper procedures if you want it to give you the best fit and protection but other than that they are one of the best out there and can handle lots of stress and pressure.

i don’t have experience with cometic. But i was in the same position as you when i was doing my build on my SR in 07’ I kept reading mixed reviews about cometic headgaskets. i just ended up buying a apexi metal headgasket, and that was the end of that. i guess what i’m trying to say is, go with a headgasket that’s had nothing but good reviews.

That’s what I’m thinking now.

Where would I be able to source a Tomei or Apexi for my RB20DET Locally?

Go with a trusted company, Dont cheap out or youll be doing it twice.

i’ve never had a problem with Cometic, but the ones i installed were sprayed and had the buttons removed.

also never had an issue with the ones i’ve sold, but it’s probably a safer bet to spend another $120 and get an Apexi.

Dunno about local but Enjukuracing.com has tomei ones for 264 in varying thicknesses… you could also get ahold of tunerlab.jp in japan… they can get anything

Thanks Chris.

I’ll check that out when I get a chance.

Like Special Edition said…I do NOT want to do this twice.

oh common … its fun. nothing like building an engine you think is fine only to descover you need to rip it down to nothing hahahaha … Fun!.. I got my gaskets from summit. shipped here for 170.

Adam

Contact info for enjuku Say your on Zilvia and that I sent you

Ken Harrison
Enjuku Racing Parts, LLC
Hours: 10:00-5:00, M-F, Eastern Time
Voice: 352-241-8399
Fax: 352-241-8363
Ken@enjukuracing.com
www.enjukuracing.com

or for tunerlab.jp Ive delt with both and had great success… numerous parts for my rb20 including interior stuff and my rb20 harness from tunerlab and picked up my clutch and interior stuff from enjuku

Daryl Henwood
Nikka Trading Japan
http://www.tunerlab.jp

email daryl at sales@tunerlab.jp

Chris…you fuckin rock!

Probably gonna go with Tomei. They have a wider selection for bore and thickness. Plus I trust Tomei.

i got my apexi from bing… couldn’t have been easier to install, no issues boosting 17.5 lbs wherever i go…

Ive used the cometic on my sr, and re-used it no problem no leaks. Never machined the block or head just cleaned it well and used the copper spray.

my new motor has a metal head gasket and has a good seal, no leaks. not sure what HG it is but it works.

If i were to be in the situation again to do a head gasket id just go oem with arp’s hands down. Unless your really pushing the boost…i dont see a point its so much easier to prep the head/block for a oem gasket and know its going to seal rather than crossing fingers with a cometic.

That keeps going through my head now too.
I don’t have plans for big boost any time soon. Yet, in the future…who knows?

So why not get a MHG now? I’ve done lots of composite and metal head gaskets. NEVER decked the block…ever. Head ALWAYS gets machined to a near mirror finish though.

I am gonna talk to my engine guy in depth about this. He laughs because it’s all gravy to him. Yet, this is serious to me lol. I will NOT do this job twice. Even if the HG costs $500. If it’s 100% going to work. I would buy it over any other 99% gonna work.

Keep the advice and idea’s comin guys!!!

Get Apexi… I heard cometic are garbage for sr’s dunno bout rb’s but yea apexi all the way

Thing is. It’s a straight 6. Headgaskets are prone to fail more so on lengthy motors.

That and aluminum to cast. We’ll see.

Going to see my engine guy tonight.

Another thing that would worry me is whether the head and block are of the same metal?

as the engine heats up the head and block expand differently. The oem gasket would have much more give than a metal head gasket.