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View Full Version : cometic headgasket question reuse?


89s13silvia
06-28-2008, 02:13 PM
ok so I recently built my motor and now i've ran into some problems with seating the rings. Long story short I'm tearing her apart again. I'm wondering if i can reuse the metal cometic headgasket or do i have to buy another one? I've heard they come in only one size of bore and i am currently stock 86mm now and will be boring out to prob 86.5mm so I'm wondering what i should do?
I have all arp studs so I should be fine there and i'm going to buy a gasket set. The HG has maybe 4000kms on her....


thanks for your help
chris

Bigsyke
06-28-2008, 02:36 PM
Ive heard alot of horrible experiences with their HG's. I will always will use OEM's

jsasrsr
06-28-2008, 02:54 PM
greddy has theirs at 87mm i believe... but tomei is the way to go! cometic has a lot of bad stories that go with it...

89s13silvia
07-01-2008, 05:51 AM
Well i have heard horror stories about the apexi ones aswell. I am just wondering if anyone has reused them before as i would assume it should work but I'm only assuming here.

thanks
chris

sidewaysil80
07-01-2008, 06:57 AM
nope never tried...i'm using the greddy metal one right now and it MAY be causing a compression problem...but i'll have to get back to everyone on that. hopefully i fixed the issue this past weekend. but yeah, in the future i'm def going oem.

Chrischeezer
07-01-2008, 10:21 AM
Ive heard alot of horrible experiences with their HG's. I will always will use OEM's


OEM???.. are u crazy? yeah good luck with a paper head gasket pal

you can reuse a cometic head gasket as long as its not warped or broken or whatever. i have done this many times with no problems.

however i have had problems with a HKS head gasket.

s14unimog
07-01-2008, 02:13 PM
this thread just made a bunch of people go.

FUCK! Which one do I get???????

HKS....sucks
Apexi....sucks
Cometic....sucks
Greddy....so far good
Tomie...so far good
stock....FTMFW (apparently):ugh:

Lurpin
07-01-2008, 02:38 PM
this thread just made a bunch of people go.

FUCK! Which one do I get???????

HKS....sucks
Apexi....sucks
Cometic....sucks
Greddy....so far good
Tomie...so far good
stock....FTMFW (apparently):ugh:

Yea I am kind of confused now, because i was going to buy a cometic HG for my ka24de rebuild. Now I'm not so sure. Can some one shed some light on this please.

s14unimog
07-01-2008, 02:39 PM
see^

I used JB weld and it seems to hold up. haven't driven it yet tho!

500rwhp here I come!

Cash
07-01-2008, 02:40 PM
Use caulk. lots of caulk.

Lurpin
07-01-2008, 02:43 PM
see^

I used JB weld and it seems to hold up. haven't driven it yet tho!

500rwhp here I come!
tell us how it runs

DreamN
07-01-2008, 02:45 PM
Usually the horror stories on the cometic are from ppl who either never had the block and/or head sent out to a machine shop to get them perfectly even or never torqued the damn thing down properly. Sure there are always those who do everything by the book and beyond and still end up with a leaking headgasket, but I feel that every manufacturer sends out a lemon sometimes.

Lurpin
07-01-2008, 02:49 PM
Well i try and do everything by the book. So I think i will just go with the cometic head gasket, and tell you guys what happens.

DreamN
07-01-2008, 02:52 PM
Also, don't be afraid to ask what cometic recommends to torque down the sucker at. If I remember correctly it might be 10-20 lbs/ft more than OEM.

Lurpin
07-01-2008, 02:55 PM
Also, don't be afraid to ask what cometic recommends to torque down the sucker at. If I remember correctly it might be 10-20 lbs/ft more than OEM.

Thats a good idea. I think I will contact them soon about that then. Thanks for the tip :)

EDIT: Do you think they might put the specs for how much to torque in the packaging?

DreamN
07-01-2008, 03:02 PM
I would guess they would or just tell you to follow factory specs, but I'd rather hear it from someone who works for the company and have his name on paper with the time and date I spoke to them incase shit hits the fan. Being cautious never hurts when building an engine :bigok:

whereda40at
07-01-2008, 05:45 PM
Well i have heard horror stories about the apexi ones aswell. I am just wondering if anyone has reused them before as i would assume it should work but I'm only assuming here.

thanks
chris
i have an apexi one with my 2.35L sr and i dont have one problem with it. i also have been boosting 20 psi on it.

LigouriRd
07-03-2008, 01:29 PM
Usually the horror stories on the cometic are from ppl who either never had the block and/or head sent out to a machine shop to get them perfectly even or never torqued the damn thing down properly.
-That is exactly it, the cometic head gaskets call for practically a mirror finish on the block and the head. Without that it will leak. I have used two so far (blew my motor up once) and have had no problems with either leaking...I did use a little spray copper on both sides though. Back to the original question: Do not resuse, not worth the chance of it leaking.

PS: Multiple people have used felpro head gaskets up to around the 400hp range.

white92_s13
07-03-2008, 01:42 PM
as with any metal h/g its recomended to resurface cyl and block.

ive used a TRD h/g in my ae86 and i currently have a cometic h/g in my built 4ag running 12:1 comp and it does fine.

dont reuse

golfer17
07-03-2008, 03:01 PM
If it was me, I wouldn’t bother taking the chance of reusing it, I’d just buy an Apexi and call it good, but it really depends on how much your time is worth to you. For me, when it comes to anything inside the motor, I’ll spend all the money it takes to try and make sure I don’t have to open it up again (I’ve done enough of that).

this thread just made a bunch of people go.

FUCK! Which one do I get???????

HKS....sucks
Apexi....sucks
Cometic....sucks
Greddy....so far good
Tomie...so far good
stock....FTMFW (apparently):ugh:

Everything I've read and everyone I’ve talked to has recommended Apexi, and after getting one and taking a look at it, I know why. The gasket is definitely top notch quality and has an excellent fire ring seal (something the cometic doesn't have). I’ve also heard good things about power enterprise and read some good stuff about the cosworth, but I wouldn’t touch any of the others.

Usually the horror stories on the cometic are from ppl who either never had the block and/or head sent out to a machine shop to get them perfectly even or never torqued the damn thing down properly. Sure there are always those who do everything by the book and beyond and still end up with a leaking headgasket, but I feel that every manufacturer sends out a lemon sometimes.

I had my block and head both shaved as well as the new oil pump assembly I put on it when I built my motor using a cometic headgasket and it was leaking coolant so bad I had to fill it up every day. I’m not exactly sure it was the gasket that was leaking however, as everyone of the valve guides was leaking oil as well, which makes me think that they were not pressed in correctly by the machine shop and thus could have cracked the head somewhere and caused the coolant leak. However, what does lead me to think that it could have simply been a faulty headgasket is that when I tore it apart, the cometic gasket was missing a pretty good size chunk of metal from one of the layers, right around the fire seal. Now there was no mixing of oil and coolant that I could tell, and the car ran very well, however, that little missing piece (and the overall quality/design of the gasket) was enough for me to never buy another cometic product again.

nismo tuned s14
07-03-2008, 05:15 PM
i have a ka-t boosting 12-14psi daily. ive been running the cometic head gasket for 1 1/2 years without any problems. it did, however, leak when i started up my engine for the first time. but after that it was fine

loveskylines
07-03-2008, 05:41 PM
i've used power enterprise 3 times over and still no problems... no gasket maker crap needed. my buddy put together a 500whp sr20... took it apart once still no problems and he beats the shit outta his motor...

lil bit more pricey but def worth the peace of mind.

better cooling with the gasket too!

TEALSQUEAL
07-06-2008, 06:30 AM
Cometic head gaskets can be reused again and again; I remember when I worked at Kintner's an old mustang shop in southern Indiana we reused Cometic head gaskets again and again on the shop racing motors and those were 16.5:1 nitrous motors putting out well over the norm even if you cut that power in half for just 4 cyl. I currently run a cometic hg in my SR and have for over 3 years at 19lbs. w/FPbig28, cams, etc. and had no problems whatsoever.

Also a friend of mine has reused his cometic HG 5 times in different H22's over the years from high compression nitrous set-ups to his latest turbo set-up. The biggest factor is proper block and head preparation; Make sure the edges are sharp and the hashes are present in your prep-work and use your common sense does that hg look like it will seal again, is there still springiness to the steel, is it screwed up from improper installation the first time? Etc.