so am i proper f**ked? (head gasket?)

[sidewaysil80]

so my old gt2871r setup was pushing 21psi, (stock bottom end). i de tuned the setup and am now running a gt28r at about 13-16psi. now heres the question, the headgasket was a greddy .88x1.0mm is that too big of bore considering i'm still using .86 pistons? i mean i know the .87mm will slightly drop compression but since i'm 2 sizes larger should i get a proper sized headgasket? is it robbing alot of power you think? as always, thanks in advance zilvia!

[240sxjohny]

Thats not cool man ??? why are you abusing your car ??? your probably gonna get a leak !!!!!!!!!!!!!!!!!!!!!!!!!!!!! you should get the proper size to make it nice and snug and you may raise your compression a bit more =D poor car =[

[steve shadows]

ok...

You have to have AT LEAST an 86.5 mm bore, because this is the factory BLOCK size.

The HG is measured off your BORE size of the block, 87 is fine, 87.5 is fine, 88 is ok too, but I would try to stick to 87.

Why did you buy a greddy HG anyways? They are crap

Sell it or throw it in the trash and get a Apexi with 87.5 bore.

[j87w]

I'm not sure what steve means. The stock bore is 86mm with a 86mm stroke.

[jspaeth]

I'm not sure what steve means. The stock bore is 86mm with a 86mm stroke.


Some are sized weird too....I read (on FRSport) that an 86mm Apex'i is actually 87mm and an 87mm is actually 88mm.

Anyone have any comments on that?

[lewisfk]

go to enjuku!

[rc1honda]

Some are sized weird too....I read (on FRSport) that an 86mm Apex'i is actually 87mm and an 87mm is actually 88mm.

Anyone have any comments on that?

Yeah i think your right about that. i think it's to make sure you get a proper seal and for overbored motors. you can run a bigger bore headgasket and it will be fine and still have a good seal. You can never run a smaller one tho, i just think it's to make sure people get a correct size HG.

[jspaeth]

Yeah obviously to small and you have the headgasket hanging into the cylinder, plus the "rings" on the HG around the cylinders are inside the cylinder.

Anyway, I thought stock was 86 mm too.....

[sidewaysil80]

ok...
Why did you buy a greddy HG anyways? They are crap
Sell it or throw it in the trash and get a Apexi with 87.5 bore.

lol, i keep hearing that. i ran 21psi on it consistently and beat the crap out of it when i had the gt2871r setup. the head/block were milled and decked as well as arp headstuds. at this point i'm only going to be running 16-17psi TOPS. so i'm not to worried. but steve thank you very much for the advice i appreciate it. i just want to make sure its not going to rob power or cause any running issues. i just dont have resources/time to get the head re milled and swapped to a new one. UNLESS its a big issue. thanks!