two40guy

I bought a built block off a friend and i finally got around to ordering my upper gasket set so i bought a OEM s14 sr gasket set but it wasn't until i opened the box and started looking at it until i realized the block is bored 20 over.. am i going to have to get a different head-gasket? or could i possibly use the oem one? this is my first encounter with a bored block so I don't got a clue.. i searched a bit and found some people saying they've done it and its fine and other people saying you should get a different head gasket. any input would be sick i just want to get my motor together.. thanks

Pro ViZIon

That one won't work. I think apexi makes bored headgaskets. Just look for some on a performance parts website.

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1990 Nissan 240SX w/KA24DE - New project
1984 Mazda RX-7 GSL-SE 13B

two40guy

I think it will now. Cause after talking about it stock pistons are 86mm id need an 86.5mm headgasket but after taking a micrometer to the headgasket I got measurements of up to 87.02 I believe.. def over 87mm so I mean I'm gonna measure the walls to be sure but I don't see now why it wouldn't work.. as long as the gasket is smaller than the cylinder wall ill be good. Make sense? Cause I don't see how it would fail its a genuine nissan HG I'm surprised the gasket is off by over a mm o.O but it works in my favor this time but once again any input would be sick

[email protected]

the oem one wont work. you NEED an 87mm bore head gasket and whatever you do DON'T buy cometic! get a cosworth

statickx991

gotta get a over sided one

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im a f18 bro

two40guy

Attachment 24493

okay not trying to be a douche and argue.. im just trying to figure out why exactly the oem one wouldnt work. as you can see all the bore sizes are 87mm but still with wiggle room.. i got it up to 87.03mm and still was able to pull it out freely. there is no possible way this would work? thats all im getting at now. just trying to learn.. if i have to buy a new one.. ill have to buy a new one.. no big deal just why buy one if this one is fine?

Pro ViZIon

you normally want your headgasket a little bit bigger than the cylinder bores.

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1990 Nissan 240SX w/KA24DE - New project
1984 Mazda RX-7 GSL-SE 13B

Walperstyle

cometic work fine if your engine is good. aka, when the block and head get decked they should be mirrored.

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KA-T ORG-Function over Flush

two40guy

i just got back from measuring the actual cylinder bores and the measurments varied from 86.90 to 86.94 and the gasket bore was about 87.09 across the board sometimes more but i should just go with a different one?

hockeyrules

I dont' understand, everybody in this thread is telling you to get a new headgasket. You need a new headgasket, the OEM will not work.

two40guy

and they are.. everyone is telling me to get a 87mm headgasket.. its already over 87 mm.. fuck it. im gonna put it on anyways i measure the shit out of it yesterday and the measurements say it will work. the gasket bore is bigger than the cylinder walls themselves and its at the top of the stroke anyway if they are going above and beyond the gasket i got bigger problems.. im gonna give it a shot. if it blows oh well.. ill change it. if not, go me.

Pro ViZIon

Let us know how it works out.

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1990 Nissan 240SX w/KA24DE - New project
1984 Mazda RX-7 GSL-SE 13B

two40guy

Runs like a champ, boosting 22 lbs.. wheel spin through third. no overheating nothing. $35 OEM > $160 cosworth when you dont even need it.

Edwin562

22lbs on oem HG?? i have a strong feeling this aint right...

90hatchie

seriously lol
my oem one blew at 18psi on dyno
got an apexi and arp head studs and it hasnt given me a single issue since

two40guy

yep, haha i got arp studs with a an oem headgasket, which now that i think of it i should have just bought a top dollar one since i did a build on my sr anyway but cheaped out.. but ive been driving it around a while dailying it at about 15 pounds mind you. high boost is at 22 but i rarely ever use it. every once in a while though

but to clear things up i only ran 22lb once, hence the third gear wheel spin ever since ive been dailying on about 15lbs as i said above.

Edwin562

so what happen to"$35 OEM > $160 cosworth when you dont even need it." LMAO

never cheapen out on vital parts like this... yes you could of boost 22lbs once, but what if that was the last time u boosted 22lbs and the HG gave out... consider yourself lucky.... i blew my OEM HG at 18lbs as well. i was stupid, and now i spent more money.... build it right, the first time. nuff said...

Propaganda

Quick Question...

so if I'm ordering a headgasket for my 86.5 bore, I should order the 86 or 87 APEXi head gasket

Kouks

Order the 87x1.1 HG for stock compression the actual bore size of the HG will be 88mm and the HG will be stamped on the front 88 11. For the Bore size and thickness.

two40guy

yes. i would go with a hg it was meant for. i just ordered a top end kit mainly for the hg totally oblivious to the fact my bottom end was bored out.. and i kinda didnt really care if it blew i mean i would have had to change it but i want different cams and turbo set up so this set up realy only needs to last me till winter. then everything will be done correctly. i really only cheaped out and used the gasket i had because my car was apart for so long and i knew id be tearing back down again anyhow but again i would buy a nicer head gasket meant for your bore.