OEM Headgasket with boost?

[STOCK]

Im about to put my boosted motor back together with low comp forged pistons and wondering if OEM headgasket will be fine running 1 bar of boost? If not what gasket are you guys using?

[Slaz]

No problem at all, only need aftermarkets on biggers bore sizes. Oem gaskets are good.

[BRU51N]

would help if u used a thicker head gasket to help the low compression.

but stock ones should be ok

[saxman]

would help if u used a thicker head gasket to help the low compression.

but stock ones should be ok

NO NO NO NO NO NO NO NO NO NO NO NO NO


Stock headgasket to maintain quench are of the head, pistons to lower comp ratio if so desired. Changing the comp ratio via the headgasket is BAD BAD BAD.

He already said he has low comp forged pistons anyway, what would be the purpose of messing with it further.


Stock headgasket is great... I would be using some arp headstuds instead of oem head bolts though.

[DLO01]

Stock headgasket perfectly fine.

And exactly what Saxman said ^^^, Power is in the head. :thumbsup:

[STOCK]

OEM is sounding good for the moment, but my block has been bored to 81.5mm Doing some research, ive found that honda only offer pistons 0.25mm oversize so does that mean they dont sell 81.5mm headgaskets?

[yourfather]

you'll probably need an aftermarket one then.

[Slow96GSR]

Cometic ones come in about a dozen different thicknesses and about 6-8 different bores. It's what we use here, and I like them. The OEM one can still be used as long as the piston to head/valve clearance is still good. Use some clay, like a pinch, and ball it up. Place it on the piston, put the head on with or with out a gasket but don't use the head bolts, turn the crank once and pop the head off. Find the thickness of the clay and that will help you tell if you need a thicker gasket or one matched to your bore.

[Slow96GSR]

Just incase the piston(s) comes up too far. I would rather have the whole head push up then have to pull the pistons and recoat any coated parts. If you don't have coated parts I guess it wouldn't matter but I haven't done a motor in a while without at least coating the pistons. Also I know some people that just don't now when to stop turning and end up breaking something because the pistons hit the head.

[Slow96GSR]

It was just so he could see if he had the piston to head clearance to run a stock gasket. If the piston came up too much he could smash the gasket between the pistons and head. This would end up hurting things, or making no difference. Who knows.

[spardikis]

so... with the head not bolted down and just placed on the block - how are you suposed to do the test??

will the head stay located on the studds? and when using head 'bolts' do you just do the bolt up finger tight or something to do the test??

[xsiv]

you will be sweet

[ProECU]

hey maybe...NOT

[Slow96GSR]

so... with the head not bolted down and just placed on the block - how are you suposed to do the test??

will the head stay located on the studds? and when using head 'bolts' do you just do the bolt up finger tight or something to do the test??

Sorry to take so long answering, I missed this post!

1: Take about a ball of clay about 1/4"-1/2" in diameter and place it in the center of the piston. Try not to leave as the clay could dry. Also don't use the clay if it is sticky and falls apart as you want to try and keep it as one piece for an accurate measurement.

2: Make sure the piston in at least halfway down the cylinder before you put the head on. You can put two pieces on and turn the crank half way around for two pistons and then repeat for the other two, inside then outside or other way around.

3A: If you have studs the head will only move up and down not side-to-side. Place the nuts on just enough to stay on.

3B: If you have bolts put them in only enough to grip, like 1/4"-1/2" into the block.

4: If when you rotate the crank you feel and pressure like it doesn't want to spin STOP and loosen the bolts/nuts. You don't want to hurt anything.

5: Pull the head off and measure the thickness of the clay. If the head moved up a lot then it means you do not have enough clearance or the clay is too hard/dry. Find new clay or add water if it is water based clay and retest.

If you have 1/8”-1/4" or more, as the head might have moved up a little, you can go ahead and re-ball the clay and torque the head on. This will let you know the true clearance. The first test was only to make sure you were not going to have piston to head contact. Just remember if it stops turning freely, STOP! You will need to check the manual to see what the clearance is for your motor. Good luck and have fun! Try not to let the kids play with the clay too much as it dries it out. This also applies to you!!