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10.5-11:1 pistons for B18B??

1438 Views 7 Replies 4 Participants Last post by  skibbs
Hey guys,

I'm toying with the idea of getting maybe US GS-R or ITR or JDM GS-R pistons to raise compression to somewhere between 10.5:1 and 11:1. Which do you think I should get?

Also, I had a few questions about actually getting the things into my engine:

1) Where should I buy the pistons from?

2) I know ITR pistons require the rods to be milled 1mm. Do you have to do this for GS-R pistons as well?

3) How much would it cost to slap pistons in, including honing the cylinder walls (I have 44k miles if it matters).

4) Would this be reliable for a long time? We're talking several years here....

5) Where should I get all this work done? I don't want some Camaro-lovin' hick to [email protected] up my car.

and finally 6) If I did go through with this, you think I would need an aftermarket clutch? Mine's not very worn, but I already have probably around 150whp+ once I get the header and cat put on and the thing dyno-tuned. Upping compression around 1.5 points would bump power quite a bit.

Thanks a bunch! As much knowledge as possible would be appreciated.
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check out this link and play around with it until u find the numbers ur looking or aiming for:

now, let's see if we can answer ur questions.

1. u can get the OEM pistons from ur honda/acura dealer, ebay, or some other performance shop that can acquire them. (DON'T get used ones)

2. for ur b18b rods, yes u will have to mill the small end of the rod 1 mm on each side -- so u can fit the VTEC pistons in (GSR, ITR, B16)

3. ask around in ur area on how much the machine shops will charge to slap pistons in and to hone the cylinder walls. u might have to bring the block in first so the machinist can assess how much they're going to hone ur cylinders to. from there they can tell u if u need to order pistons in 0.25 over or something.

4. the dependability will depend on how the work is done and where u take it to. so do ur research regarding the machine shops in ur area (or somewhere else if ur going to ship it) and ask questions pertaining to ur engine plans.

5. domestic machine shops are not all that bad. as long as u visit their facility, check out how clean it is, how preofessional looking and/or "sounding" they are, and all that stuff. i actually had my b20/vtec done by a machine shop who works with domestic engines too. and the owner owns and built a full blown race engine sponsored by summit racing.

6. u can get an aftermarket clutch later. ur going to be fine with ur stock for now while ur breaking-in ur new engine. it'll give u some time to save up for a nice clutch setup too.

well, i hope i answered all ur questions. just try not to rush things when doing ur build-up. it might end up in cutting corners and stuff like that -- which might lead to a project gone bad.
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Thanks, that was very useful. I don't know if I'm willing to spend/research that much right now, maybe next summer or something. I'm just entering college, and like you said, I don't want to rush things.

In the meantime, maybe I could just slap in a good single-layer head gasket for a little bump in compression, what do you think? How hard is it to pull the head and do this? I helped out with my cam install, is pulling the head much more than that? What would be a good head gasket to get? Thanks for the CR Calculator again, BTW, I had it bookmarked but they changed the z to an s in bojangs. According to this, a 1-layer (diff. kinds vary in thickness of course) would give me 0.3-0.4 point increase. This way I could get a nice little power bump while not having to really worry about internals or spend a lot of money, at least until later.

If I got the thinner head gasket, would it alter my cam timing? I know I've heard something before about milled heads messing with your cam timing, I was wondering if it was the same effect as with a thinner head gasket.

Thanks a ton for your help.
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taking the head off is not that hard -- as long as u follow the procedures set by ur service manual or helms manual. make sure that u remember where the hoses go, and the same goes with the sensors. put a sticky on them or colored tape or something so u won't get mixed up when putting the head back on.

a single layer headgasket won't alter ur timing. milling the head might compromise ur piston-to-valve clearances if too much is taken off. milling should only be done just to keep the head level and that should be it. the stock head was designed so that u can get away with some margin of error if u plan on using a single layer gasket and so forth. so milling the head to gain more compression is a no-no -- at least to me, that is.
Cool, thanks! I dunno, maybe I'll do the pistons next summer or something when I have more money and knowledge. And just doing the head gasket doesn't seem like it's really worth it for the minimal gains. Oh well, I guess I do another mod. Thanks a lot for your help though, it was very useful. :)
Don't they make aftermarket pistons out there that are direct fit? I thought JE made some.
Yeah, but they're more expensive than Honda pistons generally.
Cometic MLS head gaskets for NA apps... PM me if you want em White98LS, I can get em ass cheap :D Just got some of my parts! I'll let you know how it turns out once I rebuild my B18B in the next 2-3 weeks. I think I'm going to go with the Toyota dude that I mentioned to you. Mark still hasn't called me back on shaving my emblems, I think he forgot :rolleyes: hehe I'll call him again this week.
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