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I have an RB26 just about to undergo a rebuild. Nothing spectacular the number will be about 500rwhp on 20lb's.

Obviously it needs a head gasket of some sort. Are there any preferred styles/brands etc.

What size should the gasket be relative to the pistons? Does (say) an 86.5mm piston need a certain sized gasket that may be different for an 87mm piston?

Lastly there are a number of different thicknesses available. Is the 1.2mm thickness essentially the "stock" size.

EG 11044-RRR46 Nismo Metal Head Gasket

Edited by djr81
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yeah the thing is if you are looking at metal gaskets like tomei etc 1.2mm will actually be a tiny bit thicker than the oem gasket which has a fair bit of crush in it. from memory tomei make a 1.1 and 1.0mm but 1.2mm is the 'default' choice for most builds. the tomei gasket is a good thing and if your doing a rebuild just buy the full tomei gasket kit. it comes with head gasket and exhaust and intake gasket all of which are good quality and includes the oil feed restrictor too. so yeah you'll need the 87mm gasket kit, in whatever thickness you like.

Thanks Baron. They do a 1.2mm (1.0 is discontinued) in 87mm.

There is a metal super Grommet one, presumably the other type is a Wallace?

age spot showing!!! lol. yes avoid the wallace, go for the grommet. it's true factory head gasket with or without hylomar is fine too but if you want a bit of headroom to run higher boost etc you are better off with a tomei or some other MLS gasket.

The cometic mls gasket kits are extremely good value out of the US at the moment, you can pick up a complete top and bottom kit (with head gasket, valve stem seals etc etc) for roughly the cost of a jap HG. It's fairly obvious but select the thickness based on the cr you want to run.

I am current running 22psi on a relatively high comp rb30dett motor.

Standard head gasket. All I did was ARP head studs.

Been like that now for 12+ months. I did start off with a cometic which leaked, pulled it off, went genuine and was all good, made no changes to block/head or torque procedure (torque values where obviously different between the two). The problem with the cometic is they have a rediculously stupid RA, so the block/head has to be near absolutely perfect or you can get water/oil contamination like I did.

Had a tomei in a build before that, and mate went tomei, very good. I would recommed that over the cometic anyday.

You get what you pay for. Obviously some have had success with them so take it with a grain of salt.

Edited by James_03

agree^

I have heard similar stories on the cometic units from friends. I have never used them. Always used tomei or oem. Never had any issues even when re using the tomei gasket several times. Quick spray of permetex and back in she goes :)

Ive reused my old cometic without any dramas. Just some hylomar and it worked with no leaks at all. Same goes with the acl mls gaskets weve used on the race car, many times over with just hylomar and no issues.

Any mls headgasket needs a very good finish to get a good seal. I guess the viton coating on some gaskets is better then others or some machineshops dont get the right ra needed. The smoother the better!

+1 for tomei I opted to go for it over the stock and no probelms so far, didnt machine the head or block but they were within the tolerance that the manual states. But yeah Tomei if you can afford the extra coin or if really struggling then go stock.

strange. I've used and reused Cometic gaskets on the race car for years without any issues.

without any issues? dundan? lol. maybe without any 'headgasket' issues but it's been in and out plenty of times!

sure, but I've never had a head gasket problem, even when I've reused them (which I have plenty of times), even on heads and blocks that have not been machined flat.

Also...its worth saying you hear very few problems with head gaskets on RBs, almost none in fact.

yeah it's true. not many head gasket issues in general but part of that is most people leaning on their 26s have already blown them for one reason or another and include a MLS or other good gasket of some kind in the rebuild. not many people running 25psi etc on the standard head gasket though that's not to say it'd necessarily be a problem. it's just that we have plenty of other weak points to deal with first! anyway, everyone has their own favourites. I've seen lots of good results with the tomei gaskets and have used a few myself and seen them re-used too. plus the kit the sell is quite good value as it includes all the main bits you need.

yeah it's true. not many head gasket issues in general but part of that is most people leaning on their 26s have already blown them for one reason or another and include a MLS or other good gasket of some kind in the rebuild. not many people running 25psi etc on the standard head gasket though that's not to say it'd necessarily be a problem. it's just that we have plenty of other weak points to deal with first! anyway, everyone has their own favourites. I've seen lots of good results with the tomei gaskets and have used a few myself and seen them re-used too. plus the kit the sell is quite good value as it includes all the main bits you need.

Cheers. I think I will end up with a MLS of some description. Maybe ACL or Tomei.

Here are some other bits I prepared earlier which should fix a couple of weaknesses. :)

post-5134-0-49695800-1297742457_thumb.jpg

post-5134-0-76330500-1297742471_thumb.jpg

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