Head Gasket Choice

[e30h26]

Hey folks,

I've tried using an online compression ratio calculator to work out what headgasket thickness I should be going for but its not making any sense (probably my stupidity). The basic spec of the build is as follows:

R32 Rb25DE with HKS2535/GTX3071 hybrid

GTR crank, rods and pistons

Nothing skimmed

I'm aiming for a massively responsive 450 on pump fuel. Can anyone advise what gasket thickness to go for or at least what CR I'd get with this set up on a standard head gasket so I can work it out?

Cheers.

[e30h26]

Forgot to add it'll be running a pair of HKS 264 8.5 lift cams also.

[SilverECR33]

CR wont change much, but your Quench will. id use a stocker. or a similar sized mls, the stocker is 0.9 i think. Ive got a multilayer rb25 metal MLS gasket for sale (used once), has it doesnt work on my 30/25 build. for $50 if you need it. it measures at 1.1 i think. pm me if ur interested.

Edited March 7, 2013 by SilverECR33

[e30h26]

Ive actually got a 1.1 headgasket already but wanted to be sure it would suit.

What effect will what ive done have on the squish/quench area?

[89CAL]

If you have an MLS gasket the block and head need a near perfect flat finish. If you haven't touched the mating.surfaces then it might not seal. If you have a normal gasket you might get away with it but I'd still like to finish the block surface if it was me

[e30h26]

The block and head have been checked and are flat from all angles that we tried. All the standard gasket material has been cleaned off so I'm happy it will seal. Im still trying to work out what CR i will end up with from either a 1.1mm or 1.5mm gasket though.

Can anyone tell me what the piston dome volume for a standard RB26 piston is? Ive also got a piston crown to deck measurement of 3.7mm, is this common?

Thanks for taking the time to respond lads.

[89CAL]

Just keep in mind if you use a MLS gasket it needs a smooth finish. Really smooth. 50CA from memory on the cometic. If you don't have an MLS ignore this