thicker metal head gaskets
 

does anyone do one for the s12?

Fl EBAY.com or .com.au

Why do you want a thicker head gasket? What are you trying to achieve?

thicker gasket so can run more boost and will be stronger

The CA18ET is already 8:1.

It don't need to be any lower unless you want ridiculous boost.

i ran 32psi with the stock gasket.

Thicker gasket would upset the cam timing and also harm off boost performance and fuel economy imho

The cam would be advanced by less than a degree with even a 2mm gasket, so its not anything significant.

The off boost power would be reduced.

All of the above plus the fact that the boost depends on a fine balance between the comprssion ratio and the volume of air been induced into the cylinders. Yes the engine will take in more air, but what you gain you'll lose automatically becase the compression ratio will be far less. Sorry mate but you'll acheive nothing.

surely the increase in boost pressure that he's lookin to gain from doing this will over compensate the loss of compression!

but the ET is already a low compression engine, at 8:1 it's lower than a lot of turbo engines of the same era, newer turbo engines seem to be running a lot higher CR. the Audi/VW 1.8T is 9.5:1 for instance. IMO you don't need to go lower than 8:1.

The engine I'm building will have re-worked combustion chambers but I will skim the head to compensate

i thought the ET was 8.5:1:confused:

Nope its defo 8:1.

no, the DET it 8.5:1 the difference is almost entirely down to the larger chamber volume of the head, the pistons aren't dimensionally much different really

I skimmed 40thou of my head when I rebuilt so i reckon my CR is 8:5 - 9.0:1. No problems with detonation so far, i plan on using water injection if I hear any when I up the boost further.

I make that about 8.7:1

Yeah I make it 8.65:1 with 83mm pistons, and with 84mm pistons 8.85:1

do you know the exact chamber size? I had to reverse engineer the calculation to work that out.

I used reverse technology as well to provide a combustion size of 64.61cc.

the only reverse technology i use is to get off the driveway in the mornings:p

I'm using 0.5mm oversize pistons so I guess I have 8.7$:1, hope to gain more power with less boost pressure & lag....or it might blow a hole in a piston :confused:
Tested the mileage again and it's come out at 36mpg so i think it's helping the economy a bit