What size head gasket would I need?

[2000 legacy b4]

Have a EJ22 lying round with a 9:7:1 CR ratio and figure if I put my EJ208 heads on it with a thick HG I could get it to a more usable level of 9:0:1 that the GT-B\'s run, So if any of you know what size HG i\'ll need this will be greatly appreciated

[2000 legacy b4]

Looks like I can get 1.6mm upwards from STA parts, Would I need one for a EJ22 or a EJ20?

[funkytown]

you need to use the ej22 pistons, the NA ones are no good. Nor are the rods.

once you\'ve done that the dish shape in the piston changes and drops the compression heaps.

FWIW... i use a 1.6mm headgasket with the above turbo pistons and a phase 1 ej20k head (noting ej208 bowl shape is a touch different iirc) this nets about 8.4:1... just perfect.

also.. make sure you get a multi layer steel headgaset.. ALL the non turbo ones ARENT.

Also also.. if you\'re asking which HG you should be using (ej20 vs ej22) then you need to be doing more home work to understand whats going on.... p.s its the ej22 hg you need.

[2000 legacy b4]

I was going on the principle of "use the gasket to match the head" but I wont be swapping pistons / rods round this is just a temporary thing to get my car up and running so I can drive it to work haha

[funkytown]

no, match the cylinder bore it wont seal otherwise.

i dont see using that block will result in anything good as you describe it!!

[2000 legacy b4]

I see a guy on the NASIOC forums has used a $40 EJ22 N/A as a replacement for his blown EJ205 and once assembled it was around the 8:8:1 ratio and that ran for 4 months in his ownership and he has since sold the car and it\'s still going hard to this day apparently so I don\'t believe they are as week as people make them out to be.

[funkytown]

just saying.

[2000 legacy b4]

I imagine you know what your talking about, How ever in this instance I am going to go ahead with my plan so if you or any one else would know what thickness HG I should be using that would be ideal

[lachlan]

do it man . keen to see results .

you might have to do the full maths for your engine . as most people will use the other pistons etc . might have to cc your pistons and head etc . then find an online calc

[2000 legacy b4]

The way I see it is it\'s a good way to learn I mean every one says you can\'t boost N/A engines but half of them haven\'t done it Here\'s a fact, The EJ205 is no stronger or weaker than the EJ22E they both have cast pistons and the crank and rods are they same quality so there for I have no idea why this wont work!

[funkytown]

The head design on the na is different to turbo. U need to learn how to do some compression calcs.

Thay will tell you hg size.

However more than likely ul need to largest ypu can get being 1.6mm which means you just be working out just how high the cr remains.

[2000 legacy b4]

The Cometic one\'s go up to 3.56 mm but I have to wonder how reliable it would be having a gasket that thick :

[hijacka]

 2000 legacy b4 said:

The Cometic one\'s go up to 3.56 mm but I have to wonder how reliable it would be having a gasket that thick :

Why are you bothering thinking up a half arse headgasket and block idea? you will blow a beb before its next oil change or a ring land lol Get a decent short block

FWIW you \'\'must\'\' have true flat surfaces on both block and heads for a cometic gasket and studs they dont seal well..but if you suceed you might still struggle getting the intake manifold on with the added 3mm and dont forget to get some flange gaskets for the exhaust manifold or the extra 3 mm pull will cause the pipes to crack. Its a really bad idea this one lol hurts just thinking about it.. engine out engine in engine out engine in

[Koom]

Cam timing with 3.56mm gaskets would be interesting without adjustable pulleys.

If you could find what the head cc difference is, then you could do some backwards maths to give a ballpark figure for C/R.

[2000 legacy b4]

At a guess 2.1mm would work