max tolerance for decking head?

[zlyricist]

it looks like my build will most likely be with f2t pistons, and a very low compression, 7.2-7.3:1. i want to deck the head some to bring the compression back up to mid 7s if at all possible. what is the max tolerance? i dont have a manual

and since im decking the head, should i also get the block decked? i plan on using a MLS gasket

[mx-3_4evr]

I would deck the block instead. Gives the head another chance incase it warps in the future

[chief tool]

I would do the block also, you couldnt take enough off the head to make a difference to the C/R I think the WSM doesnt recommend any machining of the head...the warp tolerance is 0.15mm say you machine it 0.5mm, thats as much as I'd do, thats bugger all difference to the C/R.

why do you have to use F2T pistons, why not F2 ones ? Or..... use FE 8 valve rods and use any of the pistons available for the 8 valve and 12 valve FE motors.

If you do that you can get flat tops from an 8 valve F8 which should mean a C/R about the same as stock.

excuse me if I missed the point....I didnt fully read the other thread

[fredio54]

Why use a non-oem head gasket? Bad idea IMO.

As for decking, you should definitely machine both the head and the block, but both in as minor a way as possible. What you are looking for is surface finish, not comp ratio change. Use the f2 pistons man, why f2t? Esp with e85 available, you'd be best off on kia pistons and that rather than going that silly low. You could have issues starting the bastard at your altitude and that ratio.

Fred.

[zlyricist]

well i wanted to run high boost on pump gas for a while, in time for me to boost my 2g ze.......and e85 is a huge pain for a daily driver. reason i wanted to use f2t pistons is because i got a set on the cheap (30 bucks) but i guess i really should spend the extra few bucks and get f2 pistons, and deck everything as little as possible. ill probably just cruise it on pump gas, n/a for a while. i just hate driving a slow car! haha