Ok guys, i'm swapping a h22 head onto a H23 block, but i want to sleeve it, I want to max it out. So whats the max mm i can sleeve the block to. And also what size Valves would i have to use when maxing out the size on the H23 block?

I don't know the what the sizes are on the valves. Are the Exhaust valves smaller than the intake valves?

I know the stock bore on the H23 Block is 87mm, so how big can i go? lol

 

I figured it out the Intake valves are 35mm and the exhaust valves are 30mm

 

I would just call a sleeve manufacturer like Darton, (because they have quality stuff) and ask them what their biggest is for the H23....or go to their website. Then you can start looking for what pistons to use, etc.
Do you really need to sleeve it? How much HP are you looking at pushing?

 

What size to bore H-23? The sleeve bore size I would go with is 88mm and a maximum of 91mm can be done but I would stay at 88mm.
If you plan on boosting over 20lbs then 89.5 is the largest you can go with the ''O'' ring groove.
KEEP CALM and CARRY ON with G.E.

 

ERL in Indiana suggests a max of 90mm.