i'm in the middle of putting a 1.8 ztec bottom end in my mk2 xr2 and i was going to use the cvh head , but the standard piston's have a dome in the top where as ztec ones are flat .
this will lower the compresion of the engine, will it lower it to much to keep the n/a or will it be ok ???
if i need different pistons to bring the compresion back up to n/a levels where can i get them from ???
thanks

 

you might be better dummy building it and calculating the CR

Is the block longer stroke or bigger bore to increase capacity? this all will have an effect on the comp ratio from what i guess, probably more so than just the pistons!

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