Is it necessary to match the combustion chamber diameter to the bore of each cylinder? If so how precise does it have to be? If not, how much of a difference can there be between the two diameters? TIA.

 

It is not needed to change the CC at all. Deschrouding basically lowers your compression.

 

thats right.boring the cylinder will create less turbulence when the air/fuel pass theru the valves.

 

Great. I just exhaled a $2k sigh of relief.

 

Why do you say that? Deschrouding a head doesn't cost much at all.

 

I only have one car, so if I sent the head out for work I'd have to do it all at once, meaning head work, cc work, valvetrain, etc. My boss nearly comes to tears when I ask for a weekend off. I think he'd have a stroke if I asked for a week off. As it is now I can swap the motor and reinstall the head onto the new block, without missing work by wrenching during the week after classes.

 

how much compression lost would result from deshrouding a head for 85mm bore