Originally Posted by PEI330Ci

I agree, it's always good to have someone to bounce numbers off of.

I've got my own spreadsheets, but I also use Larry Meaux's software.

Here's the finished piston design, which is even more extreme than you thought:







Valve relief was for really big cams....300/296 custom design from Schrick:



You don't want to oversize the exhaust valve....unless you've got a heat issue and need the extra surface area to dissipate heat back into the head. I had a head ported for 30.5mm and another head ported with 31.5mm valves, and the smaller valve flowed a little bit more up top.