Im not sure if I worded corretly but how do you calculate the size of your intake ports. for example afr has 195cc how would you find out if you ported your own.

 

You can approximate based on what it flows, but if you want to know you'll just have to CC it like a combustion chamber with liquid.

FWIW, port volume isn't what's important, crossectional area is, so don't put too much into what your volume ends up at IMO.