318 head porting for the average joe

consistent surface and shape.

polishing doesnt really gain much in cfm if the surface/shape is already consistent or 'smooth'...and some tests/theories imply it is easier for the mix/fuel to stick to the surface or 're liquify/re connect' to surrounding mix and lose velocity if contacting a mirror finished surface than if contacting smooth yet scratched/grained finished surface, let alone that the heaviest/lower velocity mix/flow is pushed outward...of corse there is always a compensation of rpm induced air speed.lol

boundry layer 101, good read.
http://www.desktop.aero/appliedaero/blayers/blayers.html