Flow Benches and head porting

[zefarelly]

ANother Dark art . . . . but what experiences do people have ? how much have you got from an old nail ? or how little for that matter

regardless of total flow, I just flowed my race head which is nearly three years old now, it worlks well but I wanted to record what it did as a bench mark to start a new one and see if I can better it.

Inlet flowed 138 CFM with no valve in and 135 with the valve in, I believe its possible ( but rare) to gain flow with valves in, and I know If I could get the ports bigger I could flow more, but I think its respectable for the shape of the port and size of the engine and valve size etc ( 39.6 inlets)

the curve and figures almost exactly followed a Pug 106 rally head which has the same size valve