I agree it's not the valve throat controlling the flow. As mentioned above, with the standard valves fitted that area is a fair bit larger than optimum. The main reason for increasing valve size was to optimize the throat/valve area ratio.
It has been achieved, and the measured results come from a Superflow bench. The figures are not BPF - they are valve in at 10.8mm lift.
The unmodified head flows correlate 1:1 with your figures, the modified head/standard valve flows correlate 1:1 with your own figures, so there is no reason to doubt the flows figures measured by the bench with the larger inlet valves, with the controlling sections of the ports modified to match. I am sure you could achieve the same. Why not give it a try?
Last edited by group5lancia; 01/06/2010 13:17.