Originally posted by wire2
Actually, it would be half of those numbers. There's 1 intake stroke for 2 crank revolutions, (4 stroke), so about 150 CFM.
I believe FunkRider is actually correct:
At 6500 RPM, there are 3250 intake strokes per minute
So, 3250*3.2L=10,400 liters/minute
This converts to 367 CFM
Like FunkRider said, that doesn't account for volumetric efficiency (the ratio of air mass actually drawn into a cylinder to the mass it would hold at atmospheric pressure). If someone can privide dimensions for intake valve lift, diameter, etc, we could calculate the Mach index for the valves and see how choked the flow is. I would guess, as did FunkRider, that the volumetric efficiency is actually around 80% (or possibly higher, if there are 2 intake valves), which would indeed make it closer to 295 CFM
If you design for around, say 330 CFM (90% vol eff), you might be a little on the conservative side, but that's a good thing in this case.