Theoretical cfm (total for engine) = (rpm x cid)/3456
Q (flow rate in cfm) = V (velocity in ft/min) x A (area of the inlet/port/carb in sqft.)
piston velocity(V) = (stroke(in) x rpm)/6
Q=(6000x462)/3456=802.1cfm total thus div. by 8 for ea. cyl.=100.3ft^3/min
V=(4.21x6000)/6=4210ft/min
100.3ft^3/min=4210ft/min x A
A=0.0237ft^2=3.40in^2
3.40 is about 23% larger than the 2.6(2.596) the formula gives. They must be adding in all the other things in there some place or I've screwed up which wouldn't be the first time.
