FWIW here is a formula I use in my excel spreadsheet that calculates airflow requirements based on size, RPM for peak power, VE. It came from Larry Meaux on the speedtalk forum. He also posted lots of other useful engune math formulas.
Flow = ( CID * RPM * .000978474 * Ve% ) / ( Cylinders * 127.5 )
where
Cylinders = Number of Cylinders
127.5 % Ve = theoretical VE possible at .60 Mach or 699-700 fps
Note=> that 127.5 theoretical Ve is also dependent upon piston speed
and that at lower piston speeds even if there is .60 Mach, its not possible to achieve 127.5 %, but much less
This is not a absolute but has worked well for me over the years. It does not care about low lift vs high lift flow or velocity but just tells you how much airflow is required thru the intake system, aircleaner thru valve to fill a cylinder of X size at a VE of X% at XRPM.