there was another type on ebay, same thing claiming 200CFM IIRC.
right,
take F7P: 1764cc
say it runs @ 8000 RPM
there r 2 induction strokes/rev, so with 1 revolution there will be 2x441 (1764/4) = 882cc
therefore in 1min: 882x8000 = 7056000cc will be induced
now, 1ft = 30.48cm, so 1 cubic foot=91.44cc
therefore 7056000 cc/min = 77165.4 CFM
this is assuming 100% VE, but still.....
ill let u decide whether it works!!!