Your engine is an air pump.  For a 4 cylinder aircraft engine each revolution has 1 cylinder drawing in air, 1 compressing air, 1 firing and 1 exhausting combustion products.  Thus, 1 revolution consumes 1/4 x 360 cubic inches or 90 ci or .625 cubic feet. At 2700 rpm and WOT, that's 2700 x .675 cf or 1688 cfm.  Lbs/Hr depends on air density.

This is a bit nit picky, but I think your 4 cylinder engine probably draws two cylinders of air, 2 compressions, 2 combustions and 2 exhaust events per revolution rather than just one.

 

This annalysis draws me to a trivial question I can no longer rember the answer to. Back in the days of big lizards, when cars (fun ones anyway) were powered by engines exceeding 400 cubic inches and fed by carburators, the typical carburator size was 750 to 1050 cfm. (refering to street cars here) These engines turned twice the 2700 rpm in a typical aircraft power plant. Volumetric efficiency would reduce the actual flow rate slightly below the calculated value but not a whole lot. So why weren't the carburators rated about 10 times larger than they were?

 

Anyone remember the reason?

 

Rob