A good reference for you is the NASA Standard for Lifting Devices and Equipment. It 'should' be available via a search from nasa.gov website ... Look for " NASA-STD-8719.9 " Although this applies directly only to NASA and it's contractors, all of the OSHA, ANSI, ASME documents are...
In David Vizard's "Tuning the A-series Engines" book he gives a graphic representation: for an engine producing 100 hp for one minute, the air volume consumed is~ 150 cubic feet (works out to a 5.3 foot cube) and 27 cubic inches of fuel (3 inch cube). Use that to figure the velocity...