33000

Updated: June 9, 2025

D = Diameter of fly-wheel and diameter of brake rope in feet. R = Revolutions of fly-wheel per minute. As 3.14 x D / 33000 will always remain the same for any given engine and gear, we may call that expression C; then the B.H.P. may be written

Walter C. Runciman - Gas and Oil Engines, Simply Explained: An Elementary Instruction Book for Amateurs and Engine Attendants