By
1930, Pratt & Whitney's Wasp was
producing 500 hp (372 kW) and the company decided to develop the Wasp
Junior to compete in the 300 - 400 hp (220 - 300 kW) market.
The first R-985 produced 300 hp and flew in 1930. By the end of World War II, improved R-985s produced
450 hp and were used in thousands of military and civilian aircraft.
The R-985 was in production from 1930 through 1953. Over 39,000
were produced.
