Pratt & Whitney Wasp Jr. R-985-AN-1, Radial 9 Engine

Type: Reciprocating, 9 cylinders, radial, air cooled, geared supercharger

Power rating: 336 kW (450 hp) at 2,300 rpm

Displacement: 16.1 L (985 cu in.)

Bore and Stroke: 132 mm (5.2 in.) x 132 mm (5.2 in.)

Weight: 306 kg (674 lb)

The Wasp Jr. R-985 was the third engine type designed by Pratt & Whitney Aircraft, following the Wasp R-1340 and Hornet R-1690, all of which were nine-cylinder engines. The Wasp Jr. was virtually a Wasp of reduced dimensions, as the details of construction were followed closely throughout. The Wasp Jr., originally rated at 224 kW (300 hp), was first type certificated in January 1930. It was designed for light transports, trainers, sport aircraft, and helicopters. A number of R-985 models were made, most at 298 kW (400 hp) or more power. It powered a wide variety of military and commercial aircraft, making it one of the most successful reciprocating engines ever built in its power class.

This artifact was a spare engine for the Bell XV-3 convertiplane which had some flight time. The R-985-AN-1 also powered the: Platt-LePage XR-1A helicopter; Fletcher YCQ-1 target control; Beech CQ-3 target control; Beech T-7/A trainer; and Beech T-7B/C trainer.