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 designed to compete at lower power and was virtually a Wasp of reduced dimensions, as the details of construction were followed closely throughout. First certificated in January 1930 at 224 kW (300 hp), the Wasp Jr. was designed for light transports, trainers, sport aircraft, and helicopters. A number of models were made, most at 298 kW (400 hp) or higher power.

Powering a wide variety and large number of well known military and commercial aircraft such as the de Havilland Beaver and Lockheed Electra, the R-985 was one of the most successful reciprocating engines ever built in its power class. This model R-985-AN-14B powered the Avro Anson V twin engine aircraft, and McDonnell XHJH-1 and XHJD-1 (H-1) helicopters

Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Object Details

Date

Circa World War II

Country of Origin

United States of America

Type

PROPULSION-Reciprocating & Rotary

Manufacturer

Pratt & Whitney

Physical Description

Type: Radial, 9 cylinders, supercharged, air-cooled
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: 309.4 kg (682 lb)

Dimensions

Overall: 46 1/4 x 43 1/16in., 682lb. (117.5 x 109.4cm, 309.4kg)
Diameter 117.5 cm (46.25 in.), Length 109.4 cm (43.06 in.)

Inventory Number

A19771129000

Credit Line

Transferred from the Naval Aviation Museum

Data Source

National Air and Space Museum

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