The Pratt & Whitney R-985 Wasp Junior is a nine-cylinder supercharged air-cooled radial engine. Over 39,000 of these engines were built from the 1930s to the 1950s. They powered numerous civil and military aircraft, small transports, utility aircraft, trainers, crop dusters and helicopters. It is one of the most reliable engines ever built. Major Applications: Beechcraft M17 and M18, de Havilland DHC-2 Beaver, Grunman G-21 Goose, Sikorsky H-5, Vought OS2U Kingfisher, Vultee BT-13 Valiant, Boeing Stearman M75.
| Engine Name | Pratt & Whitney R-985 |
|---|---|
| Manufactured by | Pratt & Whitney |
| Cylinder Configuration | Radial |
| Number of Cylinders | 9 |
| Displacement (cubic inches) | 985 |
| Bore (inches) | 5.187 |
| Stroke (inches) | 5.187 |
| Horsepower | 300-450 |
| Dry Weight (lb) | 640 |