Pratt & Whitney R-1340 Wasp

The Pratt & Whitney R-1340 Wasp is an aircraft engine of the reciprocating type that was widely used in American aircraft from the 1920s onward. It was the Pratt & Whitney aircraft company's first engine, and the first of the famed Wasp series. It was a single-row, nine-cylinder, air-cooled, radial design, and displaced 1,344 cubic inches (22 L); bore and stroke were both 5.75 in (146 mm). A total of 34,966 engines were produced.

As well as numerous types of fixed-wing aircraft, it was used to power helicopters, the Agusta-Bell AB.102 and the Sikorsky H-19, and a class of airship, the K-class blimp.

In 2016, it received designation as a Historic Engineering Landmark from the American Society of Mechanical Engineers.

Variants

Note: R for Radial and 1340 for 1340 cubic inch displacement.

R-1340-7: 450 hp (340 kW), 600 hp (450 kW)
R-1340-8: 425 hp (317 kW)
R-1340-9: 450 hp (340 kW), 525 hp (391 kW)
R-1340-16: 550 hp (410 kW)
R-1340-17: 525 hp (391 kW)
R-1340-19: 600 hp (450 kW)
R-1340-19F: 600 hp (450 kW)
R-1340-21G: 550 hp (410 kW)
R-1340-22: 550 hp (410 kW)
R-1340-23: 575 hp (429 kW)
R-1340-30: 550 hp (410 kW)
R-1340-31: 550 hp (410 kW)
R-1340-33: 600 hp (450 kW)
R-1340-48: 600 hp (450 kW)
R-1340-49: 600 hp (450 kW)
R-1340-AN1: 550 hp (410 kW), 600 hp (450 kW)
R-1340-AN2: 550 hp (410 kW), 3:2 geared prop shaft
R-1340-B: 450 hp (340 kW)
R-1340-D: 500 hp (370 kW)
R-1340-S1D1: 525 hp (391 kW)
R-1340-S1H1-G: 550 hp (410 kW), 600 hp (450 kW)
R-1340-S3H1: 600 hp (450 kW)
R-1340-T1D1: 520 hp (390 kW)

Applications

Engines on display

There are a Wasp A and three Wasp C's on display at the New England Air Museum, Bradley International Airport, Windsor Locks, CT.

Specifications (R-1340-S1H1-G)

Data from Jane's.

General characteristics

Type: Nine-cylinder single-row supercharged air-cooled radial engine
Bore: 5.75 in (146 mm)
Stroke: 5.75 in (146 mm)
Displacement: 1,344 cu in (22.02 L)
Length: 47.7 in (1,210 mm)
Diameter: 51.75 in (1,314 mm)
Dry weight: 930 lb (420 kg)

Components

Valvetrain: Two overhead valves per cylinder
Supercharger: Single-speed centrifugal type supercharger, 1:10 step-up
Fuel system: Two-barrel Stromberg carburetor
Fuel type: 91 octane rating gasoline
Cooling system: Air-cooled
Reduction gear: 3:2

Performance

Power output: 600 hp (450 kW) at 2,250 rpm at 6,200 ft (1,900 m)
Specific power: 0.45 hp/cu in (20.5 kW/L)
Compression ratio: 6:1
Power-to-weight ratio: 0.65 hp/lb (1.07 kW/kg)

References

Notes

Bibliography

Bridgman, Leonard. Jane's All the World's Aircraft 1945-46. Hammersmith, London: HarperCollinsPublishers (1994 reprint). ISBN 000 470831-8
Gunston, Bill. World Encyclopedia of Aero Engines: From the Pioneers to the Present Day. 5th edition, Stroud, UK: Sutton, 2006.ISBN 0-7509-4479-X
White, Graham. Allied Aircraft Piston Engines of World War II: History and Development of Frontline Aircraft Piston Engines Produced by Great Britain and the United States During World War II. Warrendale, Pennsylvania: SAE International, 1995. ISBN 1-56091-655-9

External links

"Index of Wasp & R-1340 Designated Engines", a scanned Pratt & Whitney reference document from 1956 detailing the different Wasp versions, their specifications, and the aircraft they were installed in.
"Radial Engines". Covington Aircraft. Retrieved October 26, 2019.
There is a "Pratt & Whitney 1340N Radial Engine" in use on a T-6 Texan at Pacific Warbirds, Oahu, HI

Pratt and Whitney R1340 Wasp, the Wasp that started it all r