Pratt & Whitney R-1340 Wasp

The Pratt & Whitney R-1340 Wasp was a reciprocating engine widely used in American aircraft from the 1920s onward. It was the company's first engine, and the first of the famed Wasp family.^[1] 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 (146.05 mm). A total of 34,966 engines were produced.^[2]

Variants

• R-1340-7 — 450 hp (336 kW), 600 hp (447 kW)
• R-1340-8 — 425 hp (317 kW)
• R-1340-9 — 450 hp (336 kW), 525 hp (391 kW)
• R-1340-16 — 550 hp (410 kW)
• R-1340-17 — 525 hp (391 kW)
• R-1340-19 — 600 hp (447 kW)
• R-1340-19F — 600 hp (447 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 (447 kW)
• R-1340-48 — 600 hp (447 kW)
• R-1340-49 — 600 hp (447 kW)
• R-1340-AN1 — 550 hp (410 kW), 600 hp (447 kW)
• R-1340-AN2 — 550 hp (410 kW), 3:2 geared prop shaft
• R-1340-B — 450 hp (336 kW)
• R-1340-D — 500 hp (373 kW)
• R-1340-S1H1-G — 550 hp (410 kW), 600 (447 kW)
• R-1340-S3H1 — 600 hp (447 kW)

Applications

Specifications (R-1340-S3H1)

Data from ^[3]

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: 1,343.8 in³ (22.02 l)
• Length: 44.06 in (1,119 mm)
• Diameter: 51.38 in (1,305 mm)
• Dry weight: 805 lb (365 kg)

Components

• Valvetrain: Two overhead valves per cylinder
• Supercharger: Single-speed centrifugal type supercharger, 10:1 reduction
• Fuel system: Two-barrel Stromberg carburetor
• Fuel type: 80 octane rating gasoline
• Cooling system: Air-cooled

Performance

• Power output: 542 hp (404 kW) at 2,200 rpm at 5,000 ft (1,525 m)
• Specific power: 0.4 hp/in³ (18.36 kW/l)
• Compression ratio: 6.0:1
• Specific fuel consumption: 0.44 lb/(hp·h) (270 g/(kW·h))
• Oil consumption: 0.32 oz/(hp·h) (12 g/(kW·h))
• Power-to-weight ratio: 0.67 hp/lb (1.11 kW/kg)

See also

• Pratt & Whitney Wasp series
• Pratt & Whitney R-985 Wasp Junior
• Pratt & Whitney R-1535 Twin Wasp Junior
• Pratt & Whitney R-1830 Twin Wasp

References

Notes

Bibliography

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.
• Pratt & Whitney's R-1340 page