Pratt & Whitney R-4360 Wasp Major

The Pratt & Whitney R-4360 Wasp Major is an American 28-cylinder four-row radial piston aircraft engine designed and built during World War II. At , it is the largest-displacement aviation piston engine to be mass-produced in the United States, and at the most powerful. The prototype first ran on 28 April 1941,

The engine was a technological challenge and the first product from Pratt and Whitney's new plant near Kansas City, Missouri. The four-row configuration had severe thermal problems that decreased reliability, with an intensive maintenance regime involving frequent replacement of cylinders required. Large cooling flaps were required, which decreased aerodynamic efficiency, putting extra demands on engine power when cooling needs were greatest. Owing in large part to the maintenance requirements of the R-4360, all airplanes equipped with it were costly to operate and suffered decreased availability. Its commercial application in the Boeing Stratocruiser was unprofitable without government subsidy. Abandonment of the Stratocruiser was almost immediate when jet aircraft became available, while aircraft with smaller powerplants such as the Lockheed Constellation and Douglas DC-6 remained in service well into the jet era.

Engine displacement was , hence the model designation. Initial models developed , and later models . One model that used two large turbochargers in addition to the supercharger delivered . Engines weighed , giving a power-to-weight ratio of .

thumb|Sectioned R-4360 Wasp Major

Wasp Majors were produced between 1944 and 1955; 18,697 were built.

A derivative engine, the Pratt & Whitney R-2180-E Twin Wasp E, was essentially the R-4360 "cut in half". It had two rows of seven cylinders each, and was used on the postwar Saab 90 Scandia airliner.

Applications

Engines on display

thumbnail|R-4360 cutaway

thumb|R-4360-4 on display at the [[Air Zoo]]

thumb|R-4360 on display at [[Museum of Aviation (Warner Robins)|Museum of Aviation, Robins AFB]]

thumb|R-4360 on display at the [[National Museum of the United States Air Force in Dayton, Ohio]]

An R-4360 is on display at the Mid America Museum of Aviation and Transportation in Sioux City, Iowa.
An R-4360 is on display at the Museum of Flight in Seattle, Washington.
An R-4360 is on display at the Heritage Flight Museum in Burlington, Washington.
An R-4360 is on display at the New England Air Museum, in Windsor Locks, Connecticut.
An R-4360-59B is on display at the Combat Air Museum in Topeka, Kansas.
An R-4360 cutaway is on display at the Air Victory Museum in Lumberton, New Jersey.
An R-4360-4 cutaway is on display at the Air Zoo in Kalamazoo, Michigan.
An R-4360-59B cutaway is on display at the Florida Air Museum in Lakeland, Florida.
Two R-4360s are on display at the National Museum of the United States Air Force in Dayton, Ohio.
An operational R-4360 is on display at the Penngrove Power and Implement Museum in Penngrove, California.
An operational R-4360 is on display at Nieman's Harley Rentals in St Helena, California

Pratt & Whitney R-4360 Wasp Major

Applications

Engines on display

Specifications (R-4360-51VDT)

See also

References

Notes

Bibliography

External links