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The Pratt & Whitney R-4360 Wasp Major was a large radial piston aircraft engine designed and built during World War II. It was the last of the Wasp family and the culmination of its maker's piston engine technology, but the war was over before it could power airplanes into combat. It did, however, power the last generation of large piston-engined planes before the jet engine and turboprop took over.It was a four-row radial engine with 28 cylinders (seven per row); each row was slightly offset from the previous so that they formed a somewhat helical arrangement (as can be seen in the photograph) - this was to permit better cooling of the air-cooled engine. A mechanical supercharger geared at six times engine speed provided forced induction, while the propeller was geared at half engine speed so that the tips did not reach inefficient supersonic speeds.
Engine displacement was 4,360 cubic inches (71.4 litreThe litre (or liter in US) is a metric unit of volume. The litre is not an SI unit, but is "accepted for use with the International System". The symbol for the litre is the lowercase letter l or the uppercase letter L . A cursive or script small letter ls), hence the model designation. Initial models developed 3,000 hpThe horsepower hp is the name of several non-metric units of power. In scientific discourse the horsepower is rarely used due to the various definitions and the existence of an SI unit for power, the watt (W). However, the idea of horsepower persists as a (2240 kW), but the final models delivered 4,300 hp (3200 kW). Engines weighed 3,482 to 3,870 poundOfficially the pound is the name for at least three different units of mass: the pound (avoirdupois the troy pound the obsolete imperial pound There also exists an unofficial metric pound . While most standards bodies define the pound as a unit of mass, ms (1,600 to 1,800 kg), heavy but giving a power to weight ratio matched by very few engines.
The engine was commonly nicknamed the CorncobMaize Scientific classification Kingdom: Plantae Division: Magnoliophyta Class: Liliopsida Order: Poales Family: Poaceae Genus Zea Species Zea diploperennis ''Zea luxurians ''Zea mays ssp. huehuetenangensis ''Zea mays ssp. mays ''Zea mays ssp. mexicana '', since its multiple, staggered rows of cylinders made it resemble one.
Wasp Majors were produced between 1944Events World War II January January 4 The Battle of Monte Cassino begins. January 5 Murder of Danish playwright Kaj Munck January 17 British forces, in Italy, cross the Garigliano River. January 20 The Royal Air Force drops 2,300 tons of bombs on Berlin; and 1955; 18,697 were built. They were intended as a new powerplant for the Boeing B-29 Superfortress; Wasp Major-powered Superfortresses were eventually designated B-50. They also powered the Convair B-36 as well as a broad assortment of other aircraft:
