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 successive 
rows of cylinders. 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 in³ (71.4 L), hence the model designation. Initial models developed 
3,000 hp (2240 kW), but the final models delivered 4,300 hp (3200 kW). Engines weighed 3,482 to 3,870 lb, 
heavy but giving a power to weight ratio matched by very few engines. 56 sparkplugs to change and 7 
magnetos to set on a tuneup!  (2 plugs per cylinder.)
The engine was commonly nicknamed the Corncob, since its multiple, staggered rows of cylinders made it 
resemble one. Wasp Majors were produced between 1944 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:

Boeing B-29
TWA Super G Constellation
Sud-Est SE-2010 Armagnac 
Boeing XB-44 Superfortress 
Boeing B-50 Superfortress 
Boeing 377 Stratocruiser 
Boeing C-97 Stratofreighter 
Boeing F8B 
Aero Spacelines, Inc. Pregnant Guppy and Mini Guppy 
Convair B-36 
Convair XC-99 
Convair A-41 
Curtiss XBTC-2 
Douglas TB2D Skypirate 
Douglas C-74 Globemaster 
Douglas C-124 Globemaster II 
Fairchild C-119 Flying Boxcar 
Fairchild C-120 Packplane 
Goodyear F2G 
Hughes XF-11 
Hughes H-4 Hercules ("Spruce Goose") 
Lockheed Constitution 
Martin AM Mauler 
Martin JRM Mars 
Martin P4M Mercator 
Northrop B-35 
Republic XP-72 
Republic XF-12 Rainbow