This is a Pratt & Whitney R-4360 Wasp Major aero engine, it has 28 cylinders in four radial rows with a displacement of 4,362.5 cubic inches (71.5 liters) and up to 4,300 bhp when in running condition.
The most famous aircraft powered by the R-4360 Wasp Major was the Hughes H-4 Hercules “Spruce Goose,” but over two dozen other aircraft used the design including the Boeing 377 Stratocruiser, Republic XF-12 Rainbow, and the Douglas C-74 Globemaster.
This is a Douglas C-124C Globemaster II, operated by the USAF, flying above the San Francisco Bay, with the Golden Gate Bridge and the Marin Headlands in the background. Image courtesy of the U.S. Air Force.
The Pratt & Whitney R-4360 Wasp Major
The Pratt & Whitney R-4360 Wasp Major would be the largest aviation piston engine ever mass-produced in the United States and the most powerful, with a maximum output of 4,300 bhp. These are records that seem unlikely to ever be broken due to the fact that not long after the development of the Wasp Major, most large aircraft switched over to turboprop or turbo jet engines.
The R-4360 Wasp Major was developed as part of the legendary Wasp series of Pratt & Whitney radial engines that had played such an important role in the United States war effort during the Second World War.
The model name R-4360 was chosen as it was a radial engine, “R,” with a displacement of 4,362.5 cubic inches, which was close enough to 4360. The engine had four rows of seven radially-positioned cylinders, each slightly offset resulting in a spiral-like pattern that earned it the nickname the “corncob.”
It was fitted with a mechanical supercharger, and one model used two hefty turbochargers in addition to the supercharger, becoming the most powerful variant. The engine was first run in 1944 and by the time it was ready to enter mass-production, the war was over.
Aircraft manufacturers still found use for it however, powering many of the period’s new passenger planes and the early precursors to the passenger jets of the modern day. A total of 18,697 examples of the Pratt & Whitney R-4360 Wasp Major would be made in total, though very few remain in operational aircraft today.
The R-4360 Wasp Major Engine Shown Here
The engine you see here is an original R-4360 Wasp Major Engine that is currently being offered for sale, with 100% of the proceeds going to the Air Combat Museum, a 501(c)(3) non-profit organization that is dedicated to preserving aviation history.
The engine itself is large, its size should be no surprise really as it has a displacement of 4,362.5 cubic inches (71.5 liters) with four rows of seven cylinders.
This engine was fitted to a Douglas C-124 Globemaster II in-period, and this is the aircraft that it would be removed from before being placed in to storage. It’s missing a number of components and it is not known when the engine last ran before the seller’s acquisition in 2021.
It’s now being offered for sale out of Springfield, Illinois in Bring a Trailer with removed components and a bill of sale. If you’d like to read more about it or register to bid you can visit the listing here.
Images courtesy of Bring a Trailer
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