This is a Pratt & Whitney R-2800 “Double Wasp” radial engine, it has a displacement of 46 liters and in full running condition it’s capable of 2,200+ bhp – not bad given the fact that the design is 87 years old.
The Pratt & Whitney R-2800 is an aircraft engine that was used extensively throughout World War II, it powered many of the most iconic American aircraft of the conflict including the Douglas A-26 Invader, Republic P-47 Thunderbolt, Vought F4U Corsair, Grumman F8F Bearcat, Republic P-47 Thunderbolt, and many others.
Above Video: This is a full-length documentary about the Vought F-4U Corsair, one of the most famous and consequential aircraft to be powered by the Pratt & Whitney R-2800 Double Wasp.
The Pratt & Whitney R-2800 Double Wasp
The Pratt & Whitney R-2800 Double Wasp was America’s first 18-cylinder radial engine. It was developed in the mid-1930s, it first ran in 1937, and it was first fitted to an aircraft and flown in 1939. Strategically, the R-2800 Double Wasp would be one of the most important American-developed fighter aircraft engines of the war and it was produced in vast numbers – with over 125,000 made in total.
The R-2800 consists of two rows of nine cylinders each sharing a common crankcase. The engine has dual ignition systems, a total displacement of 2,800 cubic inches (46 liters), two valves per cylinder, and it was developed into over 100 variants including naturally-aspirated, supercharged, turbocharged, turbo-supercharged, and some later versions also had water injection systems which further increased power to as much as 2,800 bhp.
Given the compact dimensions of the engine, and the fact that it was air-cooled, much work was done to ensure it would remain within an ideal operating temperature window. Early prototypes were prone to overheating, and it was realized that the size and spacing of the cooling fins was insufficient.
New cylinder heads were developed made from solid aluminum alloy, these then had cooling fins cut into them with a machine that was developed specifically for the task. It consisted of multiple circular cutting blades all spaced equidistantly, so they could cut compact cooling fins into each cylinder head in a single motion, helping to accelerate production.
The Pratt & Whitney R-2800 Double Wasp would power a remarkable array of aircraft including fighters, medium-duty bombers, helicopters, and passenger aircraft. Some of the most famous include the Vought F4U Corsair, Northrop P-61 Black Widow, Lockheed XC-69E Constellation, Grumman F8F Bearcat, Douglas A-26 Invader, Douglas DC-6, and many others.
Many examples of the Double Wasp remain in operational condition today, most in warbirds or museum pieces but there are a few firefighting water bombers powered by the engine as well.
The Pratt & Whitney R-2800 Double Wasp Shown Here
The engine you see here is a Pratt & Whitney R-2800 Double Wasp, it’s one of the -75 variants meaning it has a built-in supercharger, and in full operational condition it will be capable of producing 2,200 bhp.
The R-2800 Double Wasp has two rows of nine cylinders, for 18 cylinders in total and a displacement of 2,800 cubic inches or 46 liters.
As it sits today, the engine hasn’t been run for years and its history before its current ownership is unknown. This means the engine will need a full rebuild before its run, and if the new owner intends to use it in an aircraft it will need to be rebuilt back to zero-hour condition.
If you’d like to read more about this unusual WWII-era aero engine or place a bid you can visit the listing here. It’s being offered for sale on Bring a Trailer out of Ontario, Canada with no reserve and it comes with a bill of sale.
Images courtesy of Bring a Trailer
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