The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is called a "star engine" in some other languages.
The Taurus is a British 14-cylinder two-row radial aircraft engine, produced by the Bristol Engine Company starting in 1936. The Taurus was developed by adding cylinders to the existing single-row Aquila design and transforming it into a twin-row radial engine, creating a powerplant that produced just over 1,000 horsepower (750 kW) with very low weight.
The Centaurus was the final development of the Bristol Engine Company's series of sleeve valve radial aircraft engines. The Centaurus is an 18-cylinder, two-row design that eventually delivered over 3,000 hp (2,200 kW). The engine was introduced into service late in the Second World War and was one of the most powerful aircraft piston engines to see service.
The Wright R-3350 Duplex-Cyclone is an American twin-row, supercharged, air-cooled, radial aircraft engine with 18 cylinders displacing nearly 3,350 cubic inches (54.9 L). Power ranged from 2,200 to over 3,700 hp, depending on the model. Developed before World War II, the R-3350's design required a long time to mature before finally being used to power the Boeing B-29 Superfortress. After the war, the engine had matured sufficiently to become a major civilian airliner design, notably in its turbo-compound forms, and was used in the Lockheed L-1049 Super Constellation airliners into the 1990s. The engine is commonly used on Hawker Sea Fury and Grumman F8F Bearcat Unlimited Class Racers at the Reno Air Races. Its main rival was the 4,360 in3 (71.4 L), 4,300 hp (3,200 kW) Pratt & Whitney R-4360 Wasp Major, first run some seven years after the Duplex-Cyclone's beginnings.
The Lycoming XR-7755 was the largest piston aircraft engine ever built in the United States, with 36 cylinders totaling about 7,750 in³ (127 L) of displacement and a power output of 5,000 horsepower (3,700 kilowatts). It was originally intended to be used in the "European bomber" that eventually emerged as the Convair B-36. Only two examples were built before the project was terminated in 1946.
The Armstrong Siddeley Mongoose is a British five-cylinder radial aero engine produced by Armstrong Siddeley. Developed in the mid-1920s it was used in the Hawker Tomtit trainer and Parnall Peto seaplane amongst others. With a displacement of 540 cubic inches (9 litres) the Mongoose had a maximum power output of 155 horsepower (115 kilowatts).
The Warner Scarab is an American seven-cylinder radial aircraft engine, that was manufactured by the Warner Aircraft Corporation of Detroit, Michigan in 1928 through to the early 1940s. In military service the engine was designated R-420.
The LeBlond radial engines, later produced under the name Ken-Royce, were a family of 3-cylinder, 5-cylinder and 7-cylinder, air-cooled radial engines for aircraft, built in the 1930s by the LeBlond Aircraft Engine Corporation until the operation was sold to Rearwin Airplanes in 1937 and renamed Ken-Royce Engines.
The Nakajima Hikari was a nine-cylinder, air-cooled, radial aircraft engine developed in Japan for Navy use during World War II by the Nakajima Aircraft Company. It was a development of the Nakajima Kotobuki and Wright Cyclone. In Army use it was known as the Ha20.
The Jacobs R-755 is a seven-cylinder, air-cooled, radial engine for aircraft manufactured in the United States by the Jacobs Aircraft Engine Company.
The Lawrance J-1 was an engine developed by Charles Lanier Lawrance and used in American aircraft in the early 1920s. It was a nine-cylinder, air-cooled radial design.
The Wright R-2160 Tornado was an experimental 42-cylinder, 7-cylinder per row, 6-row liquid-cooled inline radial aircraft engine. It was proposed in 1940 with 2,350 hp (1,752 kW) for experimental aircraft such as the Lockheed XP-58 Chain Lightning, Vultee XP-68 Tornado, and the Republic XP-69.
The Kinner R-5 is an American five cylinder radial engine for light general and sport aircraft of the 1930s.
The Wright R-790 Whirlwind was a series of nine-cylinder air-cooled radial aircraft engines built by Wright Aeronautical Corporation, with a total displacement of about 790 cubic inches (12.9 L) and around 200 horsepower (150 kW). These engines were the earliest members of the Wright Whirlwind engine family.
The Alvis Pelides was an unflown British air-cooled radial aero engine first developed in 1936. The Pelides Major was a projected but unbuilt development as were the Alcides, Alcides Major and the Maeonides Major, the Alvis aircraft engine range taking their names from Greek mythology.
The Wright Whirlwind was a family of air-cooled radial aircraft engines built by Wright Aeronautical. The family began with nine-cylinder engines, and later expanded to include five-cylinder and seven-cylinder varieties. Fourteen-cylinder twin-row versions were also developed, but these were not commercially produced.
Lawrance Aero Engine Company was an American aircraft engine manufacturer. Founded by engine pioneer Charles Lawrance, it designed one of the first successful air-cooled radial engines. It existed for only 5 years, being acquired by Wright Aeronautical, a much larger company better able to mass-produce Lawrance's radial engines.
The Pratt & Whitney R-1860 Hornet B was a relatively uncommon aircraft engine. It was a development of Pratt & Whitney's earlier R-1690 Hornet and was basically similar, but enlarged in capacity from 1,690 to 1,860 cubic inches (30.5 L). Cylinder bore was increased by 1/8" and the crankshaft stroke by 3/8". Both engines were air-cooled radial engines, with a single row of nine cylinders.
The R-4090 Cyclone 22 was an experimental radial piston engine designed and built in prototype form in the United States during the 1940s.
The Nakajima Ha5 is a twin row, 14 cylinder air-cooled radial aircraft engine built by the Japanese Nakajima Aircraft Company. The engine was a development of earlier single-row Japanese engines, the Kotobuki and Hikari, which had combined features of the Bristol Jupiter and Pratt & Whitney R-1340 Wasp designs.
