Wright Cyclone

Wright Cyclone was the name given to a family of air-cooled radial piston engines designed by Curtiss-Wright and used in numerous American aircraft in the 1930s and 1940s.

Cyclone family

File:Wright R-1820 G.jpg

Wright R-1820

• R-1300 Cyclone 7
• R-1820 Cyclone 9
• R-2600 Cyclone 14 (Twin Cyclone)
• R-3350 Cyclone 18 (Duplex Cyclone)

Background

The Wright Aeronautical Corporation was formed in 1919, initially to develop Hispano-Suiza engines under licence. The Corporation’s first indigenous design, the R1, was also the first successful high-powered radial in the USA. Funded by contracts from the US Navy for new air-cooled radials, Wright started a new design (initially called the P2) in 1924. The resignation of Frederick Rentschler to join Pratt & Whitney, along with several key engineering personnel, seriously affected the development of the P2 and it did not go into production.

R-1750 Cyclone 9

A new design was launched in 1926, known as the R-1750 Cyclone. This was a nine-cylinder radial with a displacement of 1750 cu in and internally-cooled exhaust valves. It was type-tested at 500 hp in 1927.

R-1820 Cyclone 9

Wright merged with Curtiss in 1929 and recovered from the loss of Rentschler and other engineering staff. In 1932, the R-1750 was developed to a capacity of 1823 cu in. This was the F model Cyclone, designated R-1820. This engine introduced a forged aluminium crankcase and was developed through the 1930s to reach 890 hp. It used a bought-in General Electric supercharger and Wright concluded that this feature limited the potential power output of the engine. For the next development, the G-Series of 1937, Wright developed its own single-speed supercharger. The G-series was developed to deliver 1200 hp at 2500 rpm and made up the bulk of R-1820 Cyclone production during World War 2. The final phase of development of the single row radial design was the H-Series at 1350 hp.

R-2600 Cyclone 14

Wright went on to develop two-row engines with 14 cylinders in two rows of 7, called the Cyclone 14, R-2600. This was installed in the Boeing 314, Grumman TBM/TBF Avenger, North American B-25 Mitchell, and some models of the Douglas A-20 Havoc (RAF Boston).

R-3350 Cyclone 18

The final Cyclone development was the 18 cylinder engine R-3350, called the Duplex Cyclone or Cyclone 18. Among other applications, it was installed in the Douglas Skyraider, but the most crucial military application for this engine was the B29 bomber, whose most memorable exploits were to carry the atomic bomb to Hiroshima and Nagasaki. In other commercial applications it stayed in production until 1957.

See also

• Pratt & Whitney Wasp - a comparable competing line of engines

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Wright Cyclone".