The Wright Whirlwind was a family of air-cooled
radial aircraft engine
An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many ...
s built by
Wright Aeronautical (originally an independent company, later a division of
Curtiss-Wright). 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.
The Whirlwind series was succeeded by more powerful but still air-cooled radial aero engines, notably the
Pratt & Whitney Wasp series and the
Wright Cyclone series.
Description
The Whirlwind was a direct descendant of the
Lawrance J-1, a nine-cylinder air-cooled radial built by the
Lawrance Aero Engine Company
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 Aeronau ...
for the U.S. Navy. Because the Navy was very enthusiastic about air-cooled radials, but was concerned that Lawrance could not produce enough engines for its needs, it forced Wright to purchase the Lawrance company in 1923 and build the J-1 itself. Wright's J-1 was the first engine in its nine-cylinder
R-790 Whirlwind
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 and around . These engines were the earliest members of the Wright Whirlwi ...
series and was quickly followed by the J-3, J-4, J-4A, J-4B, and finally the popular and successful J-5 of 1925.
In 1928, Wright replaced the R-790 series with the J-6 Whirlwind family, in which a
supercharger
In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement.
The current categorisation is that a supercharger is a form of forced induct ...
was added to boost engine power and the cylinders were enlarged by expanding the
bore
Bore or Bores often refer to:
*Boredom
* Drill
Relating to holes
* Boring (manufacturing), a machining process that enlarges a hole
** Bore (engine), the diameter of a cylinder in a piston engine or a steam locomotive
** Bore (wind instruments), ...
. This family included three members: the nine-cylinder
R-975
The Wright R-975 Whirlwind was a series of nine-cylinder air-cooled radial aircraft engines built by the Wright Aeronautical division of Curtiss-Wright. These engines had a displacement of about and power ratings of . They were the largest me ...
, the seven-cylinder
R-760, and the five-cylinder
R-540, providing a range of different power levels using the same basic design. Of these, the R-975 proved the most popular, especially because of its use in
armored fighting vehicles during
World War II.
During the mid-1930s, Wright also developed two fourteen-cylinder double-row versions of the Whirlwind, the R-1510 of , and the R-1670 of . These were used in a number of military aircraft prototypes, but neither engine reached the production stage.
Air-cooled Whirlwinds were lighter and more reliable than liquid-cooled engines of similar power, since a liquid cooling system added weight and required extra maintenance. Thanks to these advantages Whirlwind engines were used widely and were built in large numbers. Licensed copies were produced by manufacturers such as
Continental Motors,
Hispano-Suiza
Hispano-Suiza () is a Spanish automotive–engineering company. It was founded in 1904 by Marc Birkigt and Damian Mateu as an automobile manufacturer and eventually had several factories in Spain and France that produced luxury cars, aircraft en ...
, and adapted for
Soviet government production by the
Shvetsov OKB-19 design bureau. The Whirlwind's success led to the development of other air-cooled radial engines throughout the 1920s, 1930s, and 1940s.
Whirlwind series
*
J-5 / R-790: 9-cylinder radial, . Produced 1923-1928.
*
J-6-5 / R-540: 5-cylinder radial, . Produced 1928-1937.
*
J-6-7 / R-760: 7-cylinder radial, . Produced 1928-1945.
*
J-6-9 / R-975: 9-cylinder radial, . Produced 1928-1950s.
*
R-1510: 14-cylinder twin-row radial, . Introduced 1933, prototypes only.
*
R-1670: 14-cylinder twin-row radial, . Introduced 1934, prototypes only.
See also
*
Whirlwind Glaciers in
Antarctica named after the Wright Whirlwind series
USGS site
/ref>
References
*
* . Available from the Aircraft Engine Historical Society'
reference page
* . Available from the Aircraft Engine Historical Society'
reference page
{{US military piston aeroengines
Aircraft air-cooled radial piston engines
1920s aircraft piston engines