Wright R-975 Whirlwind
R-9 piston aircraft engine, final nine cylinder series of the Whirlwind
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 975 cu in (15.98 L), and power ratings ranging from 300 hp (220 kW) to 550 hp (410 kW), depending on variant and rating basis. They were the largest members of the Wright Whirlwind engine family to be produced commercially, and they were also the most numerous.
During World War II, Continental Motors built the R-975 under license as a powerplant for Allied tanks and other armored vehicles. Tens of thousands of engines were built for this purpose, dwarfing the R-975's usage in aircraft, where it was overshadowed by the similar Pratt & Whitney R-985. After the war, Continental continued to produce its own versions of the R-975 into the 1950s; the Continental R-975-46A was rated at 550 hp (410 kW) at 2,400 rpm.
The R-975 powered the American World War II M18 Hellcat tank destroyer, which is claimed to have been the fastest tracked armored fighting vehicle ever built.
Design and development
Wright introduced the J-6 Whirlwind family in 1928 to replace the nine-cylinder R-790 series. The J-6 family included varieties with five, seven, and nine cylinders. The nine-cylinder version was originally known as the J-6 Whirlwind Nine, or J-6-9 for short.
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This entry incorporates text from “Wright R-975 Whirlwind” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.