The radial engine may have fallen far out of favor for internal combustion development over time, but some military vehicles got impressive results from them.

Bore and Stroke: 156 mm (6.125 in.) x 174 mm (6.875 in.) The Wright Cyclone series began in 1924 with a U.S. Navy contract for a nine-cylinder air-cooled radial engine having approximately the same ...

Bore and Stroke: 171 mm (6.8 in.) x 152 mm (6.0 in.) Following the departure of Frederick Rentschler and colleagues to form Pratt & Whitney, Charles Lawrance, who formerly headed his own company, ...