The Kinner 5-cylinder radial engine was the work of Bert Kinner in his Los Angeles design office in the 1920s. Kinner initially designed aircraft, but lacking a suitable engine constructed a lightweight reliable engine. The aircraft are now mostly forgotten, but his name is still associated with a successful line of radial aircraft engines. The first engines were 3-cylinder air-cooled radials, followed by a large number of five cylinder engines. The final engine was the 300 horsepower Kinner C-7.
Amelia Earhart flew early models of Kinner aircraft and later became a sales representative for Kinner.
The Kinner B-5 was a popular engine for light general and sport aircraft. The B-5 was a development of the earlier K-5 with slightly greater cylinder bore and a corresponding increase in power. The B-5 was a rough running but reliable engine and the B-5 and its derivatives were produced in the thousands powering many World War II trainer aircraft. Its military designation was R-440.