Albert S. Menasco, SAE member and distinguished aircraft engine designer active in the 1920s and 1930s, produced a series of inverted, inline, four- and six-cylinder, air-cooled engines that achieved great success in many U.S. air races before World War (WW) II. Menasco's engines found substantial use in such light airframes as the famous Ryan monoplane ST, but his company was not commercially successful until it shifted to manufacturing landing gear in the 1940s. Menasco's historical legacy in aircraft engines is a fine testimonial to U.S. engineering accomplishment.
This paper chronicles the engineering development of Menasco's relatively light aircraft engines and their air racing success in the hands of “golden age” pilots. Menasco furnished special superchargers, cams, pistons, and other parts to achieve extra speed with available racing fuels. His engines had a reputation for being somewhat temperamental (and prone to over-heating with improper air flow), but they could survive for a race in the right hands and lasted well in civil use. The paper also covers some unusual experimental Menasco engines, such as the Unitwin, special WW II R&D engines, and axial-flow turbojet engines.