Albert (Al) S. Menasco, a California native 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 US air races before World War II. Because Menasco engines were relatively light, they were successful in the hands of “golden age” air racing pilots. Menasco furnished special superchargers, cams, pistons, and other parts to achieve extra speed with available racing fuels. Menasco engines had a reputation for being temperamental screamers1 (and prone to overheating with improper air flow), but they could survive for a race in the right hands and lasted well in civil use.

Menasco made historically significant contributions to the development of aircraft piston engines, along the way earning a legendary reputation for these engines in air racing during the 1930s. Like many other notable American aircraft engine developers (e.g., the Wright Brothers, Glenn Curtiss, Balzer), Menasco had neither advanced training nor collegelevel engineering education on which to base his accomplishments with engines. Instead, he leveraged his exceptional skills as a mechanic and technician to design his outstanding engine series.