Menasco Manufacturing was established by Albert Menasco in Los Angeles in 1926. The company's first product was an air-cooled rebuild of a Salmson radial.
In 1929, Menasco introduced the 4-A, the first of what was to become its main product line, the inverted, in-line engine.

Al Menasco’s air racing heritage, more than any other achievement, put his engines “on the map.” From 1930 to 1937, Menasco engines won three times as many air races in US and foreign closed course competition as all other brands combined. They totally dominated their size classes (discouraging the entry of rivals) and even scored key victories against much larger engines in Thompson Trophy national air races. The Menasco racing engines were major technical achievements, and only certain engineering obstacles forestalled even better results.

The company ended engine development and manufacturing after World War II. Most recently Menasco Aerospace was known for its landing gear and, as part of Coltec Industries, was acquired by Goodrich Aerospace in 1999.

Menasco C-4 Pirate

The Menasco C-4 was a enlarged B-4 with the bore increased from 4.5 to 4.75 inches. The C-4 was called the "Pirate", Menasco's trade name for its four-cylinder line.
The U.S. Military designation for the Menasco C-4 was the L-365.


  • L-365-1: 125 hp (93 kW)


  • Four cylinder, air-cooled, in-line, inverted
  • Displacement: 363 cubic inches (5.9 litres)
  • Bore x stroke: 4.75 x 5.125 inches

used by

  • Ryan XPT-16 Recruit