The Jacobs Aircraft Engine Company was formed in 1930. An early product was a small 55 hp 3 cylinder engine. By 1933, Jacobs had developed its most famous engine, the L-4, better known as by its military designation, the R-755.

Jacobs R-755

In 1933, Jacobs enlarged their 7 cylinder radial engine from 589 to 757 cubic inches to create the L-4. The L-4 (or R-755) was a very successful engine with Page Industries manufacturing small numbers as late as the 1970s.


  • R-755-7: 225 hp (168 kW)
  • R-755-9: 245 hp (182 kW)
  • R-755-A2: 300 hp (224 kW)


  • Seven-cylinder, air cooled, radial engine
  • Displacement: 757 cubic inches (12.4 litres)

used by

  • Cessna UC-78 Bobcat
  • Cessna 195
  • Stearman PT-18 Kaydet