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.
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.