Talk:Jacobs R-755

Why two designations (R-755 and L-4)? Drutt (talk) 21:44, 18 February 2009 (UTC)


 * Actually, this is commonplace for U.S. aircraft engines; the manufacturer had its own designation scheme, while the U.S. military had another. Jacobs originally called this engine the L-4. The U.S. military designated aircraft engines based on their layout and displacement: in this case, R stood for "radial", and "755" was the displacement in cubic inches (to the next lower multiple of 5). With so many engines made for the military during World War II, some manufacturers eventually changed their own designation schemes to better match the military one. --Colin Douglas Howell (talk) 22:39, 24 November 2018 (UTC)