Aerial combat advanced at an astonishing rate during World War I, and though it seems unimaginable today, there were no American-designed aircraft deemed suitable for battle in the skies over Europe. There was a U.S.-designed engine in the fight however: the Liberty V-12 or L-12.

The L-12 engine was America’s greatest technological contribution to the aerial war effort. Its initial assignment was powering the “Liberty Plane” — a version of the British-designed De Haviland/Airco DH-4 bomber produced in the U.S. by Dayton-Wright in Dayton, Ohio; Fisher Body Corporation in Detroit, Michigan; and Standard Aircraft in New Jersey. In addition to powering the DH-4 and a variety of other airplanes, over its long service life the L-12 powered tanks, high-speed watercraft and land-speed racers.

The L-12 came about because Packard’s head of engineering, Jesse G. Vincent, recognized the need for a standardized line of aircraft engines that could be mass produced during wartime. The government assigned Vincent the task of creating this engine and teamed him up with Elbert J. Hall of the Hall-Scott Motor Company. The two met in Washington, D.C., on May 29, 1917, and, with the help of volunteer draftsmen, created detailed drawings and a full report by May 31. This original design was a V-8, but in their report Vincent and Hall outlined how the engine could be configured as a four-, six-, eight- or 12-cylinder engine.

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