Liberty L-12
V-12 piston aircraft engine
The Liberty L-12 is an American water-cooled 45° V-12 engine, displacing 1,649 cubic inches (27 L) and making 400 hp (300 kW), designed for a high power-to-weight ratio and ease of mass production. It was designed principally as an aircraft engine and saw wide use in aero applications. It also saw marine use (both in racing and in runabout boats) once it was marinized; it was used in various military tanks; and in some race cars.
A single bank 6-cylinder version, the Liberty L-6, and V-8, the Liberty L-8, were derived from the Liberty L-12. It was succeeded by the Packard 1A-2500.
Development
In May 1917, a month after the United States had declared war on Germany, a federal task force known as the Aircraft Production Board summoned two top engine designers, Jesse G. Vincent (of the Packard Motor Car Company) and Elbert J. Hall (of the Hall-Scott Motor Company), to Washington. They were given the task of designing as rapidly as possible an aircraft engine that would rival if not surpass those of Great Britain, France, and Germany. The Board specified that the engine would have a high power-to-weight ratio and be adaptable to mass production.
The Board brought Vincent and Hall together on 29 May 1917 at the Willard Hotel in Washington, where the two were asked to stay until they produced a set of basic drawings. After just five days, Vincent and Hall left the Willard with a completed design for the new engine, which had adopted, almost unchanged, the single overhead camshaft and rocker arm valvetrain design of the later Mercedes D.IIIa engines of 1917–18.
“Liberty L-12” enters the record as v-12 piston aircraft engine. Crown Archives preserves that source wording while asking what Liberty, L-12 and V-12 can confirm, complicate or overturn.
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