Liberty L-12

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Liberty L-12-1

The Liberty L-12 was a 27 litre water-cooled 45 degree V-12 aircraft engine of 400 horsepower (300 kW).

It was designed by Jesse Vincent and E. J. Hall of the Hall-Scott Motor Co. and manufactured by Packard, Lincoln, Ford, General Motors, Nordyke and Marmon during the 1st world war. It was a modular design where 4 or 6 cylinders could be used in one or two banks. 20,478 were built between July 4, 1917 and 1919. Displacing 1,650 cubic inches, bore was 5 inches (127 mm) and stroke 7 inches (178mm). A single overhead camshaft for each cylinder bank operated 2 valves per cylinder. Dry weight was 383kg and takeoff power at 2,000 rpm was 449 hp. Two examples of a six-cylinder version, the Liberty L-6, were produced but not procured by the Army. Both were destroyed by Dr. William Christmas testing his so-called "Christmas Bullet" fighter.

An inverted Liberty 12-A was also referred to as the V-1650 and was built up to 1926....the exact same designation later applied, due to an identical displacement figure for the two engines, to the World War II Packard car company built examples of the Rolls-Royce Merlin upright V-12 aviation engine engine of World War II.

The engine was also produced in the UK for tank use as the Nuffield Liberty.

[edit] Specifications (Liberty L-12)

General characteristics

Type: 12-cylinder liquid-cooled Vee piston aircraft engine
Bore: 5 in (127 mm)
Stroke: 7 in (178 mm)
Displacement: 1,650 in³ (27 L)
Dry weight: 845 lb (383 kg)

Components

Valvetrain: One intake and one exhaust valves per cylinder operated via a single overhead camshaft per cylinder bank
Cooling system: Liquid-cooled