Liberty L-12
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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 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
Performance
- Power output: 449 hp (335 kW) at 2,000 rpm for takeoff
- Specific power: 0.27 hp/in³ (12.4 kW/L)
- Power-to-weight ratio: 0.53 hp/lb (0.87 kW/kg)
