The Liberty L-6 was a six-cylinder
water-cooled
Cooling tower and water discharge of a nuclear power plant
Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water is inexpensive and non ...
inline aircraft engine
An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many ...
developed in the United States during
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
.
Design and development
![LIberty L-6 engine installed in captured Fokker D](https://upload.wikimedia.org/wikipedia/commons/5/52/LIberty_L-6_engine_installed_in_captured_Fokker_D.VII.jpg)
The Liberty L-6, which developed 200–215 hp, was built by the
Thomas-Morse Aircraft Corp. and
Wright Aeronautical Corp. Since it was based on the same engine design as the more successful
Liberty L-12
The Liberty L-12 is an American water-cooled 45° V-12 aircraft engine displacing and making designed for a high power-to-weight ratio and ease of mass production. It saw wide use in aero applications, and, once marinized Marinisation (also m ...
V-12 liquid-cooled aviation engine, the L-6's resemblance to the
Mercedes D.III
The Mercedes D.III, or F1466 as it was known internally, was a six-cylinder SOHC valvetrain liquid-cooled inline aircraft engine built by Daimler and used on a wide variety of German aircraft during World War I. The initial versions were introd ...
German aviation engine, the source for the Liberty V-12's own cylinder and valvetrain design, resulted in the American L-6 engine design bearing a close visual resemblance to the German straight-six aviation powerplant in a number of respects, with at least one L-6 even being mounted postwar into a captured
Fokker D.VII
The Fokker D.VII was a German World War I fighter aircraft designed by Reinhold Platz of the Fokker-Flugzeugwerke. Germany produced around 3,300 D.VII aircraft in the second half of 1918. In service with the ''Luftstreitkräfte'', the D.VII qu ...
fighter for testing in the US. The Liberty L-6's smaller displacement of some 825 cu. in. (13.5 liters) versus the late-war German Mercedes D.IIIaü's 903 cubic inches (14.8 liters) do not seem to have handicapped the American straight-six design, however, as the "Liberty Six" possessed a 5.42:1
CR, while the D.IIIaü had only a 4.64:1 CR, explaining a good bit of the American powerplant's output level—in addition to the 735.5 watt level for German ''Pferdestärke'' metric horsepower, versus the then solely-American-based
SAE
SAE or Sae may refer to:
Science and technology
:
* Selective area epitaxy, local growth of epitaxial layer through a patterned dielectric mask deposited on a semiconductor substrate
* Serious adverse event, in a clinical trial
* Simultaneous Auth ...
organization's standard of almost 746 watts per one horsepower.
Since the L-6 was too large for mail airplanes and other engines were available, the L-6 was canceled after only 52 had been built. In 1920 10 more L-6 engines were ordered, designated L-825, several of which were installed in the
Curtiss PN-1
The Curtiss PN-1 was an American single-seat night fighter biplane built by Curtiss Aeroplane and Motor Company using blueprints from the Engineering Division of the United States Army Air Service.
Development
Designed by the USAAC, the PN-1 w ...
, (only two built), and the
Engineering Division TW-1, (only six built).
Hall-Scott
Hall-Scott Motor Car Company was an American manufacturing company based in Berkeley, California. It was among the most significant builders of water-cooled aircraft engines before World War I.
History
1910–21
The company was founded in 1910 ...
also produced a six-cylinder engine using Liberty L-12 components, as the Hall-Scott L-6.
Specifications
See also
References
This article incorporates text from
Liberty L-6
/span>, a public domain work of the United States Government.
*
{{Liberty aeroengines
1910s aircraft piston engines
Straight-six engines