V12 engine
The Orleans Motor Company built a massive 56.8 L (3,464 cu in) flathead V12 engine with a power output quoted as "nearly 298 kW (400 bhp)".
This engine had a V-angle of 60 degrees, air cooling and an intake over exhaust (F-head) valve arrangement.
[5] The Renault engine was closely mimicked by the RAF 4 and its derivatives,[citation needed] which was used by various British military aircraft during World War I.
The RAF 4 engine had a displacement of 13.2 L (806 cu in), weighed 289 kg (637 lb) and produced 104 kW (140 hp) at 1,800 rpm.
The production version was rated at 168 kW (225 hp) at 2,000 rpm, making it the most powerful airplane engine in Great Britain at the outbreak of World War I.
In Austria, the Austro Daimler V12 engines were used by the large flying boats of the Naval Air Force and produced up to 257 kW (345 hp).
By the end of World War I, V12s were well established in aviation, powering some of the newest and largest fighter and bomber airplanes.
The only American-design inverted V12 engine of any type to see even limited service in World War II was the air-cooled Ranger V-770, which was used in aircraft that were only used for training purposes within the United States, such as the Fairchild AT-21 Gunner.
The Rolls-Royce Merlin V12 engine was used in several British aircraft including the Hawker Hurricane and Supermarine Spitfire fighters, and the Avro Lancaster and de Havilland Mosquito bombers.
The long, narrow configuration of the V12 contributed to good aerodynamics, while its smoothness allowed its use with relatively light and fragile airframes.
In the United States, the Rolls-Royce Merlin engine was produced under license by Packard Motor Car Company, which was used in the P-51 Mustang fighter.
The Allison V-1710 was the only liquid-cooled V12 engine designed in the United States that was used on active service during World War II.
It was initially used in the P-38 Lightning, but the turbosupercharger system required bulky ductwork and had poor high-altitude performance.
One of the earliest recorded uses of V12 engines in automobiles was in October 1913, when a custom-built racing car competed at the Brooklands circuit in the United Kingdom.
[5] The V12 engine had a displacement of 9.0 L (549 cu in), an aluminum crankcase, iron cylinders with L-shaped combustion chambers, a cam-in-block valvetrain and a V-angle of 60 degrees.
Valve clearance was set by grinding the relevant parts, the engine lacking any easy means of adjustment.
As initially built, the V12 was rated at 150 kW (200 bhp) at 2,400 rpm and weighed approximately 340 kg (750 lb).
The lack of vibration and sound, inherent smoothness, and increased power were cited as key benefits for V12 engines.
Following the end of the Second World War, the economic austerity and changes in taste in many European countries led to the demise of luxury automobiles with V12 engines in the 1940s and 1950s.
The American manufacturers focused on continuously improving V8 engines and their performances through the 1950s, leading to the first "horsepower war" in the 1960s.
However, Cadillac was unsatisfied with the performance of its V12 engine, having little advantage over the large displacement V8 that was cheaper to enlarge for more power.
The most powerful naturally-aspirated V12 engine used in Formula One was the Tipo 043, used by Ferrari in 1994, which produced 850 hp (630 kW) @ 15,800 rpm.
[29] In prototype sports car racing, the highly successful 2006–2008 Audi R10 TDI used a diesel twin-turbo V12 engine.
In Japan, Isuzu produced naturally aspirated V12 diesel engines from 14.0 to 22.0 L (854 to 1,343 cu in) in 1976–2000, for their heavy duty trucks: New Power, 810 and Giga.
In 1931, American La France began producing firetrucks with V12 gasoline engines based on the Lycoming BB motor.
