A W engine is a type of

piston engine A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common featu ...

where three or four cylinder banks use the same

crankshaft A crankshaft is a mechanical component used in a piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating shaft containing one or more crankpins, that are driven by the pistons via the connecting ...

, resembling the letter W when viewed from the front. W engines with three banks of cylinders are also called "broad arrow" engines, due to their shape resembling the British government

broad arrow A broad arrow, of which a pheon is a variant, is a stylised representation of a metal arrowhead, comprising a tang and two barbs meeting at a point. It is a symbol used traditionally in heraldry, most notably in England, and later by the Brit ...

property mark. W engines are less common than

V engine A V engine, sometimes called a Vee engine, is a common configuration for internal combustion engines. It consists of two cylinder banks—usually with the same number of cylinders in each bank—connected to a common crankshaft. These cylinder b ...

s. Compared with a V engine, a W engine is typically shorter and wider.

W3 engines

One of the first W engines was the

Anzani 3-cylinder From 1905 to 1915, Alessandro Anzani built a number of three-cylinder fan engines and radial engines, one of which powered Louis Blériot's 1909 cross-channel flight. An Anzani three-cylinder engine that powers a Blériot XI based in England is ...

, built in 1906, to be used in Anzani motorcycles. It is this W3 engine which also powered the 1909

Blériot XI The Blériot XI is a French aircraft of the pioneer era of aviation. The first example was used by Louis Blériot to make the first flight across the English Channel in a heavier-than-air aircraft, on 25 July 1909. This is one of the most fam ...

, the first airplane to fly across the English Channel. The ''Feuling W3'' is a motorcycle engine that was built by an aftermarket parts company in the United States in the early 2000s. Like radial aircraft engines it has a master

connecting rod A connecting rod, also called a 'con rod', is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the cranksh ...

and two slave rods connected to the pistons.

W6 engines

The

Rumpler Tropfenwagen The Rumpler Tropfenwagen ("Rumpler drop car", named after its raindrop shape) was a car developed by Austrian engineer Edmund Rumpler. The Tropfenwagen Aerodynamics Rumpler, born in Vienna, was known as a designer of aircraft when at the 1921 Ber ...

had a Siemens and Halske-built

overhead valve An overhead valve (OHV) engine, sometimes called a ''pushrod engine'', is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with earlier flathead engines, where the valves were located be ...

W6 engine, with three banks of paired cylinders, all working on a common crankshaft.

W8 engines

The sole W8 engine to reach production is the Volkswagen Group W8 engine automotive engine, which used a four-bank design and was produced from 2001-2004.

W12 engines

W12 engines with three banks of four cylinders were used by several aircraft engines from 1917 until the 1930s. A three-bank W12 design was also used unsuccessfully by the Life F1 team in the

1990 Formula One season The 1990 FIA Formula One World Championship was the 44th season of FIA Formula One motor racing. It featured the 1990 Formula One World Championship for Drivers and the 1990 Formula One World Championship for Constructors, which were conteste ...

, failing to qualify at every race. Although less commonly used in automobiles than V12 engines, a W12 petrol engine has been produced by Volkswagen Group since 2001. This four-bank engine—based on two VR6 engines with a common crankshaft—has been used in various cars sold under the Audi, Bentley and Volkswagen brands.

W16 engines

W16 engines are rarely produced, with the notable exception of the Volkswagen Group 8.0 WR16 engine that has been used since 2005. The W16 type of engine can also be found in the Bugatti Veyron,

Chiron In Greek mythology, Chiron ( ; also Cheiron or Kheiron; ) was held to be the superlative centaur amongst his brethren since he was called the "wisest and justest of all the centaurs". Biography Chiron was notable throughout Greek mythology ...

, Divo and their related models.

W18 engines

The W18 layout is rarely used, with the only production examples being several aircraft during the 1920s and 1930s, an
CRM Motori SpA marine engines

W24 engine

The

Allison V-3420 The Allison V-3420 was a large experimental piston aircraft engine, designed in 1937 by the American Allison Engine Company. Design and development In 1937, at the behest of the United States Army Air Corps, the Allison Engine Company agreed t ...

, manufactured by the

Allison Engine Company The Allison Engine Company was an American aircraft engine manufacturer. Shortly after the death of James A. Allison, James Allison in 1929 the company was purchased by the Fisher Body, Fisher brothers. Fisher sold the company to General Motors, ...

, is an example of a W24 engine.

W30 engine

The

Chrysler A57 multibank The Chrysler A57 Multibank is a 30-cylinder engine that was created in 1941 as America entered World War II. It consists of five banks of inline-6 cylinder engines. It was born out of the necessity for a rear-mounted tank engine to be developed ...

, essentially five

Chrysler flathead engine The Chrysler flathead engine is a Sidevalve engine, flathead automotive engine manufactured by the Chrysler Corporation from 1924 through the early 1960s. The flathead engine came in four-,six-, and eight-cylinder configurations and varying displa ...

s driving one output shaft through a gear train, saw action during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. Developed in 1941, it would be used inside variants of the

M3 Lee The M3 Lee, officially Medium Tank, M3, was an American medium tank used during World War II. The turret was produced in two forms, one for US needs and one modified to British requirements to place the radio next to the commander. In British Co ...

and

M4 Sherman } The M4 Sherman, officially Medium Tank, M4, was the most widely used medium tank by the Military history of the United States during World War II, United States and Allies of World War II, Western Allies in World War II. The M4 Sherman prove ...

tanks, all deployed on the Western Front.''Popular Science'', February 1944, p.7. https://books.google.com/books?id=oiUDAAAAMBAJ&printsec=frontcover&source=gbs_summary_r&cad=0_0#PPP1,M1 The A57 is the only example of a five-bank W configuration.

References

{{DEFAULTSORT:W Engine Piston engine configurations Engines by cylinder layout