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 feat ...

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 connecti ...

, 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 Britis ...

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 ...

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, 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 fa ...

, 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 crank ...

and two slave rods connected to the pistons.

W6 engines

The Rumpler Tropfenwagen 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, 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, manufactured by the

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

, is an example of a W24 engine.

W30 engine

The Chrysler A57 multibank, essentially five Chrysler flathead engines 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 World War II by country, vast majority of the world's countries—including all of the great power ...

. 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 C ...

and

M4 Sherman } The M4 Sherman, officially Medium Tank, M4, was the most widely used medium tank by the United States and Western Allies in World War II. The M4 Sherman proved to be reliable, relatively cheap to produce, and available in great numbers. It ...

tanks, all deployed on the

Western Front Western Front or West Front may refer to: Military frontiers * Western Front (World War I), a military frontier to the west of Germany *Western Front (World War II), a military frontier to the west of Germany *Western Front (Russian Empire), a maj ...

.''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