W engine

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Napier Lion W12 aircraft engine (circa 1930) Napier Lion W12 @ Brooklands Museum.JPG
Napier Lion W12 aircraft engine (circa 1930)

A W engine is a type of piston engine where three or four cylinder banks use the same crankshaft, resembling the letter W when viewed from the front. [1] [2] [3]


W engines with three banks of cylinders are also called "broad arrow" engines, due to their shape resembling the British government broad arrow property mark. [1] [4]

W engines are less common than V engines. Compared with a V engine, a W engine is typically shorter and wider.

W3 engines

1906 Anzani 3-cylinder motorcycle engine Anzani, Alessandro W-3 1906.GIF
1906 Anzani 3-cylinder motorcycle engine

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 first airplane to fly across the English Channel.[ citation needed ]

The Feuling W3 is a 2.5 L (153 cu in) motorcycle engine that was built by an aftermarket parts company in the United States in the early 2000s. [5] Like radial aircraft engines it has a master connecting rod and two slave rods connected to the pistons. [6]

W6 engines

The Rumpler Tropfenwagen had a Siemens and Halske-built [7] 2,580 cc (157 cu in) overhead valve W6 engine, with three banks of paired cylinders, all working on a common crankshaft. [7] [8]

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.[ citation needed ]

W12 engines

Napier Lion VII NapierLion VII 1.jpg
Napier Lion VII

W12 engines with three banks of four cylinders were used by several aircraft engines from 1917 until the 1930s. A three-bank design was also used for an unsuccessful W12 engine which was intended to compete in Formula One in 1990.[ citation needed ]

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.[ citation needed ]

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. This type of engine can also be found in the Bugatti Veyron, Chiron, Divo and their related models.[ citation needed ]

Higher configurations

W18 engines

Operation of a three-bank W engine W-Engine with 60 Degree angle.gif
Operation of a three-bank W engine

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

W24 engine

The Allison V-3420, manufactured by the Allison Engine Company, is an example of a W24 engine.[ citation needed ]

W30 engine

The Chrysler A57 multibank, essentially five 250.6 cu in (4.1 L) Chrysler flathead engines driving one output shaft through a gear train, saw action during World War II. Developed in 1941, it would be used inside variants of the M3 Lee and M4 Sherman tanks, all deployed on the Western Front. [9] The A57 is the only example of a five-bank W configuation. [ citation needed ]

See also

Related Research Articles

V6 engine Piston engine with six cylinders in a "V" configuration

A V6 engine is a six-cylinder piston engine where the cylinders share a common crankshaft and are arranged in a V configuration.

Radial engine Reciprocating engine with cylinders arranged radially from a single crankshaft

The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is called a "star engine" in some languages. The radial configuration was commonly used for aircraft engines before gas turbine engines became predominant.

Straight engine Type of engine

The straight or inline engine is an internal combustion engine with all cylinders aligned in one row and having no offset. Usually found in four, six and eight cylinder configurations, they have been used in automobiles, locomotives and aircraft, although the term in-line has a broader meaning when applied to aircraft engines, see Inline engine (aviation).

The engine configuration describes the fundamental operating principles by which internal combustion engines are categorized.

Flat engine Combustion engine using pistons facing to the sides on a common crankshaft

A flat engine, also known as a horizontally opposed engine, is a piston engine where the cylinders are located on either side of a central crankshaft. A flat engine should not be confused with the opposed-piston engine, in which each cylinder has two pistons sharing a central combustion chamber.

Flat-four engine

A flat-four engine, also known as a horizontally opposed-four engine, is a four-cylinder piston engine with two banks of cylinders lying on opposite sides of a common crankshaft. The most common type of flat-four engine is the boxer-four engine, each pair of opposed cylinders moves inwards and outwards at the same time.

Straight-six engine Internal combustion engine

The straight-six engine is an internal combustion engine, with six cylinders mounted in a straight line along the crankcase with all the pistons driving a common crankshaft.

Cylinder head Component of a cylinder of an internal combustion engine

In an internal combustion engine, the cylinder head sits above the cylinders on top of the cylinder block. It closes in the top of the cylinder, forming the combustion chamber. This joint is sealed by a head gasket. In most engines, the head also provides space for the passages that feed air and fuel to the cylinder, and that allow the exhaust to escape. The head can also be a place to mount the valves, spark plugs, and fuel injectors.

W12 engine

A W12 engine is a twelve-cylinder piston engine which uses a W configuration.

VR6 engine Motor vehicle engine

VR6 engines are V6 piston engines with a narrow angle between the cylinder banks and a single cylinder head covering both banks of cylinders.

W16 engine

A W16 engine is a sixteen cylinder piston engine with four banks of four cylinders in a W configuration.

Overhead camshaft engine Valvetrain configuration

An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion chamber in the engine block.

A V5 engine is a five-cylinder piston engine where the cylinders share a common crankshaft and are arranged in a V configuration.

Anzani 10-cylinder 1910s French aircraft piston engine

The Anzani 10 was a 1913 10-cylinder air-cooled radial aircraft engine. It powered several experimental aircraft and also the later production versions of the Caudron G.3 reconnaissance aircraft, the Caudron G.4 bomber/trainer and the first production Cessna, the Model AA.

V8 engine Piston engine with eight cylinders in vee configuration

A V8 engine is an eight-cylinder piston engine in which the cylinders share a common crankshaft and are arranged in a V configuration.

The VR5 engines are a family of petroleum fuelled Internal combustion engines developed by the Volkswagen Group and produced from 1997 to 2006. They are derived from the VR6 engine family, also developed by Volkswagen, but with one less cylinder. VR5 engines are narrow-angle V5 petrol engines, with a V angle of 15° and a displacement of 2,324 cc. The VR5 was the first production block to use five cylinders in a V design with a 15-degree angle.

Inline engine (aeronautics) Reciprocating engine arranged with cylinders in banks aligned with the crankshaft

In aviation, an inline engine is a reciprocating engine with banks of cylinders, one behind another, rather than rows of cylinders, with each bank having any number of cylinders, although more than six is uncommon. The major reciprocating-engine alternative configuration is the radial engine, where the cylinders are placed in a circular or "star" arrangement.

Split-single engine

In internal combustion engines, a split-single design is a type of two-stroke where two cylinders share a single combustion chamber.

Anzani 3-cylinder fan engines 1900s French piston aircraft engine range

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 thought to be the oldest airworthy engine in the world.


A desaxe engine, is one in which each cylinder is positioned with its exact center slightly offset from the center line of the crankshaft. "Désaxé", in French, means "unbalanced". Desaxe engines are usually automotive, but the term can also apply to steam engines.


  1. 1 2 Domonoske, Arthur Boquer; Finch, Volney Cecil (1936). Aircraft engines: theory, analysis, design, and operation (Engineering textbook). J. Wiley & Sons. p. 7. Retrieved 2014-04-25. The W, or broad arrow engine, has three rows of cylinders of which the central row is vertical with the other two rows forming equal angles with the vertical.
  2. Taylor, Charles Fayette (1985) [1968]. The Internal-combustion Engine in Theory and Practice: Combustion, fuels, materials, design. Massachusetts Institute of Technology. ISBN   0-262-70027-1. LCCN   84028885 . Retrieved 2013-12-17. W engine is similar to a V engine but with three banks of cylinders. The two V angles are usually equal.
  3. Rajput, R. K. (December 2005). Internal Combustion Engines. New Delhi, India: Laxmi Publications. ISBN   817008637X . Retrieved 2013-12-17. W-engine Same as V-engine except with three banks of cylinders on the same crankshaft.
  4. "The New Sunbeam Overhead Valve Type Engines", Aviation Week and Space Technology, McGraw-Hill, vol. 3, p. 32, 1917
  5. "About Us". www.feulingparts.com. Retrieved 4 November 2019.
  6. "Make Mine a Triple: The Feuling W3". Interlink Media. MotorcycleCruiser.com. October 2000. Retrieved 31 December 2009.
  7. 1 2 Wise, David Burgess (1974). "Rumpler: One Aeroplane which Never Flew". In Tom Northey (ed.). World of Automobiles. 17. London: Orbis. p. 1964.
  8. Rogliatti, Gianni (1973). Cyril Posthumus (ed.). Period Cars. Feltham, Middlesex, UK: Hamlyn. pp. 108–109. ISBN   0-600-33401-5.
  9. Popular Science, February 1944, p.7. https://books.google.com/books?id=oiUDAAAAMBAJ&printsec=frontcover&source=gbs_summary_r&cad=0_0#PPP1,M1