X engine

X-engine according to US Patent 1889583 (Eingetragen 1928)[1]
Symmetrical X-Engine (90°/90°/90°/90°)

An X engine is a piston engine with four banks of cylinders around a common crankshaft, such that the cylinders form an "X" shape when viewed from front-on.

The advantage of an X engine is that it is shorter than a V engine of the same number of cylinders,[2] however the drawbacks are higher weight and complexity as compared to a radial engine. Therefore the configuration has been rarely used.

Several of the X engine designs were based on combining two V engines.


Only two examples of X engines are known to have reached production. The first was the 1939-1942 Rolls-Royce Vulture, a 42 L (2,563 cu in) X-24 aircraft engine which was built using two Rolls-Royce Peregrine V12 engines.[3] The Rolls-Royce Vulture was briefly used in the Avro Manchester heavy bomber, before engine failures caused it to be replaced by the Avro Lancaster (powered by the Rolls-Royce Merlin V12 engine).

The other production X engine is the 2015-present ChTZ Uraltrac cyrillic 12H360 (12N360) X-12 engine used in the Russian Armata tanks.[4]

Several prototype 24-cylinder X engines for military aircraft were developed during World War II, including the Daimler-Benz DB 604, Rolls-Royce Exe and Isotta Fraschini Zeta R.C. 24/60, along with the 16-cylinder Napier Cub.

Other prototype X engines include a 1920s Ford X-8 automotive engine, which was investigated during the development process of the Ford Flathead V8 engine.[5][6] During the 1960s, Honda is said to have experimented with an X-32 engine configuration for their Formula One racing efforts, but abandoned the design as being too complex and unreliable.[citation needed] From 2006-2010, the Revetec X4v1 and Revetec x4v2 X-4 experimental petrol engines were developed by an engine research company,[7][8] followed in 2013 by the Revetec X4-D1 experimental diesel engine.[9]

See also


  1. ^ "Internal combustion engine". www.google.co.in. Retrieved 30 November 2019.
  2. ^ "Henry Ford's Weird Old Engines". Popular Science. Bonnier Corporation: 64–67. August 1960.
  3. ^ Lumsden, Alec (2003). British piston aero-engines and their aircraft. Airlife. p. 200. ISBN 1-85310-294-6.
  4. ^ "Дизельный двигатель 12Н360". www.chtz-uraltrac.ru (in Russian). Archived from the original on 27 November 2015.
  5. ^ "Experimental Ford Engines". www.hemmings.com. Retrieved 6 December 2011.
  6. ^ "Henry Ford's X-8 engine and how it will be used to raise dollars for Autistic and other Special Needs children". www.lutheransonline.com. Archived from the original on 27 May 2011.
  7. ^ "Revetec Prototype Engines". www.revetec.com. Retrieved 30 November 2019.
  8. ^ "The Revetec X4v2". www. Retrieved 30 November 2019.
  9. ^ "Revetec Australia - News". www.revetec.com. Retrieved 30 November 2019.