Straight-seven engine explained

A straight-seven engine or inline-seven engine is a straight engine with seven cylinders. It is more common in marine applications because these engines are usually based on a modular design, with individual heads per cylinder.

Marine engines

Straight-seven engines produced for marine usage include:

• Wärtsilä-Sulzer RTA96-C two-stroke crosshead diesel engine^[1]
• Wärtsilä 32 trunk piston engines^[2]
• MAN Diesel IMO two-stroke crosshead diesel engine^[3]
• Burmeister & Wain 722VU37 two-stroke diesel engine (commenced 1937, used in the Danish Havmanden-class submarines
• Sulzer 7QD42 diesel engine (1939-1940, used in the Dutch O 21-class submarines).^[4]

Land use

The AGCO Sisu 98HD is a straight-seven diesel engine that was released in 2008.^[5] Intended for farming machinery, the engine shares various components with the company's straight-six engine.^[6]

Notes and References

1. Web site: Wärtsilä RT-flex 82T.
2. Web site: Wärtsilä 32.
3. Web site: MAN Diesel Marine Engine IMO Tier I Programme . 2011-03-07 . 2011-03-10 . https://web.archive.org/web/20110310040922/http://viewer.zmags.com/publication/fc38fd2e .
4. Book: Cummins, C. Lyle Jr. . 2007 . Diesels for the First Stealth Weapon . Carnot Press . 405,464 . 978-0-917308-06-2.
5. Web site: 7-Cylinder - AGCO Sisu Power. https://web.archive.org/web/20110707093317/http://www.agcosisupower.com/products/agco_sisu_power_engines/off-road_applications/7-cylinder/. 7 July 2011.
6. Web site: AGCO SISU POWER launched new innovative 7-cylinder 9,8 litre engine. 10 September 2008. https://web.archive.org/web/20160304033019/http://www.agcopower.com/company/news/?x1595371=1636279. 4 March 2016.