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
- Wärtsilä 32 trunk piston engines
- MAN Diesel IMO two-stroke crosshead diesel engine
- 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).
Land use
The AGCO Sisu 98HD is a straight-seven diesel engine that was released in 2008. Intended for farming machinery, the engine shares various components with the company's straight-six engine.
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