Inline 7 Cylinder with firing order 1-3-5-7-2-4-6

A straight-seven engine or inline-seven engine is a

straight engine The straight engine (also called inline engine) is a configuration of multi-cylinder piston engine where all of the cylinders are arranged in a single row, rather than radially or in two or more cylinder banks. Design A straight engine is eas ...

with seven

cylinder A cylinder () has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infinite ...

s. 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 In mechanical engineering, a crosshead is a mechanical joint used as part of the slider-crank linkages of long stroke reciprocating engines (either internal combustion or steam) and reciprocating compressors to eliminate sideways force on the ...

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.

References

Straight-07 Seven-cylinder engines Straight-07 {{Mech-engineering-stub