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The six-cylinder version of the W7 was used by the Swedish Army to power generators and as a marine engine. The Navy used twin engines in their small minesweepers. 


This example was used to provide stanby power at Boden fortress in Sweden in the event of an enemy destroying the power station in Harsprånget.

When the Second World War broke out, Sweden was isolated and the need for domestically-produced engines increased. Bolinder-Munktell then had to realign itself to develop equipment for the armed forces, including the six-cylinder version of the W7.

The W7 engine was also produced in 1, 2, 3 and 4-cylinder versions from the early 1930s and up until 1951. Today it is regarded as the period's most modern hot bulb engine and one of the last models developed by Bolinder-Munktell.

The six-cylinder engine had aluminium alloy pistons. This allowed the engine speed to be raised by 200 r/min compared with the other W7 engines. The engine is pravtically vibration-free.

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Bolinder's W7 S6


Introduced                     Early 1930s

Engine                             6-cyl, 2-stroke hot bulb engine

Engine output                180 hp, 1000 r/min

Serial number                34960 / 65

Generator output          150 kVA

Generator made by       ASEA