Zvezda M503

The Zvezda M503 was a maritime 7 bank, 42 cylinder diesel radial engine built in the 1970s by the Soviet Union. Its primary use was in Soviet missile boats that used three of these engines.

This engine may have had other applications, but due to its extreme weight (5,400 kg (11,900 lb)), it would have been limited to ground or naval applications.

A German tractor pulling team designed a vehicle, named "Dragon Fire", around a methanol-fueled version of this engine; this modified engine is said to weigh 3,200 kg (7,100 lb) including the gearbox, for use in the 5.4 ton tractor pulling class, making 8,000 hp (6,000 kW) at 2,500 rpm.

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