The Zvezda M503 (built at AO Zvezda at St Petersburg) is a maritime 7 bank, 42-cylinder diesel radial engine built in the 1970s by the Soviet Union. Its primary use was in Soviet missile boatss that used three of these engines and is in Russian e.g. Karakurt-class corvette.

This engine may have had other applications, but due to its extreme weight (), 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 including the gearbox, for use in the 4.5 ton tractor pulling class, making 8160 PS (6 MW) at 2,500 rpm.

Specifications (Zvezda M503A)

Zvezda engines

1. AO Zvezda

2. Zvezda M503, M533, M520 B

3. Zvezda M504 56 cylinders

4. Zvezda M401 V12 marine turbodiesel engine

5. Zvezda M150 Pulsar V12 800kW < 1,8 - 3 MW

6. ZE1600KZ ZE Energetika 4,8 MW V8 V12 < 3 - 5 or 7 MW

7. Zvezda M507 2 × 56 = 112 cylinders

8. Zvezda M501

9. KMZ RD production

10. ADG1000 ADG6000, 68B 68G, 85D 86B 86G at KMZ - RD and UDMZ

11. TM-300 inline 6 (460hp 200 350kW) or 8

12. various V12 V16 and V18 from 3 5 MW 58D/A/E up to 8 9 MW

13. 68B, 68G, 85D 86B 86G 8,8 MW V18

Comparable engines

• Napier Deltic

References