Mercedes-Benz OM621 engine

Reciprocating internal combustion engine
  • 1.9 L (1,897 cc)
  • 2.0 L (1,988 cc)
  • 2.2 L (2,197 cc)
Cylinder bore85–87 mm (3.35–3.43 in)Piston stroke83.6 mm (3.29 in)Cylinder block materialCast IronCylinder head materialCast IronValvetrainSOHCCompression ratio18.0:1CombustionFuel systemIndirect injectionFuel typeDieselCooling systemWater cooledOutputPower output35–40 kW (47–54 hp)Torque output108–118 N⋅m (80–87 lb⋅ft)ChronologyPredecessorMercedes-Benz OM636 engineSuccessorMercedes-Benz OM615 engine

The OM621 is an inline-four diesel engine produced by Mercedes-Benz, from 1956 to 1968. It was succeeded by the OM615 engine.

Design

The OM621 is based on the petrol M121 engine, but features revised camshafts, cylinder head, pistons, and fuel injection system.[1] In 1961, the engine capacity was increased to 2.0 L (1,988 cc) and power was uprated to 55 PS (40 kW) for use in the newly introduced W110 models. After being replaced by the OM615, a 2.2 L (2,197 cc) updated version of the OM621 engine was used solely in Unimog vehicles until 1988.[2]

Models

Engine Displacement Power Torque Years
OM621 I 1.9 L (1,897 cc) 37 kW (50 PS)
at 4,000 rpm
108 N⋅m (80 lb⋅ft)
at 2,200 rpm
1958–1959
OM621 IV 2.0 L (1,988 cc) 35 kW (48 PS)
at 3,800 rpm
1961–1962
OM621 III / VIII 40 kW (55 PS)
at 4,200 rpm
118 N⋅m (87 lb⋅ft)
at 2,400 rpm
1961–1968
2.2 L (2,197 cc) 40 kW (55 PS)
at 3,000 rpm
1966–1988

OM621 (37 kW version)

OM621 (35 kW version)

OM621 (40 kW version)

References

  1. ^ Long, Brian (2014-01-31). Mercedes-Benz 'Fintail' Models: The W110, W111 and W112 Series. Crowood. ISBN 9781847976048.
  2. ^ "1964-1993". www.mercedes-benz.co.uk. Retrieved 2018-07-22.