The OM636 is a 4-cylinder, 4-stroke diesel engine. It was introduced in 1949. This engine has been installed in Mercedes-Benz passenger cars, vans and small trucks since the late 1940s.
The weak point of the engine is the thermal overload of the cylinder head, since the bridge between the valves is too narrow and heat is not dissipated. This can cause hairline cracks and water to enter the combustion chamber.
Mercedes diesel R4 family: OM636, OM621, OM615, OM616, OM601, OM661, OM604, OM611, OM668, OM640, OM646, OM651, OM654.
Specifications
| Production years | 1949-1990 |
| Displacement, cc | 1697 – 1767 |
| Fuel system | prechamber injection |
| Power output, hp | 25 – 43 |
| Torque output, Nm | 96 – 101 |
| Cylinder block | cast iron R4 |
| Block head | cast iron 8v |
| Cylinder bore, mm | 73.5 – 75 |
| Piston stroke, mm | 100 |
| Compression ratio | 19.0 |
| Turbocharging | no |
| Fuel type | diesel |
| Predecessor | OM138 |
| Successor | OM621 |
The motor is water cooled and has a thermostat with a short circuit cable. The engine block and cylinder head are made of gray cast iron, OM 636.912 and OM 636.915 have 2 valve covers, all other models have only one bore. Triple bearing crankshaft and connecting rods are forged from steel. The engine has overhead valves (2 per cylinder) and a lower camshaft driven by a pair of gears (OHV).
The inline injection pump from Bosch is driven by the camshaft via an additional pair of gears. Fuel is injected into the prechambers. The intake and front chambers are on the left, the exhaust, camshaft and injection pump are on the right. Model 636.914 has no injection time and is regulated at the final speed, while model 636.930 has an injection time. The pump is integrated in the cylinder head and is driven by a belt from the crankshaft.
Using OM636
- Farm Tractor D177 and D177S;
- Burer Special (UM4);
- Combine harvester Ködel & amp; Böhm KÖLA Combi, Lanz MD 18 S, Fahr MDL, Claas Columbus;
- Güldner A4M;
- Hanomag Pickup;
- Built-in motors for:
- power generators;
- forklift trucks;
- ships;
- refrigeration units.
Frequently asked questions about the Mercedes OM636
How much power does the Mercedes OM636 make?
The Mercedes OM636 develops 25 - 43 hp and 96 - 101 Nm of torque.
Is the Mercedes OM636 turbocharged?
No, the Mercedes OM636 is naturally aspirated.
