Mercedes-Benz OM352 engine

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The Mercedes Benz OM352 Engine is a 5657 cm2 (5.7 litres, 345 cubic inch) displacement inline 6 cylinder 4 stroke motor. The engine utilizes diesel fuel delivered in a direct injection method from a Bosch PES style inline injection pump to the combustion chamber.

Injection side of engine
Injection side of engine
Exhaust side of engine
Exhaust side of engine

Common output power can vary from 60 kW to 124 kW (80 to 168 hp) depending on the fuel delivery and air charge options.

Below is listed the specifications for a 130 hp (97 kW) OM352, model 353.961. This variant is commonly used in Mercedes Benz Unimog, such as the U1100 and U1300 models.


(information from the Unimog 435 Workshop manual, Book 1 Section 1.2/1)

Mercedes Benz Type: 352
Model: 353.961
Combustion System: Four-stroke diesel with direct injection
Number of cylinders, Cylinder arrangement: 6, vertical in-line
Bore: 97 mm
Stroke: 128 mm
Total displacement: 5657 cm²
Compression ratio: 17:1
Compression at starting speed: 22 bar up to 24 bar (2.2 to 2.4 MPa), minimum 20 bar
Continuous output at nominal speed: 96 kW (130 hp) @ 2800 rpm
Maximum torque at speed: 363 N·m (267 ft·lbf) @ 1700 rpm
Idle Speed: 700 rpm
Start of fuel delivery before TDC: 18 degrees
Injection Sequence: 1 - 5 - 3 - 6 - 2 - 4
Valve clearance, cold: (inlet 20 mm) (exhaust 30 mm)
Opening pressure of injection nozzles: 200 bar (20 MPa) + 10 (new), 180 bar minimum (used)
Operating temperature: 95 degrees Celsius
Oil pressure: nominal 2–5 bar (200–500 kPa), idle min 0.6 bar
Weight, dry: 460 kg, 1014 lb