Man D2868 LE426, Operating Instruction

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Design and Function
MAN marine diesel engines D2868 LE4.. / D2862 LE4..
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Carefully read through the Operating Instructions before starting any work!
This particularly applies to the General Safety Instructions section
and the safety instructions in the various chapters.
4 Design and function
4.1 Engine application fields
The D2868 LE4.. (V8) and D2862 LE4.. (V12) marine engines are suitable for powering marine vessels for
light-duty applications.
Correlation of the engine types to the approved modes of operation, see "Technical Data" on page 106.
Typical applications
Light Duty: Pleasure crafts, escort and patrol boats, ambulance boats
4.2 Engine construction and engine equipment
The D2868 LE4.. engines are 8-cylinder 4-stroke, the D2862 LE4.. engines are 12-cylinder 4-stroke diesel
engines with turbocharging and intercooling.
Split crankcase, wet cylinder liners made of highly wear-resistant special centrifugal casting, steel pistons
with cooling duct for piston cooling. Single cylinder heads with shrink-fitted valve seats and pressed-in
valve guides. 4 valves per cylinder. Valve timing by means of central camshaft, roller tappets, tappet push
rods and rocker arms (OHV).
Injection system
High-pressure common-rail injection system in conjunction with EDC7 (Electronic Diesel Control).
Fuel system
Low-pressure system consisting of fuel lines, the hand pump and the fuel filters.
High-pressure system consisting of the volume-controlled high-pressure pumps, flange-mounted fuel
pumps and the rails with rail pressure sensor and pressure limiting valve.
Engine Lubrication
Force-feed lubrication for all bearing points. 2 rotor-type oil pumps driven by the crankshaft.
2 oil modules consisting of oil cooler, oil separator and oil pressure control valve.
Oil injection nozzles for piston cooling.
Cooling System
The engine is liquid-cooled. The cooling system is configured as an overpressure system. The cooling cir­
cuit is a thermostat-controlled forced-circulation system.
The maintenance-free coolant pump is mounted on the front end of the engine and is driven by a gear set.
Elastomer elements absorb the transmission of the crankshaft's torsional vibrations.
The heat exchanger and intercooler are cooled with seawater.
Intake and Exhaust System
The intake air flows to the exhaust turbochargers via the air filters. The then precompressed charge air is
recooled when it flows through the intercooler before being supplied to the engine.
The exhaust manifolds are cooled by the engine coolant. The gear-driven sea water pump is mounted on
the flywheel housing.