"> MAN Energy Solutions 20V35/44DF
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Engines
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MAN Energy Solutions

20V35/44DF

The MAN 20V35/44DF is a V‑20, four‑stroke trunk piston main engine delivering up to 11 200 kW at 720 rpm, capable of running on LNG or HFO (dual‑fuel) with low specific fuel consumption and Tier III NOx compliance in gas mode.

MAN Energy Solutions 20V35/44DF
11200.0 kW
Power

Engine Specifications

20
Cylinders
350 mm
Bore
440 mm
Stroke
4-stroke
Stroke Type

Components & Design

Component data being added…

Technical Data

Displacement per cylinder 42.3 liters
Power per cylinder @ 750 rpm 530 kW (L35/44DF standard); 560 kW (L35/44DF CD)
MEP (Mean Effective Pressure) 20.0–20.1 bar
SFOC liquid fuel @ 85% MCR 175.5 g/kWh
SFC gas operation 7440 kJ/kWh
Dry mass – 6L/7L/8L/9L/10L 40.5 / 45.6 / 50.7 / 55.0 / 59.7 tonnes
Methane slip reduction (CD variant) 85% vs. industry standard
Emissions compliance IMO Tier II (diesel) / Tier III (gas)
power kw 11200
rpm 720
fuel type LNG/HFO (Dual-Fuel)
configuration V

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Common failures & inspection points

Methane slip via scavenging leakage – unburned methane escapes to exhaust when gas injection occurs before exhaust valve closure; mitigated in CD variant via op

Monitor exhaust methane concentrations; inspect valve timing; verify adaptive combustion control (ACC) system calibration

Combustion instability at low load (<0% MCR) in gas mode – risk of pre-ignition, knocking, and transient power loss during load fluctuations or fuel-quality var

Review engine load profiles during dredger/auxiliary duty; check fuel-gas methane number (spec ≥70 MN); monitor combustion pressure transients

Crankcase explosion hazard during transient operation – accumulation of unburned gas and oil mist in crankcase when switching fuels or under rapid load changes;

Inspect crankcase ventilation filter; check scavenging air receiver for oil/liquid accumulation; monitor crankcase pressure during fuel transitions

Fuel injection nozzle/pilot-fuel system fouling – common-rail pilot-fuel system susceptible to coke deposit buildup and relief-valve drift under variable dual-f

Periodic fuel nozzle inspection; relief valve pressure setting verification; fuel system cleanliness monitoring

Turbocharger bearing accelerated wear under rapid load transients – MAN documentation acknowledges the 35/44DF 'handles high load-fluctuations' in dredger duty,

Monitor turbocharger oil outlet temperature; inspect bearing clearance during scheduled maintenance; verify steady oil-supply pressure under transient load

Type-general inspection and maintenance points for this equipment category — not model-specific.

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Equipment Model #123340 · ✓ still in production