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MAN Energy Solutions

L21/31, L21/31DF-M

Discover our highly reliable 2- & 4-stroke engines. Plus propeller & aft equipment ✓ turbochargers ✓ digitalization ✓ cryogenic technologies ✓ Find out more here.

Per Hersteller-Datenblatt
Capacity
HFO / VLSFO / MGO
Medium

Components & Design

Component data being added…

Technical Data

Swept volume per cylinder 10.74 L / 10.7 dm³
Compression ratio 15.5:1
Maximum combustion pressure 200 bar
Specific Fuel Oil Consumption (SFOC) 183-192 g/kWh (genauere Werte: 183 g/kWh bei 85% Last, 180 g/kWh Part-Load optimiert, 189-192 g/kWh je nach Konfiguration)
Specific lubrication oil consumption <0.8 g/kWh
Power per cylinder 220 kW
Stroke/Bore ratio 1.48:1
Turbocharging system MAN TCR constant pressure mit Jet Assist und Interkühlung
Power-to-weight ratio 18.4-22.5 kg/kW
Emission compliance IMO Tier II + IMO Tier III (mit MAN SCR)

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Common failures & inspection points

Piston ring stiction and breakage due to carbon deposits in grooves - Rings may seize and rupture causing severe liner damage. Residue buildup between ring groo
Cylinder liner scuffing and wear due to inadequate lubrication film - occurs when lubricant breaks down between piston rings and liner, leading to micro-welding
Exhaust valve deposits and carbon buildup - Salt deposits in fuel increase combustion space fouling. L21/31 design includes valve rotators to ensure even temper
Water contamination in fuel system - Four-stroke fuel-injected engines rely entirely on fuel for high-pressure pump lubrication; water kills the fuel pump faste
Turbocharger fouling and excessive play - Turbocharger inspection required for fouling, bearing play exceeding limits, or oil leakage (class-wide issue for all

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

Service & Maintenance

Wartung per Hersteller-Handbuch und Klassifikationsgesellschafts-Anforderungen. Jährliche Inspektion bei Class Survey. Ersatzteile per Herstellerangabe bevorraten.

Suppliers & Spare Parts

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Replacement Parts

Ersatzteile über MAN Energy Solutions, branch of MAN Energy Solutions SE, Germany oder zugelassene Vertriebspartner. Lead time: 2-6 Wochen.
Equipment Model #1718 · ✓ still in production