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Mitsubishi

5UEC43LSE

Name: Mitsubishi 5UEC43LSE
Brand: Mitsubishi
SKU: OSE-38574

The Mitsubishi 5UEC43LSE is a 5‑cylinder, low‑speed 2‑stroke main engine delivering 6 000 kW at 155 rpm, designed for direct‑drive propulsion on medium‑size cargo vessels.

6000.0 kW

Power

Engine Specifications

Cylinders

430 mm

Bore

1350 mm

Stroke

6,000 kW

MCR Power

155.0 rpm

MCR RPM

2-stroke

Stroke Type

Family: Mitsubishi UEC (LS/LA/LSE/LSII) · Tier: IMO Tier II · Fuel: HFO, MDO

Inspector Detail ✓ verified

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Designation decoded

5 = Number of cylinders (5 cylinders); UEC = Unified Exhaust-port Crosshead (Mitsubishi/J-ENG two-stroke crosshead engine series); 43 = Cylinder bore in cm (430 mm); LSE = Long Stroke Eco (long-stroke variant with ecological and economical optimization, improved SFOC)

Background

The 5UEC43LSE is a medium-sized two-stroke crosshead engine of the UEC series with 430 mm bore in the LSE variant (Long Stroke Eco). The LSE version offers lower specific fuel consumption and improved emission values compared to the standard LS version through optimized combustion parameters. The engine is designed for Handymax to Supramax bulk carriers and medium-sized tankers.

Calculated metrics

Stroke To Bore Ratio

3.14

Inspector checklist

Camshaft and control drive

Chain drive for wear, chain elongation and sprocket condition inspection
Inspect cam profiles for pitting, cracks and wear
Check camshaft bearing clearance and lubrication conditions
Verify and document valve timing

Fuel injection system and fuel

Einspritzpumpen-Zustand (Plunger, Buchse, Ventile) prüfen
Test fuel injectors for opening pressure, spray pattern and leakage
High-pressure fuel lines for fatigue and crack formation
Brennstoff-Lecköl pro Zylinder quantifizieren

Auslassventil

Valve stem and valve seat for corrosion and burning
Ventildrehvorrichtung Funktion prüfen
Ventilführung Verschleißmessung
Check valve lift and closing characteristics

Cylinder, piston and liner

Measure liner inner diameter at several heights and directions
Document piston ring wear limit and end clearance
Piston crown for thermal cracks, erosion and deposits
Inspect scavenge ports for blockage and edge breakage

Crosshead and running gear

Crosshead bearing clearance and oil supply
Piston rod surface and dimensional accuracy
Stuffing box rings condition and oil scraping
Kurbelwellen-Durchbiegung messen

Vibration damper and 5-cylinder aspects

Torsional vibration damper condition and silicone oil
Check barred speed range compliance and signage
Monitor axial vibrations and vibration damper

Logbook reference values

Parameter	Expected	Deviation means
Pmax (Zünddruck)	Gemäß Testbed-Protokoll, Zylinderabweichung < 3 bar	Uneven operation indicates fuel injection pump or compression differences
Exhaust gas temperature per cylinder	Gemäß Hersteller, Spreizung < 30°C	Elevated values indicate combustion problems or exhaust valve leakage
Pcomp (Kompressionsdruck)	Gemäß Shop-Test, Abweichung < 2 bar	Niedriger Wert weist auf Undichtigkeit (Ringe, Ventil, Laufbuchse) hin
Zylinderschmieröl-Feedrate	0.8–1.2 g/kWh	Incorrect adjustment leads to increased wear or coking
Kühlwassertemperatur Zylinderauslass	75–85°C	Deviation indicates cooling system disturbance or liner damage
Turbolader-Drehzahl	According to manufacturer specification at rated load	Deviation indicates turbine/compressor fouling or charge air cooler fouling

Common Failure Modes

Torsionsschwingungen (5-Zylinder)

Symptoms: Erhöhte Vibrationen, Kurbelwellen-Durchbiegungsanstieg, Schwingungsdämpfer-Temperaturerhöhung

Causes: 5-Zylinder-typische Schwingungsanregung, Schwingungsdämpfer-Alterung, Betrieb in verbotenen Drehzahlbereichen

Preventive: Schwingungsdämpfer gemäß Intervall überholen, Barred Speed Range strikt einhalten

Fuel injection pump wear

Symptoms: Leistungsungleichmäßigkeit, Rauchentwicklung, Abgastemperatur-Streuung

Causes: Katalysator-Fines im Brennstoff, Kavitation, Unzureichende Brennstoff-Reinigung

Preventive: Optimize fuel treatment, overhaul fuel injection pumps after operating hours

Auslassventil-Abbrand

Symptoms: Kompressionsverlust, erhöhte Abgastemperatur, Blow-by

Causes: Hot corrosion from heavy fuel oil contamination, Ventilrotation gestört, Verzögerter Sitz-Nachschliff

Preventive: Regelmäßiger Ventilsitz-Nachschliff, Rotocap-Prüfung, Brennstoffqualitätskontrolle

Liner wear

Symptoms: Erhöhter Schmierölverbrauch, Blow-by, Kompressionsverlust

Causes: Unzureichende Zylinderschmierung, Schlechte Brennstoffqualität (Kat-Fines), Ungünstige Betriebsbedingungen (häufiges Manövrieren)

Preventive: Zylinderschmierung optimieren, regelmäßige Laufbuchsenvermessung, Brennstoffreinigung sicherstellen

Expert tips

💡 The LSE variant is optimized for low fuel consumption — during inspections, document combustion parameters (Pmax, Pcomp, exhaust gas temperature) with particular care to detect deviations from eco-optimization early.
💡 At 430 mm bore, the range begins in which pistons and liners can still be handled with ship's own equipment — check on-board lifting equipment and tools for completeness and certification.
💡 Camshaft chain drive on UEC engines often has longer overhaul intervals than on MAN MC — nevertheless document chain elongation regularly.

Related components

Turbolader Ladeluftkühler Crosshead bearing and guide Main bearing and crankshaft Pleuellager Camshaft and chain drive Einspritzpumpen Torsionsschwingungsdämpfer Brennstoffaufbereitung Starting air system and starting valves

Classification & regulatory

IACS UR Z10 for class surveys observe. NOx Technical File and EIAPP certificate verify. Torsional vibration analysis for 5-cylinder engine verify in class certificate. MARPOL Annex VI compliance ensure.

Reference content for inspector orientation. Always verify against manufacturer's manual, latest service letters and class society requirements.