5UEC50LSE
The Mitsubishi 5UEC50LSE is a medium-speed, 2‑stroke main propulsion engine delivering up to 9 250 kW at low rpm, noted for its high specific fuel consumption efficiency and flexible heavy‑fuel operation.
Engine Specifications
Inspector Detail
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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); 50 = cylinder bore in cm (500 mm); LSE = Long Stroke Eco (long stroke with ecological and economical optimization, reduced SFOC)
Background
The 5UEC50LSE is a medium-sized two-stroke crosshead engine of the UEC series with 500 mm bore in LSE configuration (Long Stroke Eco). The LSE version is optimized for low specific fuel oil consumption and reduced emissions and represents a further development of the LS base version. The engine is used for Panamax bulk carriers, MR tankers and larger general cargo vessels.
Calculated metrics
Inspector checklist
- Chain drive wear, chain elongation and chain tensioner inspection
- Inspect cam profiles for pitting and scoring
- Nockenwellenlager-Spiel kontrollieren
- Steuerzeiten mit Referenzwerten abgleichen
- Check fuel injection pumps for wear (plunger, bushing, pressure valve)
- Test fuel injection nozzles opening pressure, spray pattern and leakage
- High-pressure fuel lines for fatigue and cracks
- Control fuel pre-treatment and filtration grade
- Valve spindle and seat for hot corrosion and burnout
- Ventildrehvorrichtung Funktion prüfen
- Valve guide wear and clearance
- Valve actuation mechanism tightness and function
- Laufbuchsen-Verschleißmessung (500 mm Bohrung, mehrere Messpunkte)
- Piston rings end gap and radial pressure
- Piston crown thermal cracks and erosion
- Scavenge ports condition and freedom
- Crosshead bearing clearance and oil supply
- Piston rod surface and dimensional accuracy
- Stuffing box lamellae condition and scraper seal tightness
- Kurbelwellen-Durchbiegung dokumentieren
- Torsional vibration damper condition and silicone oil level
- Barred Speed Range signage at bridge and engine room
- Axial-Schwingungsdämpfer kontrollieren
Logbook reference values
| Parameter | Expected | Deviation means |
|---|---|---|
| Pmax (Zünddruck) | Gemäß Testbed-Protokoll, Spreizung < 3 bar | Irregularity indicates injection or compression problems |
| Exhaust gas temperature per cylinder | Gemäß Hersteller, Spreizung < 30°C | Elevated temperature shows combustion problems or valve damage |
| Pcomp (Kompressionsdruck) | Gemäß Shop-Test, Abweichung < 2 bar | Verlust deutet auf Undichtigkeiten (Ringe, Ventil, Laufbuchse) hin |
| Zylinderschmieröl-Feedrate | 0.7–1.2 g/kWh | Incorrect dosage leads to wear or coking |
| Kühlwassertemperatur Zylinderauslass | 75–85°C | Deviation indicates cooling system or cylinder liner problems |
| Turbolader-Drehzahl | According to manufacturer specification at operating load | Deviation indicates turbocharger contamination or bearing wear |
| Kurbelwellen-Durchbiegung | Gemäß Hersteller-Limits (typisch ±0.05 mm) | Exceedance indicates bearing or foundation problems |
Common Failure Modes
Expert tips
- 💡 At 500 mm bore, the LSE version is trimmed for efficiency — detect and correct deviations in Pmax and exhaust temperature versus testbed values early to retain the SFOC advantage.
- 💡 At 5-cylinder engines with 500 mm bore, check foundation bolts and chocking regularly — vibration forces are significant at this cylinder count.
- 💡 Spare parts and technical support available since 2018 via J-ENG — for older units, confirm compatibility of new components with the existing engine version.
Related components
Classification & regulatory
Comply with IACS UR Z10 class surveys for two-stroke crosshead engines. Check NOx Technical File and EIAPP certificate. Verify torsional vibration analysis in class certificate for 5-cylinder. Observe MARPOL Annex VI compliance and ECA regulations.
Reference content for inspector orientation. Always verify against manufacturer's manual, latest service letters and class society requirements.
Other Cylinder Configurations 44
Components & Design
Component data being added…
Technical Data
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Common failures & inspection points
Borescope inspection of exhaust valve seats for scratches/wear, dye penetrant test for cracks, leakage measurements (valve should hold pressure under compressed air for 15 min)
Liner surface inspection for scratches/grooves, piston run gemietlich measurement, lubricant flow rate check (wrong parameters for part load operation)
Measure pressure drop across cooler, check air temperature after cooler, inspect drainage separator for water accumulation
Tägliche Kurbelgehäuse-Ölprobe auf Weißmetall-Partikel (>0.5 mm mit glatter Oberfläche beidseitig = Überbelastung), Lagerspiel-Kontrolle per Schieblehre
Check crankshaft bearing flanges with magnifying glass for cracks; crankshaft deflection measurement via dial gauge (indicator set: <0.1 mm critical)
Type-general inspection and maintenance points for this equipment category — not model-specific.
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