6UEC45LA
The Mitsubishi 6UEC45LA is a medium-speed, two‑stroke diesel main engine delivering up to 5 610 kW at 167 rpm, designed for bulk carriers and tankers with a focus on fuel efficiency and IMO Tier II compliance.
Engine Specifications
Inspector Detail
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Designation decoded
6 = Anzahl der Zylinder (6-Zylinder-Reihenmotor), UEC = Unified Exhaust-port Crosshead (Zweitakt-Kreuzkopfmotor-Baureihe von Mitsubishi), 45 = Zylinderbohrung in cm (450 mm), LA = Long-stroke Advanced (langhubige, weiterentwickelte Ausführung)
Background
The 6UEC45LA is a 6-cylinder two-stroke crosshead engine with 450 mm bore and 1350 mm stroke, manufactured by Mitsubishi Heavy Industries / J-ENG. The LA design (Long-stroke Advanced) offers optimized combustion parameters with conventional camshaft control. With a mean effective pressure of 18.5 bar, the engine delivers high specific power and is used in medium-sized tankers and bulk carriers.
Calculated metrics
Inspector checklist
- Bore-Gauging zur Bestimmung des Verschleißprofils durchführen
- Inspect piston rings for wear, fracture and coating abrasion
- Inspect piston crown and piston skirt for thermal cracks and scoring marks
- Kreuzkopflager-Clearance messen
- Record crankshaft deflection and compare with reference values
- Check connecting rod bolt elongation and preload
- Document camshaft profile wear and pitting
- Check valve timing and compare with manufacturer specifications
- Chain drive: check chain elongation, chain wheel clearance and tensioner
- Inspect valve seat and spindle for burnout and corrosion
- Rotocap-Funktion verifizieren
- Measure valve lift and guide clearance
- Fuel injectors: check opening pressure, spray pattern and sealing
- Fuel pump timing and delivery rate check
- Hochdruckleitungen auf Ermüdungsrisse untersuchen
- Cylinder oil feed rate adjust according to operating conditions and BN value
- Kolbenkühlöl-Temperaturdifferenz überwachen
- Hauptlager-Ölversorgungsdruck verifizieren
Logbook reference values
| Parameter | Expected | Deviation means |
|---|---|---|
| Abgastemperatur je Zylinder | 320–380 °C at rated load | Deviations indicate combustion disturbances, injection problems or charge air losses |
| Max. Zünddruck (Pmax) | Gemäß Herstellerangabe ± 5 bar | Lower Pmax indicates compression loss or injection timing error |
| Mittlerer effektiver Druck (MEP) | ~18.5 bar at full load | Deviations show power loss due to mechanical or thermal problems |
| Spülluftdruck | 1,8–3,0 bar (lastabhängig) | Zu niedriger Wert weist auf Turbolader-Degradation hin |
| Kühlwasseraustrittstemperatur | 80–85 °C | Elevated values indicate cooling system fouling or thermostat failure |
| Zylinderöl-Verbrauch | 0,5–1,0 g/kWh | Increased consumption signals wear on cylinder liner or rings |
| Kolbenkühlöl-Austrittstemperatur | 45–55 °C | Zu hohe Werte weisen auf Verkokung in Kolbenkühlräumen hin |
Common Failure Modes
Expert tips
- 💡 At 18.5 bar MEP the engine operates close to its thermal load limit – monitor piston cooling oil temperatures and exhaust gas values closely.
- 💡 The LA design has optimised exhaust port geometry – after cylinder liner replacement, absolutely ensure correct installation position of the liner (port timing).
- 💡 Bei UEC-Motoren mit konventioneller Nockenwelle die Fuel-Cam-Profilmessung in das reguläre Inspektionsprogramm aufnehmen.
Related components
Classification & regulatory
Compliance with MARPOL Annex VI and NOx Tier II limit values must be ensured. Consult EIAPP certificate and NOx Technical File during overhaul of NOx-relevant components (fuel injectors, camshaft, valve timing). When operating in ECAs check fuel changeover and SOx compliance.
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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