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Mitsubishi
8UEC52LA
The Mitsubishi 8UEC52LA is an eight‑cylinder, low‑speed two‑stroke main engine delivering about 16 400 kW at 124 rpm, designed for large commercial vessels and notable for its electronic control of fuel injection and exhaust valves.
16400.0 kW
Power
Engine Specifications
8
Cylinders
520 mm
Bore
1600 mm
Stroke
16,400 kW
MCR Power
124.0 rpm
MCR RPM
2-stroke
Stroke Type
Family: Mitsubishi UEC (LS/LA/LSE/LSII)
· Tier: IMO Tier II
· Fuel: HFO, MDO
Inspector Detail
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Designation decoded
8UEC52LA – Mitsubishi 8-Zylinder, Unified Exhaust-valve Crosshead, 520 mm Bohrung, Langhub, A-Ausführung (LA). Zweitakt-Kreuzkopfmotor der LA-Baureihe.
Background
The UEC52LA is a slow-speed two-stroke crosshead engine with 520 mm bore and 1,600 mm stroke from Mitsubishi's LA series. The LA series is an earlier design line with proven reliability. With 8 cylinders, the engine offers optimum mass balance and is suitable for medium-sized bulk carriers and tankers.
Calculated metrics
Stroke To Bore Ratio
3.08
Inspector checklist
Cylinder liner and piston
- Measure liner wear and ovality
- Check piston rings for wear, breakage and carbon buildup
- Inspect piston crown for cracks and erosion
- Spülschlitzzustand dokumentieren
Auslassventil
- Check valve seat and valve plate for erosion and corrosion
- Measure valve guide for wear
- Test hydraulic drive for leakage and function
Engine and bearings
- Measure and record crankshaft deflection
- Check crosshead and connecting rod bearing clearance
- Hauptlagerdeckel-Schrauben auf Vorspannung prüfen
Kraftstoffsystem
- Check fuel injection pumps and nozzles for wear
- Kraftstoff-Hochdruckrohre auf Ermüdungsrisse inspizieren
- Überströmventile auf korrekte Einstellung testen
Scavenge air system and turbocharger
- Check turbocharger impeller for imbalance and contamination
- Test scavenge air cooler for leakage and contamination
- Wasserabscheider-Funktion kontrollieren
Logbook reference values
| Parameter | Expected | Deviation means |
|---|---|---|
| Exhaust gas temperature per cylinder | 340–420 °C | Zylinderweise Abweichung >30 °C zeigt Verbrennungsstörung an |
| Pmax-Differenz zwischen Zylindern | ±3 bar | Größere Streuung erfordert Einspritztiming-Korrektur |
| Scavenge air temperature after cooler | 35–50 °C | Erhöhte Temperatur deutet auf Kühlerverschmutzung hin |
| Kühlwasser-Austrittstemperatur | 75–85 °C | Exceedance indicates deposits or flow problems |
| Schmieröltemperatur vor Motor | 40–47 °C | Elevated temperature may indicate cooler problems or bearing damage |
Common Failure Modes
Laufbuchsenverschleiß (ungleichmäßig)
Symptoms: ['Erhöhter Zylinderölverbrauch', 'Blow-by-Geräusche', 'Verschlechterte Kompression']
Causes: Insufficient or incorrectly adjusted cylinder lubrication, Kraftstoffqualität (hoher Schwefel/Aschen-Gehalt), Thermische Überlastung
Preventive: Zylinderschmierung gemäß Hersteller einstellen; regelmäßige Laufbuchsenvermessung; Kraftstoffaufbereitung sicherstellen
Kreuzkopflager-Überhitzung
Symptoms: ['Temperaturanstieg am Kreuzkopf', 'Metallpartikel im Schmieröl', 'Klopfgeräusche']
Causes: Fluchtungsfehler, Ölverunreinigung, Überlastung
Preventive: Monitor lubricating oil quality and supply; take deflection measurements at regular intervals; observe operating limits
Turbocharger bearing damage
Symptoms: ['Erhöhte Vibration', 'Reduzierter Ladedruck', 'Abnormale Geräusche']
Causes: Verschmutzung der Schmierstellen, Surging due to part-load operation, Alterung der Lagerbauteile
Preventive: Turbocharger maintenance according to manufacturer's interval; cleaning of compressor and turbine; perform vibration measurement regularly
Expert tips
- 💡 Die LA-Baureihe ist eine bewährte, aber ältere Konstruktion – Ersatzteilversorgung frühzeitig mit Mitsubishi klären, da einige Komponenten möglicherweise abgekündigt sind.
- 💡 Bei der 520-mm-Bohrung auf korrekte Kolbenring-Spezifikation achten – Verwechslung mit 500-mm-Ringen der UEC50-Serie vermeiden.
- 💡 8-cylinder configuration shows best vibration characteristics – if vibration irregularities occur, first check torsion damper and propeller condition.
Related components
Torsionsschwingungsdämpfer
Anlassluftventile
Control cams and roller tappets
Kolbenkühlöl-Versorgung
Zylinderschmierölpumpen
Hauptlager-Thermometer
Classification & regulatory
Older LA series is subject, depending on year of manufacture, to possible IMO Tier I requirements. NOx Technical File to be presented at class surveys. MARPOL Annex VI compliance for SOx emissions to be ensured. Consult classification society for engine modifications.
Reference content for inspector orientation. Always verify against manufacturer's manual, latest service letters and class society requirements.
Other Cylinder Configurations 44
5UEC33LSE
5 cyl
· 3,100 kW
5UEC37LA
5 cyl
· 4,250 kW
5UEC43LSE
5 cyl
· 6,000 kW
5UEC45LA
5 cyl
· 7,000 kW
5UEC50LSE
5 cyl
· 9,250 kW
5UEC50LSII
5 cyl
· 9,500 kW
5UEC52LA
5 cyl
· 10,250 kW
5UEC60LS
5 cyl
· 14,500 kW
5UEC60LSII
5 cyl
· 15,250 kW
5UEC68LSE
5 cyl
· 19,500 kW
5UEC68LSII
5 cyl
· 20,250 kW
5UEC85LSII
5 cyl
· 29,000 kW
6UEC33LSE
6 cyl
· 2,100 kW
6UEC37LA
6 cyl
· 5,100 kW
6UEC43LSE
6 cyl
· 7,200 kW
6UEC45LA
6 cyl
· 5,610 kW
6UEC50LSE
6 cyl
· 7,320 kW
6UEC50LSII
6 cyl
· 11,400 kW
6UEC52LA
6 cyl
· 12,300 kW
6UEC60LS
6 cyl
· 17,400 kW
6UEC60LSII
6 cyl
· 18,300 kW
6UEC68LSE
6 cyl
· 23,400 kW
6UEC68LSII
6 cyl
· 24,300 kW
6UEC85LSII
6 cyl
· 22,680 kW
7UEC33LSE
7 cyl
· 4,340 kW
7UEC37LA
7 cyl
· 5,950 kW
7UEC43LSE
7 cyl
· 8,400 kW
7UEC45LA
7 cyl
· 9,800 kW
7UEC50LSE
7 cyl
· 12,950 kW
7UEC50LSII
7 cyl
· 13,300 kW
7UEC52LA
7 cyl
· 14,350 kW
7UEC60LS
7 cyl
· 14,420 kW
7UEC60LSII
7 cyl
· 21,350 kW
7UEC68LSE
7 cyl
· 27,300 kW
7UEC68LSII
7 cyl
· 28,350 kW
7UEC85LSII
7 cyl
· 40,600 kW
8UEC33LSE
8 cyl
· 4,960 kW
8UEC43LSE
8 cyl
· 9,600 kW
8UEC45LA
8 cyl
· 11,200 kW
8UEC50LSE
8 cyl
· 14,800 kW
8UEC50LSII
8 cyl
· 15,200 kW
8UEC60LSII
8 cyl
· 24,400 kW
8UEC68LSII
8 cyl
· 32,400 kW
8UEC85LSII
8 cyl
· 46,400 kW
Components & Design
Component data being added…
Technical Data
SFOC (UEC60LSE-Eco-A2)
164-170 g/kWh (IMO Tier II)
BMEP (UEC60LSE)
20.0-21.0 bar @ MCR
Piston speed (UEC60LSE)
8.4 m/s
Dry mass UEC60LSE 8-cyl
447 tons
Dry mass UEC60LSE 5-cyl
300 tons
Bore/Stroke ratio UEC60LSE
4.00
Stroke/Bore UEC68LSE
3.96
Electronically controlled
Fuel injection, exhaust valve, cylinder lubrication (ECL)
unified from engine model
True
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Common failures & inspection points
Exhaust valve fouling due to sodium/vanadium deposits (Na2SO4, CaSO4, V2O5) with heavy fuel oil containing high sulphur content (up to 5%); below dew point conden
Turbocharger fouling due to coal and ash particles in exhaust gas during low-load operation, BMEP decline and combustion deterioration
Piston ring leakage and fuel dilution (>2-3%) due to wear on cylinder running surface/piston rings, increased blowby and oil contamination
Cylinder liner wear due to corrosive combustion with sulphurous fuel oil; inspection criterion: wear according to height of sliding surface, max. permissible
Main bearing wear due to oil contamination; weekly inspection for water ingress (<2% permissible) and 3-month analysis for wear metals (Fe, Cu) required
Type-general inspection and maintenance points for this equipment category — not model-specific.
Suppliers & Spare Parts
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Equipment Model #38613
· ✓ still in production