6UEC33LSE

Designation decoded

{'6': 'Zylinderanzahl: 6 Zylinder', 'UEC': 'Unified Exhaust-port Crosshead – Mitsubishi Zweitakt-Kreuzkopfmotor mit Auslassschlitzen', '33': 'Zylinderbohrung: 330 mm', 'LSE': 'Long Stroke Eco – economical long-stroke engine type with focus on fuel efficiency and reduced emissions'}

Background

The 6UEC33LSE is a 6-cylinder two-stroke crosshead engine with 330 mm bore and 1050 mm stroke of the LSE series. As the smallest engine in this series with a known MEP of 17.5 bar, it is designed for small merchant vessels, coastal shipping and smaller bulk carriers. The 6-cylinder configuration offers significantly lower torsional vibration risks compared to 5-cylinder engines.

Calculated metrics

Inspector checklist

Logbook reference values

Common Failure Modes

Expert tips

• 💡 The 6UEC33LSE at 17.5 bar MEP operates at the upper loading limit – pay particular attention to signs of thermal overload on the piston crown and exhaust valve.
• 💡 6-cylinder configuration offers significantly better mass balance and torsional characteristics than 5-cylinder – vibration problems are rare, but not excluded.
• 💡 Smallest bore of the UEC series: components are easier to handle, but specific loading per unit area is high due to the high MEP – wear rates can be surprising.

Related components

Classification & regulatory

6-cylinder engine with more favourable vibration characteristics than 5-cylinder – simplified torsional documentation in accordance with IACS UR M68 possible. LSE variant: verify validity of EIAPP certificate and NOx Technical File. At MEP of 17.5 bar, operating limits are tight – strictly observe performance curves and limit values from the operating manual. Document compliance with IMO NOx Tier II/III depending on year of construction and area of operation.