7G50ME-LGIM9.6
The MAN 7G50ME-LGIM9.6 is a low‑speed, 2‑stroke main engine delivering up to 21 700 kW at 127 rpm, featuring dual‑fuel capability with diesel pilot ignition and high‑pressure methanol injection for Tier III emissions compliance.
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Engine Specifications
Inspector Detail
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Designation decoded
7 = number of cylinders, G = Green Ultra Long Stroke, 50 = bore 500 mm, ME = MAN Electronically controlled, LGIM = Liquid Gas Injection Methanol, 9.6 = Mark 9.6 control generation.
Background
The G50ME-LGIM serves medium-sized ships: Handysize bulkers, small product tankers and feeder container ships up to 3,000 TEU. The G variant with a 2300 mm stroke (S/B=4.6) optimizes efficiency at low propeller speeds. 7 cylinders provide good mass balance.
Calculated metrics
Inspector checklist
- High-pressure pumps 600-700 bar: tightness, leak sensors
- Injection valves: 500 mm combustion chamber, spray pattern
- Double-wall piping: leak detection
- Diesel/methanol changeover: purge cycle
- Liners 500 mm: BN 25-40, wear rate
- Piston rings: bore polishing with clean combustion
- Crosshead: S/B=4.6, high side forces from the long stroke (2300 mm), LI shell impression
- Stuffing box: drainage monitoring
- HPS 300 bar: oil quality
- FIVA: methanol maps Mark 9.6
- Timing: ±0.5 degrees CA
- Methanol detectors
- ESD: automatic diesel
- UV/IR in the fuel prep room
- OMD: 7 cylinders
Logbook reference values
| Parameter | Expected | Deviation means |
|---|---|---|
| Exhaust temperature (methanol) | 275-355 °C | >20 °C spread: injector |
| Methanol injection pressure | 600-700 bar | Pump/filter |
| Cylinder oil consumption | 0.5-0.8 g/kWh | Dosing |
| OMD | <2.5% LEL | Leakage |
Common Failure Modes
Expert tips
- 💡 The G50 with S/B=4.6 has one of the highest ratios — crosshead inspection is especially important.
- 💡 On medium-sized ships: methanol bunkering infrastructure is often not yet available at smaller ports — diesel fallback capability must be available at all times.
- 💡 7 cylinders at 500 mm: a compact engine with good vibration behaviour — but check the torsional damper.
Related components
Classification & regulatory
IGF Code, LFPF notation. IMO Tier II without after-treatment.
Reference content for inspector orientation. Always verify against manufacturer's manual, latest service letters and class society requirements.
Other Cylinder Configurations 47
Components & Design
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Technical Data
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