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Wärtsilä
6LW31SG
The Wärtsilä 6LW31SG is a six‑cylinder, 4‑stroke trunk piston main engine designed for spark‑ignited LNG operation, delivering about 1 800 kW at 750 rpm.
1800.0 kW
Power
Engine Specifications
6
Cylinders
310 mm
Bore
430 mm
Stroke
4-stroke
Stroke Type
Components & Design
Component data being added…
Technical Data
Cylinder power
610 kW/cyl (diesel)
Mean effective pressure (BMEP)
30 bar
SFOC (diesel)
167.7 g/kWh (optimal point)
Weight (8V31)
~57.1 tonnes (dry, diesel)
Weight (16V31)
~89–92.5 tonnes (dry, diesel)
Piston speed
10.75 m/s
Turbocharging
Two-stage turbocharging with intercooling
Fuel injection
Common rail direct injection
Valve layout
2 inlet, 2 exhaust valves per cylinder
power kw
1800
rpm
750
fuel type
LNG (Spark-Ignited)
configuration
L
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Common failures & inspection points
Low-load operation: Poor combustion, carbon deposit accumulation in cylinders, turbocharger fouling, economizer fouling. Wärtsilä offers Slow Steaming Upgrade K
Cylinder liner wear and scuffing (general 4-stroke diesel pattern, not W31-specific): Exacerbated by inadequate lubrication oil film, excessive cylinder tempera
Fuel injection system: Common rail system generally robust; however, HP fuel pump overhaul intervals are extended to 24,000 hrs (vs. 12,000 in prior-gen engines
Scavenge space deposit accumulation and fire risk (class-wide diesel phenomenon): Carbonized lube oil and unburnt fuel residues accumulate in scavenge space. Ex
Type-general inspection and maintenance points for this equipment category — not model-specific.
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Equipment Model #124307
· ✓ still in production