⚓ Working on this equipment?
Ask the AI troubleshooter, log your hours on board and turn them into invoice-ready service reports — for this exact model.
Start free — 14 days →
No credit card required
🔧 65 verified suppliers & service companies for Wärtsilä in the Maritime Network
Find suppliers →
Wärtsilä
Wärtsilä 12VW34SG
The Wärtsilä 12VW34SG is a 12‑cylinder V‑type spark‑ignited marine gas engine delivering up to 8 MW (8000 kW) at 750 rpm, designed for low‑emission main propulsion or high‑power auxiliary generation using natural gas, biogas or hydrogen blends.
5760.0 kW
Power
Engine Specifications
12
Cylinders
340 mm
Bore
400 mm
Stroke
Components & Design
Component data being added…
Technical Data
Power per cylinder (main engine 34DF)
500 kW @ 750 rpm
Power per cylinder (auxiliary 34DF)
520 kW @ 720-750 rpm
Mean effective pressure (main)
20.0-19.8 bar
Piston speed
9.6-10.0 m/s
Compression ratio (16V/20V)
12.6:1
Engine type
4-stroke, turbocharged intercooled non-reversible
Swept volume per cylinder
36.3 dm³
34DF Max output (16V main)
8000 kW
34DF/34SG Max output (20V genset)
9800 kW
34SG design
Spark-ignited, lean-burn, pre-chamber
20V34SG dimensions
L:12.7m × W:3.3m × H:4.65m
20V34SG weight
131,500 kg
configuration
V
rpm
750
fuel type
Natural Gas
technology
Spark-Ignited Gas (SG)
displacement l per cyl
36.3
🤖 Ask about this model
One free question — answered like a marine engineer. No account needed.
Common failures & inspection points
Turbocharger bearing failure - bearing location pins can break, causing the shaft to rotate freely inside housing and potentially damaging the compressor wheel.
Fuel injector tip carbon deposits and clogging - when operating in backup fuel (diesel) mode, liquid fuel deposits on injector tip can thermally decompose ('cra
Gas valve unit (GVU) functionality criticality - GVU valve tightness and proper ventilation during stop sequences essential for safe operation; leakage prevents
Cylinder liner scuffing from insufficient lubrication - mirror polished finish and loss of crosshatch pattern indicate oil starvation; piston rings run dry caus
Load-sharing failures and abnormal shutdown sequences - improper sensor signals or fuel supply irregularities can trigger emergency stops; root causes (fuel sys
Type-general inspection and maintenance points for this equipment category — not model-specific.
Suppliers & Spare Parts
Direct links to manufacturer, datasheet, spare-parts portal and dealers — request access below.
📄 Request sourcing links & documents🛠 Manage this equipment in your fleet
Cases, daily reports, timesheets and AI troubleshooting in the OceanSphere Marine app — free for 14 days.
Start free trial →🔎 Suppliers & service for this equipment
Find manufacturers, repair shops and spare-part dealers in the Maritime Network — our global company directory.
Maritime Network →Working on this unit?
Log hours, photos and findings into an invoice-ready service report — OceanSphere Marine, 14-day free trial.
Need a service partner for Wärtsilä?
114,000+ shipyards, suppliers and service companies in the Maritime Network directory.
Equipment Model #66611
· ✓ still in production