Wartsila L20 & L20C Cylinder Head

Wartsila L20 & L20C Cylinder Head for Marine Diesel Engines

The Wartsila L20 and L20C Cylinder head (alternatively termed cylinder cap) is an important component designed for heavy duty to handle high thermal and mechanical loads in medium speed marine diesel engines. This component was initially designed for operation on heavy fuel oil (HFO) and has highly optimised cooling water channels and strong valve seats for guaranteed gas tightness, fuel efficiency and extended overhaul intervals.

Equipped with the Wartsila 20 series for primary mechanical propulsion or crucial auxiliary power generation, uncompromising cylinder head integrity saves costly downtime and critical combustion leaks in your vessel. We provide high quality cylinder heads with internal components ready to be fitted, built to withstand the rigours of tough maritime operating environments.

Technical Specifications

Model & Part Number Cross-References

To facilitate accurate inventory mapping and ordering, these cylinder heads correspond to the following Manufacturer Part Numbers (MPN) and structural variants:

• Standard MPN / Item No: 120001 / 120005 / 120025
• Wartsila Engine Model Designations: 4L20, 5L20, 6L20, 8L20, 9L20
• Cross-Reference IDs: 10009352, WY120001, Reference: Wartsila-L20-120025

Compatibility

These cylinder heads are fully compatible with all inline configurations of the Wartsila 20 family, including fixed-speed auxiliary generating sets (gensets) and variable-speed mechanical propulsion configurations:

• Wartsila 4L20 / 4L20C
• Wartsila 6L20 / 6L20C
• Wartsila 8L20 / 8L20C
• Wartsila 9L20 / 9L20C
• Wartsila 20DF

Applications

1. Commercial Marine Gensets: Primary auxiliary power for container ships, VLCCs and bulk carriers.
2. Mechanical Main Propulsion: Small Cargo Vessels, Double Ended Coastal Ferries, Heavy Duty Harbour Tugs.
3. Stationary or dynamic positioning power arrays aboard PSVs, AHTS and wind-farm installation platforms Offshore Support Vessels
4. Decentralised small-scale land-based power plants: Stationary diesel and dual-fuel decentralised electricity systems.

Engineer’s Insights:

When installing an L20 or L20C cylinder cover, the most common mistake is uneven landing or improper hydraulic tensioning. The Wartsila 20 utilizes a 4-stud design requiring uniform pre-loading.

1. The Landing Check: Before setting the head on the liner, always verify that the flame-plate landing face and the landing ring surface are entirely free of carbon deposits. Even a 0.05mm speck of carbon will tilt the head slightly under torque, causing chronic exhaust gas blow-by and premature fire-ring failure.
2. Hydraulic Tensioning Care: Never rely on manual torque wrenches for final seating. Always apply the exact hydraulic tightening pressures mandated in Section 07 of the Wartsila instruction manual. Tighten crosswise in stages (e.g., 30%, 60%, 100% of final pressure) to guarantee uniform deformation across the cylinder liner’s anti-polishing ring.
3. Fuel Timing & Valve Seats: If you are operating on HFO, inspect your fuel valve sealing set (Part 167044) at every scheduled overhaul. A dripping or poorly atomizing injector tip rapidly elevates local exhaust temperatures, accelerating valve seat recession on the Nimonic exhaust valve spindles (Part 121001). Monitor your Exhaust Gas Temperature (EGT) deviations across all cylinders—if one cylinder spikes, check the injector before it burns the valve seat.