Spare Parts Guide 10 December 2025 9 min read

Sulzer RTA Spare Parts: Complete Guide for Ship Engineers & Operators

The Sulzer RTA series of two-stroke, low-speed marine diesel engines powers many of the world's largest bulk carriers, tankers, and container vessels. Now part of the Wärtsilä family (following Wärtsilä's acquisition of New Sulzer Diesel), these engines are designed for continuous, reliable operation over tens of thousands of hours.

Key Sulzer RTA Engine Models

Sulzer RTA48T — Popular medium-bore engine for handymax and panamax vessels

Sulzer RTA52U — Common on larger bulk carriers and product tankers

Sulzer RTA58T — Higher power output for VLCC and large cargo vessels

Sulzer RTA62U / RTA68 — Large bore engines for VLCCs and ULCCs

Sulzer RTA84C / RTA84T — Ultra-large bore for the biggest container ships and ore carriers

Essential Spare Parts for Sulzer RTA Engines

**Cylinder Components:**

Cylinder liner (cast iron, chrome-plated bore in upper area)

Piston crown (steel, with ring grooves)

Piston rod

Piston rings (cast iron, chrome-faced top ring)

Cylinder cover (head) complete

Cylinder cover O-rings and sealing rings

**Exhaust Valve:**

Exhaust valve spindle (Nimonic alloy)

Exhaust valve seat

Exhaust valve housing

Exhaust valve actuator components (pneumatic/hydraulic depending on variant)

Valve rotator

**Fuel System:**

Fuel injection valve (injector) complete

Fuel valve nozzle tip

Fuel pump plunger and barrel assembly

Fuel pump suction and delivery valves

High-pressure fuel pipe

**Starting System:**

Starting air valve (one per cylinder)

Starting air distributor

**Bearings:**

Main bearing shells

Crosshead bearing shells

Crankpin bearing shells

Thrust bearing segments

**Turbocharger (ABB/MAN fitted):**

Turbocharger cartridge or rotor

Nozzle ring

Bearing kit

Labyrinth seal kit

Maintenance Intervals for Sulzer RTA Engines

| Component | Inspection/Replacement Interval |

|---|---|

| Fuel injection valves | 1,000–2,000 hours |

| Exhaust valve spindle | 16,000–24,000 hours |

| Piston rings | 8,000–16,000 hours |

| Cylinder liners | 32,000–48,000 hours (condition-based) |

| Piston overhaul | 16,000–24,000 hours |

| Main bearings | Condition-based / survey interval |

| Turbocharger overhaul | 16,000–24,000 hours |

Special Considerations for Two-Stroke Engines

Sulzer RTA engines operate on a fundamentally different principle from four-stroke engines. Key considerations:

Cylinder lubrication — Separate lube oil injection to cylinder liners is critical. Monitor cylinder oil consumption and liner condition closely.

Scavenge air system — Keep scavenge ports clean and inspect for crankcase oil contamination.

Exhaust valve timing — Precise timing is critical for performance and emissions compliance.

Turbocharger matching — On modern engines, turbocharger condition directly affects fuel efficiency and CII ratings.

Sourcing Sulzer RTA Parts

Genuine Sulzer spare parts are now distributed through Wärtsilä's service network. MarineLink Solutions has established supply channels for both genuine Wärtsilä/Sulzer parts and certified OEM-equivalent alternatives.

With 20+ years of experience supplying low-speed engine components, we understand the critical tolerances involved in RTA spare parts. Contact us at sales@marinelinksolutions.com for competitive pricing and fast delivery on any Sulzer RTA component.