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The water guide jacket, code P50507-03, plays a vital role in the thermal management of the MAN L21/31 engine by channeling coolant around critical engine components, such as the cylinder liners and combustion chamber. It ensures even heat distribution, prevents hotspots, and supports optimal engine temperature during operation. Constructed from corrosion-resistant materials, the jacket helps extend the life of internal parts and safeguards the engine against overheating, making it indispensable for sustained high-performance use at sea or in power plant conditions.

The valve spindles and valve gear assembly, code P50502-18, are essential for the timed control of gas exchange within the MAN L21/31 engine. This system regulates the opening and closing of intake and exhaust valves, ensuring precise airflow and exhaust management during each engine cycle. Made of high-strength alloys and engineered for minimal wear, these components operate under heavy mechanical and thermal loads. Their performance is crucial for efficient combustion, fuel economy, and long-term engine reliability in demanding operational environments.

Monday, 10 November 2025 12:24

MAN L21/31; Cylinder Head (Code P50501-27)

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The cylinder head, code P50501-27, is one of the most critical components in the MAN L21/31 engine, forming the upper seal of the combustion chamber. It houses the intake and exhaust valves, fuel injectors, and part of the cooling and lubrication circuits. Designed for high durability and thermal stability, the cylinder head must endure extreme temperatures and pressures during continuous engine operation. Its precise machining and structural integrity are key to maintaining efficient combustion, proper sealing, and overall engine performance in both marine and power generation applications.

The bolt marked K 28034 is a specially engineered fastener designed for securing the main rocker arm (K 28005) in the ZV40/48 engine. This bolt must withstand dynamic mechanical loads, thermal fluctuations, and vibrations encountered during valve operation. Manufactured from high-strength alloy steel and precision-machined for perfect fit and tension, it plays a vital role in ensuring stable rocker arm performance. Its reliability is crucial for maintaining accurate valve timing and reducing mechanical stress on the valvetrain.

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