MAN B&W

This service letter gives important information regarding development of fretting/corrosion on main bearing caps. In service, we occasionally observe fretting/corrosion between the main bearing shell and the main bearing cap on engines without main bearing temperature sensors.

This service letter contains important information about the development of fretting marks at the assembly surfaces of the connecting rod and the marine head, and possible rework of this. The complete connecting rod consists of three different parts, upper and lower marine head parts and the connecting rod. Due to the operation forces the connections of these parts are exposed to the development of fretting that may occur over time.

The high reliability of MAN B&W engines is of key importance to MAN Diesel & Turbo, and we have therefore decided to terminate the reconditioning programme for the MPC and MPC-10.

For the engine type L16/24 we have learned that the lifetime of the fuel injection nozzle can be extended considerably by lowering the opening pressure from 450 bars to 400 bars. Based on our findings, we have
updated  our  attached  description:  Data  for  Pressure  and  Tolerance 500.35.

The latest ISO marine fuel standard specifies levels of up to maximum 60 ppm Al + Si in the fuel (ISO 8217). Such a level would cause high wear compromising reliability in the combustion chamber, and so the fuel
must be cleaned on board the ship before it reaches the engine.

This Service Letter specifies the recommended maximum acceptable level of cat fines entering the engine, which is as follows:
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Always keep the level as low as possible and, max. at 15 ppm
Al + Si at engine inlet for short periods.

Based on the latest service experience and engine development we are pleased to issue a revised version of the Guiding Overhaul Intervals tables. The guiding overhaul intervals apply to electronically controlled ME type engines, dual fuel ME-GI type engines, and mechanically controlled MC types engines.

This paper describes in detail the service experience of the new generation of super-long stroke S and G Mk 9 type engines. Focus will be on the cylinder condition in general and cold corrosion control in particular.