Cylinder liner for Mercedes-Benz OM421

The cylinder liner, part number 89390110, is a component for the Mercedes-Benz OM421 engine. This cylindrical sleeve inserts into the engine block to provide the sliding surface for the piston and rings, effectively forming the combustion chamber. It is manufactured by Mercedes-Benz to meet the specific dimensional requirements of this engine series.

A cylinder liner provides a controlled surface for the piston to travel against while maintaining the seal necessary for compression. It acts as a thermal bridge, transferring heat from the piston and combustion gases into the engine block cooling system. By maintaining precise internal diameters, the liner ensures that the piston and rings operate within specified tolerances, which is necessary for the efficient operation of the engine.