Wear profile of the cylinder liner in a motor truck diesel engine

The paper presents results of investigation of cylinder liners wear. The investigation was carried out on diesel engines during long lasting operation in 5 motor trucks. Cylinder diameters were measured in two perpendicular planes on four depths using 2-point bore gauge, after removal of the cylinder head. Measurements were made every 50 000 km of vehicle mileage. Such methodology of measurements enabled to determine time course and wear profile of the cylinder liners (wear value in relation to the direction and height of the liner). It was stated that increments of diameter during the first period of operation are several times higher than during the later periods, when the wear intensity is constant. It was also found that wear of the cylinder liner in the plane perpendicular to the engine axis is bigger than in the parallel plane, and that wear in the upper part of the liner is twice as big as in its middle part. Measurement scheme for the cylinder liner; histogram of cylinder liner diameters obtained in measurements after the technological running-in of the engine after mileage of 0, 50,000 km, 150,000 km and 250,000 km, wear profiles of cylinder liners in the two directions at different vehicle mileages are presented in the paper. Estimated profiles of the cylinder liner wear will be used as input data for the calculations of the blowby intensity with the use of mathematical model of PRC set