PISTON MOVEMENT AND ITS INFLUENCE ON NOISE OF AUTOMOTIVE ENGINES

This paper compares the calculated and measured piston transverse movement in a spark ignition engine. The induction of engine vibrations by the piston slap is studied by measuring the lateral forces at the piston skirt during the impact on the cylinder. The application of a piston movement computer program for piston development is demonstrated in the case of engine noise due to piston top land slap. The pressure differences in the main combustion chamber of an IDI-diesel engine are measured, and the effect on the piston attitude is analysed. Examples of low-noise piston design for diesel engines are presented.