Influence of Piston Slap on Engine Block Vibration

Influence of piston skirt clearance on engine noise has been presented in this paper. Traces of forces producing engine block vibrations, i.e. gas force, and piston slap force were estimated and verified with real sampled data. An engine block vibration signal decomposition was also carried on, what enabled the identification of the influence of piston clearance on wavelet factor values C(a,b). It has been proved that increasing piston skirt clearance, delays the response of engine body on piston slap.