Individual-Cylinder Knock Occurence and Intensity in Multicylinder Engines

To increase our understanding of engine knock, the cycle-to-cycle variations of knock occurrence and knock intensity in and among the individual cylinders of two multicylinder production engines run at steady speeds have been investigated. Statistical analyses, including autocorrelation analysis and cross correlation analysis between cylinders, showed that knock occurrence and intensity are random and depend solely on the conditions of each individual firing cycle. Individual cylinder knock occurrence and intensity correlated with cylinder pressure development.