Chaotic Combustion in Spark Ignition Engines
  We analyse the combustion process in a spark ignition engine using the experimental data of an internal pressure during the combustion process and show that the system can be driven to chaotic behaviour. Our conclusion is based on the observation of unperiodicity in the time series, suitable stroboscopic maps and a complex structure of a reconstructed strange attractor. This analysis can explain that in some circumstances the level of noise in spark ignition engines increases considerably due to nonlinear dynamics of a combustion process. 
M. Wendeker, J. Czarnigowski, G. Litak, K. Szabelski (Technical   University of Lublin)