Significance of Burn Types, as Measured by Using the Spark Plugs as Ionization Probes, with Respect to the Hydrocarbon Emission Levels in S. I. Engines

A method has been developed for the acquisition and analysis of electrical signals, called combustion signals, from the cylinders of spark ignition engines based on using the spark plugs as ionization probes.A correlation has been established between the simultaneously recorded combustion and cylinder pressure signals based on which combustion signals could be used to identify three types of burns. These burn types were called good burns, slow burns, and misfires.The statistical occurrence of these burn types was also correlated with the hydrocarbon exhaust emission levels for engines operating under dynamometer simulated decelerations and for engines operating with various amounts of exhaust gas recirculation (EGR). Both production.