Spark plug with the increased energy for creating of initial combustion centre

Variability of the working cycle of the internal combustion engines with the combustion of homogenous mixture is a long-term problem of SI engines. The paper shows a decrease of cycle variability and an increase of the engine efficiency by using a spark plug, whose design allows the ignition of the mixture in the same way as using a classical spark plug by the high-voltage discharge between electrodes of the spark plug and at the same time increases the energy for the development of mixture combustion in the initial phase by a flame jet from a very small ignition chamber. Energy of flame jet for the mixture ignition into compression volume at engine cylinder is fully 100 times higher to energy of high-voltage discharge on the spark plug. The laboratory results of experimental works on vehicle SI engine (the visual inspection of initial phase of burning, course of cylinder pressure, engine power data) are showed. On basis performed tests has been projected the new design of the spark plug with the integrated combustion chamber. According to our engineering design was made the new spark plug with the ignition chamber like functional samples in company BRISK. Proving test with this new spark plug was performed on two different test engines at Department research laboratory on Technical University of Liberec. The experiments confirm the await results: the engine characteristics has been significantly improved. New design of spark plug with integrated chamber it was registered at Bureau of industrial ownership at Prague.