Abstract
It is thought that the innovation of ignition system becomes more important toward the relization of ultra-lean combustion for gasoline engine. In this study, High Speed plasma Ignition as the new ignition system for internal combustion engine was investigated. The high speed plasma is non-thermal plasma formed by impression of a high voltage with ultra-short duration between coaxial cylindrical electrodes. As the result of varification experiment by using a single cylinder engine, a volumetric ignition with low energy consumption was realized. Also, an improvement of ignitability in comparison with a conventional spark plug was confirmed.