Filho, F., Teixeira, A., Baêta, J., Guzzo, M. et al., "Stratified Torch Ignition Engine: Raw Emissions," SAE Technical Paper 2016-36-0477, 2016, doi:10.4271/2016-36-0477.
A global effort has been made by the scientific community to promote significant reduction in vehicle engine out-emission. To comply with this goal a stratified torch ignition (STI) engine is built from a commercial existing baseline engine. In this system, combustion starts in a pre-combustion chamber, where the pressure increase pushes the combustion jet flames through calibrated nozzles to be precisely targeted into the main chamber. These combustion jet flames are endowed with high thermal and kinetic energy, being able to generate a stable lean combustion process. The high kinetic and thermal energy of the combustion jet flame results from the load stratification. The engine out-emissions of CO, HC and CO2 of the STI engine are presented, analyzed and compared with the baseline engine. The STI engine showed a significant decrease in the specific emissions of CO and CO2. On the other hand, HC specific emission increased due to wall wetting from the fuel hitting in the precombustion chamber wall.