Abstract
By the deactivation of one of the two intake ports of a four-valve engine the charge motion in the cylinder is increased and thereby the combustion accelerated and stabilized. On this way the dilution tolerance for exhaust gas is raised which effects in the case of high EGR-Rates a reduction in fuel consumption. To reach a solid operation with high EGR-Rates it is additional necessary to generate a stratified charge with an enriched mixture close to the spark plug at the ignition timing. Therefore the mixture preparation has to be adapted to the different operation conditions e.g. port activated or deactivated. To do this several development tools like video observation and 3D-CFD programs were used.
With this concept, the fuel consumption of a sub-compact class vehicle in the European drive cycle can be reduced by 3 to 6 per cent. Port Deactivation is a very simple possibility to increase the dilution tolerance for exhaust gas of four-valve engines without compromising the full load performance. The proven port fuel injection and the three-way-catalytic converter can be retained.