Abstract
In order to meet the future requirements of the legislative on the reduction of engines exhaust emissions together with the demands for lower fuel consumption, there are still important resources to improve the internal combustion engine performances, especially in the field of valve timing systems. Therefore, the research works directed toward the improvement of those systems means an actual and very interesting approach among engines manufacturers.
Research work carried out together by the authors revealed how some constructive and cinematic modifications into distributing system can influence the spark engines characteristics.
One of the conclusions of those experimental investigations stated that the rigid behavior of classic valve timing is a major inconvenience in the efficient applying of favorable influences of those modifications, especially in case of automotive engines.
Starting from that aspect and based on theoretical and experimental results concerning the air/fuel flowing processes through the inlet duct, the paper presents some conclusions of a new approach of the valve timing.