Development of Low Emission High Performance Four Valve Engines

Research and development activities on high-performance S.I. engines for passenger car application are mainly concentrated on full load performance development as well as the development of combustion systems and engine structures in order to meet future market and legislation requirements.

This paper presents results out of AVL's R&D work in the field of multi-valve S.I. engines. Variable Intake Systems of different design are compared to Variable Valve Timing devices with respect to overall engine performance. Engine and vehicle test results of a four-valve engine with the AVL developed C̱ontrolled Ḇurn Ṟate (CBR) combustion system are presented and analyzed. The control of charge stratification, charge motion and hence of the combustion pattern turns out as a major requirement for the investigated advanced combustion systems.