Maximizing the Torque Potential at Full Load of a 1.8 L Multivalve SI Engine

The main objective of the work which is presented is to optimize the breathing and torque in the whole operational speed range for multi-valve engines, without any variable system (valve timing or induction), by the application of both computational (modelling methodologies) and experimental (steady flow rig and engine test bench) means.

The study has been performed on a typical 1.8-litre multi-valve engine which developed a standard maximum torque of 146.5 Nm at 4500 rpm. After modification, the optimized performance was 161 Nm at 4250 rpm (an improvement of approximately 10%).