Dynamic Analysis and Experimental Evaluation of Variable Valve Lift System for Internal Combustion Engine with Double Overhead Camshaft

In modern four-stroke automobile engine technology, variable valve timing and lift control offer potential benefits for making a high performance engine. Variable valve lift (VVL) system for automotive engines is one of the key technologies to attain improvement of fuel economy, power output and reduction of emission. This paper describes an analytical simulation model of the VVL system. The VVL mechanism with a polynomial cam profile is designed to have maximum lift that is greater than the lift of the conventional mechanism. A dynamic model of VVL mechanism with three degrees of freedom is presented. The N42-BMW cylinder head with Valvetronic VVL of internal combustion engine was used in the test set-up. The motored cylinder head test data focuses on VVL system response and evaluation of the developed VVL mechanism. The performance results of a VVL for an overhead camshaft were investigated on the basis of theoretical simulation and experimental data to verify the validity of the VVL system in the test rig.