Detailed Valvetrain Models

Abstract

Valve control is critical to the performance of high speed racing engines. Even slight errors in valve timing can lead to significant power loss and deviations from the design valve motion may affect engine life. Traditionally, valve-train designs have been optimised using simple rigid body models. At high loads, however, component flexibility leads to discrepancies between predicted and measured results. These can arise either from within each single valvetrain or from torsional effects in the full engine system. This paper describes how full engine system and detailed single valvetrain models have been used in the process of developing a high-speed racing engine. Results from the models have shown how valvetrain dynamics is affected by component flexibility and have given solutions to durability problems.