Variable Valve Actuation in Marine Leisure Diesel Engines

Abstract: Volvo Penta is a supplier of marine and industrial engines. To further develop the existing D4/D6 engines (3.7L 4-cyl and 5.5L 6-cyl marine leisure diesel engines) Volvo Penta wants to evaluate the possibility of adding a variable valve actuation (VVA) system to increase performance and improve efficiency. The objective for this study is to recommend a VVA system from the market for Volvo Penta D4/D6 engines for further development.The effects of different VVA strategies for diesel engines and the emission standards are described in the literature study.A research was performed to find VVA systems on the market. The research is summarized in the VVA system chapter. In this chapter the VVA systems working principles and the different valve lifts they can perform are explained.The VVA systems were evaluated in two steps. The first step was an evaluation matrix to compare different VVA systems. The evaluation matrix resulted in that three VVA systems were decided to be evaluated further. The second evaluation of the VVA systems was focused on which types of VVA strategies that can be used and which benefits they provide and the applicability in the engine architecture.The system that finally was recommended was Mechadyne VLD system with duration control on the intake valves. VLD is highly applicable in the D4/D6 engines and enables several VVA strategies that are suitable for diesel engines. VLD can be added to the exhaust valves for further development of VVA strategies.