Advanced combustion and engine integration of a Hydraulic Valve Actuation system (camless)

An electro-hydraulic camless system has been installed on an EGR 11 litre multi-cylinder engine. This engine with fully flexible valve-train is therefore a powerful and efficient tool to study new combustion concepts in the scope of future US10/Euro6 regulation levels. The fully variable valve actuation is also required to develop new engine braking strategies, which is one of the key features for heavy duty engines. The ability to pilot each valve individually provides many combustion feature possibilities like: • Use of Miller effect playing on intake valve opening duration • Use of variable air motion by modifying intake valve lift separately from one port to another one • Manage exhaust temperature by cylinder shut off and isolate the non-fired ones • Injection at breathing top dead centre to perform partially or full homogeneous combustion. This presentation highlights the potential benefits of Miller cycle on different engine speeds and loads. It can be stated that both early and late Miller bring benefits on NOx/ Soot trade off on low load points, whatever the engine speed.