Abstract: A supercharged diesel engine is equipped with an electronically controlled hydraulic system for variable actuation of the intake valves of the engine. The cam that controls each intake valve has an additional lobe for causing an additional opening of the intake valve, during the exhaust stroke, so as to provide an exhaust-gas recirculation directly inside the engine. Said additional lobe is shaped in such a way as to give rise to a profile of the additional lift of the valve as the crank angle varies with a boot conformation, including an initial stretch with a gentler slope extending from a point of zero lift corresponding to the expansion stroke in the engine cylinder. The engine is moreover equipped with a duct for exhaust-gas recirculation of the long-route type, which picks up the gases from a point of the exhaust duct set downstream of the catalytic converter and of the particulate trap.

Abstract: A supercharged diesel engine is equipped with an electronically controlled hydraulic system for variable actuation of the intake valves of the engine. The cam that controls each intake valve has an additional lobe for causing an additional opening of the intake valve, during the exhaust stroke, so as to provide an exhaust-gas recirculation directly inside the engine. Said additional lobe is shaped in such a way as to give rise to a profile of the additional lift of the valve as the crank angle varies with a boot conformation, including an initial stretch with a gentler slope extending from a point of zero lift corresponding to the expansion stroke in the engine cylinder. The engine is moreover equipped with a duct for exhaust-gas recirculation of the long-route type, which picks up the gases from a point of the exhaust duct set downstream of the catalytic converter and of the particulate trap.