An engine EGR system is provided, which includes an engine body, an intake passage, an exhaust passage and an EGR passage configured to recirculate exhaust gas as EGR gas to the intake passage. The EGR passage includes an EGR cooler and an EGR internal passage constituting the EGR passage upstream of the EGR cooler, and including a passage passing through a cylinder head. The EGR internal passage has a bent pipe part including a first bent portion at which an upstream portion of the EGR internal passage is bent away from a gas inflow port of the EGR cooler, a second bent portion located downstream of the first bent portion and bending the EGR internal passage toward the gas inflow port, and an intermediate portion connecting the first and the second bent portions by being disposed therebetween. The water-cooling passage is disposed around the bent pipe part.

An EGR gas distributor includes an inflow portion into which EGR gas that has passed through an EGR valve flows, a first EGR port connected to a section of the intake manifold in which intake air introduced into the first cylinder flows, a second EGR port connected to a section of the intake manifold in which intake air introduced into the second cylinder flows, a first gas passage that connects the inflow portion and the first EGR port to each other, and a second gas passage that connects the first gas passage and the second EGR port to each other. A shortest path between the first EGR port and the second EGR port is longer than both of a shortest path between the inflow portion and the first EGR port and a shortest path between the inflow portion and the second EGR port.

An EGR gas distributor includes an inflow portion into which EGR gas that has passed through an EGR valve flows, a first EGR port connected to a section of the intake manifold in which intake air introduced into the first cylinder flows, a second EGR port connected to a section of the intake manifold in which intake air introduced into the second cylinder flows, a first gas passage that connects the inflow portion and the first EGR port to each other, and a second gas passage that connects the first gas passage and the second EGR port to each other. A shortest path between the first EGR port and the second EGR port is longer than both of a shortest path between the inflow portion and the first EGR port and a shortest path between the inflow portion and the second EGR port.

An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

An intake passage includes: a main intake passage provided with a throttle valve and extending from one side toward the other side along a cylinder bank; and a bypass passage provided with an EGR valve and connected to a part of the main intake passage located toward the other side with respect to the throttle valve. The bypass passage extends from a branch of the main intake passage toward the one side and then turns back and extends toward the other side. The EGR valve is located in a part of the bypass passage extending toward the other side and overlapping with a part extending from the branch to the one side.

An internal combustion engine having a turbocharger with variability at the compressor inlet, and a turbocharger. An internal combustion engine having a turbocharger, and a turbocharger, are described. A device which both performs a change in the cross section of the compressor inlet and brings about an adjustment of the exhaust gas recirculation rate is arranged in the region of the compressor inlet. As a result, the turbocharger is of space-saving and low-cost construction in the compressor inlet region.

A cylinder head includes: a plurality of exhaust ports configured to lead out exhaust gas from combustion chambers; a plurality of intake ports configured to introduce fresh air into the combustion chambers; an intake air aggregate part configured to aggregate the plurality of intake ports; and a second EGR pipe in which EGR gas flows, wherein exhaust outlets of the plurality of exhaust ports and an EGR gas inlet of the second EGR pipe are arranged side-by-side on a flat left side surface, and a fresh air inlet of the intake air aggregate part and an EGR gas outlet of the second EGR pipe are arranged side-by-side on a flat right side surface.

A system for deactivating at least one predetermined cylinder of an operational multicylinder engine, with each cylinder including an intake duct with an inlet connected to the intake manifold and an outlet connected to the cylinder in order to allow the intake of combustion gases from the intake manifold to the cylinder, may include a first movable sealing means suitable for sealing the inlet of said intake duct of the predetermined cylinder, a recirculation duct suitable for connecting said intake duct of said predetermined cylinder to an exhaust gas supply, and a second movable sealing means suitable for sealing said recirculation duct.

A system for deactivating at least one predetermined cylinder of an operational multicylinder engine, with each cylinder including an intake duct with an inlet connected to the intake manifold and an outlet connected to the cylinder in order to allow the intake of combustion gases from the intake manifold to the cylinder, may include a first movable sealing means suitable for sealing the inlet of said intake duct of the predetermined cylinder, a recirculation duct suitable for connecting said intake duct of said predetermined cylinder to an exhaust gas supply, and a second movable sealing means suitable for sealing said recirculation duct.