An engine with a boosting system is provided, which includes a turbocharger including a compressor provided in an intake passage of the engine and configured to boost intake air to be supplied to the engine, and a turbine provided in an exhaust passage of the engine. The engine includes an electric supercharger provided in the intake passage downstream of the compressor and configured to operate when the engine operates in a low-speed range, an emission control device provided in the exhaust passage upstream of the turbine and configured to purify exhaust gas discharged from the engine, and an EGR system having a passage connecting a part of the intake passage between the compressor and the electric supercharger to a part of the exhaust passage between the emission control device and the turbine, and configured to recirculate a part of the exhaust gas to the intake passage as EGR gas.

Provided is an intake manifold structure for an internal combustion engine including an intake manifold defining a plurality of branch passages (13) communicating with corresponding intake ports (6) of the internal combustion engine (1) arranged in a cylinder row direction thereof, and provided with additional gas introduction ports (29) communicating with the respective branch passages, and an additional gas introduction passage forming member (16) attached to the intake manifold, and defining an additional gas inlet (35) and additional gas introduction passages (14) communicating the additional gas inlet with the corresponding additional gas introduction ports, wherein the additional gas introduction passage forming member extends across the branch passages, and is provided with a guide wall (33) for defining the additional gas introduction passages in cooperation with an outer surface of the intake manifold and an inner surface of the additional gas introduction passage forming member.

An EGR gas distributor for distributing EGR gas to branch pipes of an intake manifold includes a plurality of gas distribution passages arranged side by side for the branch pipes, a gas inflow passage and a gas chamber to deliver the EGR gas to each of the gas distribution passages. The gas inflow passage includes two, first and second, gas passage parts branched in a single stage. When the EGR gas distributor is mounted on the intake manifold, a passage cross-section of each gas passage part perpendicular to a central axis has an uppermost vertex and a lowermost vertex. The passage cross-sections of the gas passage parts are sized such that their lengths in a vertical direction are gradually longer from an upstream side of the first gas passage part to a downstream side of the second gas passage part.

An EGR gas distributor for distributing EGR gas to branch pipes of an intake manifold includes a plurality of gas distribution passages arranged side by side for the branch pipes, a gas inflow passage and a gas chamber to deliver the EGR gas to each of the gas distribution passages. The gas inflow passage includes two, first and second, gas passage parts branched in a single stage. When the EGR gas distributor is mounted on the intake manifold, a passage cross-section of each gas passage part perpendicular to a central axis has an uppermost vertex and a lowermost vertex. The passage cross-sections of the gas passage parts are sized such that their lengths in a vertical direction are gradually longer from an upstream side of the first gas passage part to a downstream side of the second gas passage part.

Methods and systems are provided for controlling operating of a split exhaust engine system including a scavenge exhaust gas recirculation system based on a composition of constituents within a total flow through the scavenge exhaust gas recirculation system. In one example, a method may include adjusting an engine operating parameter in response to individual flows of each of burnt gases, fresh air, and fuel to an intake passage, upstream of a compressor, from a scavenge manifold coupled to scavenge exhaust valves, the individual flows of each of the burnt gases, fresh air, and fuel determined based on a valve opening overlap between the scavenge exhaust valves and intake valves of the engine.

Methods and systems are provided for adjusting operation of a split exhaust engine system based on a total flow of gases through a scavenge exhaust gas recirculation system of the split exhaust engine system. In one example, a method may include adjusting engine operation in response to a flow of gases to an intake passage, upstream of a compressor, from a scavenge manifold coupled to scavenge exhaust valves, the flow of gases determined based on a valve opening overlap between the scavenge exhaust valves and intake valves of an engine, the scavenge exhaust valves opened at a different time than blowdown exhaust valves coupled to a blowdown manifold coupled to a turbine.

Methods and systems are provided for adjusting operation of a split exhaust engine system based on a total flow of gases through a scavenge exhaust gas recirculation system of the split exhaust engine system. In one example, a method may include adjusting engine operation in response to a flow of gases to an intake passage, upstream of a compressor, from a scavenge manifold coupled to scavenge exhaust valves, the flow of gases determined based on a valve opening overlap between the scavenge exhaust valves and intake valves of an engine, the scavenge exhaust valves opened at a different time than blowdown exhaust valves coupled to a blowdown manifold coupled to a turbine.

An EGR gas distributor includes a gas chamber, a gas inflow passage to introduce EGR gas on its upstream side, gas outflow passages to discharge the EGR gas to branch pipes on their downstream side. An inner wall on a downstream side of the gas chamber is divided into downstream-side divided walls corresponding to the respective gas outflow passages, and the downstream-side divided walls are curved or slanted to be of protrusion-like shape protruding toward the corresponding gas outflow passages. Downstream-side dividing ridges are provided each between the adjacent downstream-side divided walls. An inner wall on the upstream side of the gas chamber is placed to face the downstream-side inner wall and provided with at least one upstream-side ridge protruding toward the downstream-side divided walls in each area corresponding to the downstream-side divided walls.

An EGR gas distributor includes a gas chamber, a gas inflow passage to introduce EGR gas on its upstream side, gas outflow passages to discharge the EGR gas to branch pipes on their downstream side. An inner wall on a downstream side of the gas chamber is divided into downstream-side divided walls corresponding to the respective gas outflow passages, and the downstream-side divided walls are curved or slanted to be of protrusion-like shape protruding toward the corresponding gas outflow passages. Downstream-side dividing ridges are provided each between the adjacent downstream-side divided walls. An inner wall on the upstream side of the gas chamber is placed to face the downstream-side inner wall and provided with at least one upstream-side ridge protruding toward the downstream-side divided walls in each area corresponding to the downstream-side divided walls.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation (EGR) to an intake passage via a ported scavenge manifold. In one example, the ported scavenge manifold includes a first scavenge manifold coupled to a plurality of exhaust runners and a second scavenge manifold coupled to the plurality of exhaust runners via ports. The location of the ports on the exhaust runners combined with adjustments to a bypass valve coupled between the first scavenge manifold and an exhaust passage and an EGR valve coupled between the second scavenge manifold and the intake passage enables exhaust gas to be preferentially flowed to the exhaust passage and blowthrough air to be preferentially flowed to the intake passage under select operating conditions.