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.

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.

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.

Systems and methods are provided for controlling exhaust gas recirculation (EGR). In one example, an engine system includes a first EGR valve coupling an exhaust manifold to an engine exhaust system, a second EGR valve coupling the exhaust manifold to an engine intake system, and a control unit. The control unit selectively adjusts a position of the first EGR valve based on a target amount, and adjusts a position of the second EGR valve based on the target amount and a position of the first EGR valve. Responsive to a first degradation condition of the first EGR valve, the control unit adjusts the position of the second EGR valve based on the target amount and based on a pressure of the first exhaust manifold, and responsive to a second degradation condition of the first EGR valve, adjusts the position of the second EGR valve based on the target amount.

An engine system may include an engine including a plurality of combustion chambers for generating a driving force by combustion of fuel, an exhaust gas purification device mounted in an exhaust line through which exhaust gas discharged from the combustion chamber flows, an EGR gas collecting device configured for collecting a part of the exhaust gas from an exhaust manifold of the engine and supplying the exhaust gas to an intake manifold of the engine, and an EGR gas supply control valve provided between the EGR gas collecting device and the intake manifold and adapted to regulate a flow rate of EGR gas supplied to the intake manifold.

An engine system may include an engine including a plurality of combustion chambers for generating a driving force by combustion of fuel, an exhaust gas purification device mounted in an exhaust line through which exhaust gas discharged from the combustion chamber flows, an EGR gas collecting device configured for collecting a part of the exhaust gas from an exhaust manifold of the engine and supplying the exhaust gas to an intake manifold of the engine, and an EGR gas supply control valve provided between the EGR gas collecting device and the intake manifold and adapted to regulate a flow rate of EGR gas supplied to the intake manifold.

Methods and systems are provided for controlling and coordinating control of a post-catalyst exhaust throttle and an EGR valve to expedite catalyst heating. By closing both valves during an engine cold start, an elevated exhaust backpressure and increased heat rejection at an EGR cooler can be synergistically used to warm each of an engine and an exhaust catalyst. The valves may also be controlled to vary an amount of exhaust flowing through an exhaust venturi so as to meet engine vacuum needs while providing a desired amount of engine EGR.

Methods and systems are provided for controlling and coordinating control of a post-catalyst exhaust throttle and an EGR valve to expedite catalyst heating. By closing both valves during an engine cold start, an elevated exhaust backpressure and increased heat rejection at an EGR cooler can be synergistically used to warm each of an engine and an exhaust catalyst. The valves may also be controlled to vary an amount of exhaust flowing through an exhaust venturi so as to meet engine vacuum needs while providing a desired amount of engine EGR.

This intake apparatus for an internal combustion engine having a first bank and a second bank includes: an intake pipe including one new-air intake pipe, two branched pipes, and a junction connecting the new-air intake pipe to the two branched pipes; an EGR gas pipe connected to the junction; and a partitioning member placed around an opening in the EGR gas pipe that opens toward the intake pipe. The partitioning member defines an EGR gas storage chamber. The EGR gas storage chamber has first-bank and second-bank flow passages in which the EGR gas flows toward the first bank and the second bank. The first and second effective cross-sectional areas in the first-bank flow passage and the second-bank flow passage are smaller than the flow passage cross-sectional area in the opening of the EGR gas pipe.