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 setting a cam timing correction based on a difference between a first value and a second value of a flow through an exhaust gas recirculation (EGR) passage, the first value determined based on a first parameter set including a cylinder valve overlap area and the second value determined based on a second parameter set not including the cylinder valve overlap area, and operating at least one of an intake cam and an exhaust cam at a corrected timing using the cam timing correction. In this way, the flow through the EGR passage may be adjusted even without active control of a valve coupled in the EGR passage.

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.

An internal combustion engine for a motor vehicle includes a combustion chamber with a gas exchange valve which is movable between an open position and a first closed position. The gas exchange valve is movable on its path from the open position in a direction of the first closed position into an intermediate position located between the open position and the first closed position and is holdable in the intermediate position at least during a part of a compression cycle of the combustion chamber following the open position of the gas exchange valve and is movable into a second closed position following the intermediate position. The part comprises more than a half of the compression cycle and less than a whole of the compression cycle. The gas exchange valve is an inlet valve via which the combustion chamber is supplyable at least with air.

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.

Methods and systems are provided for adjusting amount of directly injected fuel scavenged via a second exhaust manifold of a split exhaust engine system. In one example, a method may include adjusting a start of injection of a fuel direct injection into an engine cylinder, the cylinder including a first exhaust valve coupled to a first exhaust manifold and a second exhaust valve coupled to a second exhaust manifold, the second exhaust manifold coupled to an intake of the engine, based on a closing timing of the second exhaust valve and dependent on an operating condition, and adjusting a position of a bypass valve of the second exhaust manifold based on the adjusted start of injection. In this way, the amount of scavenged fuel may be increased or decreased based on the operating condition.

Systems and methods for determining which of an intake valve and an exhaust valve is to be deactivated first when an engine is operated in a variable displacement mode. In one example, an exhaust valve of the cylinder is deactivated before an intake valve of the cylinder when the engine is operated in a static variable displacement operating mode.

Methods, devices, controllers, and algorithms are described for operating an internal combustion engine wherein at least some firing opportunities utilize low temperature gasoline combustion (LTGC). Other firing opportunities may be skipped or utilize some other type of combustion, such as spark ignition. The nature of any particular firing opportunity is dynamically determined during engine operation, often on a firing opportunity by firing opportunity basis. Firings that utilize LTGC produce little, if any, nitrous oxides in the exhaust stream and thus, in some implementations, may require no aftertreatment system to remove them from the exhaust stream.

An internal combustion engine system includes an engine with a plurality of pistons housed in respective ones of a plurality of cylinders, an air intake system to provide air to the plurality of cylinders through respective ones of a plurality of intake valves, an exhaust system to release exhaust gas from the plurality of cylinders through respective one of a plurality of exhaust valves. A valve train is provided for cylinder deactivation of a first part of the plurality of cylinders and compression release braking on a second part of the plurality of cylinders.

Methods and systems are provided for extending a duration of engine idle-stop while reducing a frequency of engine restart from idle-stop. In one example, in response to engine restart conditions where combustion torque is not necessary, an engine can be rotated electrically, without fuel delivery, via an electric motor. The unfueled engine spinning via the motor drives an FEAD which in turns drives an actuator coupled to the FEAD, such as an AC compressor or an automatic transmission oil pump.