Abstract: Methods and systems are provided for exhaust flow in an engine system including a split-exhaust manifold for expediting exhaust catalyst light-off and engine warm-up while reducing condensation in the engine system. In one example, a method may include, before exhaust catalyst light-off, flowing all or more exhaust gases, via a first exhaust valve and a first exhaust manifold, to an exhaust catalyst by passing a heat exchanger. Further, after light-off but before engine coolant warms up to a threshold temperature, all or more exhaust may be delivered to the heat exchanger, via a second exhaust valve and a second different manifold, prior to flowing to the exhaust catalyst; and exhaust gas recirculation may not be provided until the coolant reaches the threshold temperature to reduce condensation.

Abstract: Embodiments for a charge air cooler are provided. In one example, an engine method comprises during a first mode, decreasing a volume of a charge air cooler in response to a compressor operation upstream of the charge air cooler. In this way, compressor surge may be prevented.

Abstract: Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, one or more valves of a set of first exhaust valves coupled to the second exhaust manifold may be deactivated in response to select engine operating conditions, while maintaining active all valves of a set of second exhaust valves coupled to the first exhaust manifold. The select engine operating conditions may include one or more of a deceleration fuel shut-off condition, a part throttle condition, and a cold start condition.

Abstract: Systems and methods for operating a driveline of a hybrid vehicle are disclosed. In one example, an engine may enter or stay in one of two cylinder modes in response to a request to a negative torque capacity of an electric machine being insufficient to provide a desired driveline braking torque. One cylinder mode operates cylinders with cylinder valves held closed and without fuel being injected to the cylinders while the other cylinder mode operates cylinders with valves that open and close without fuel being injected to the cylinders.

Abstract: Methods and systems are provided for adjusting a cylinder deactivation pattern to improve camshaft phasing. In response to a request for actuating a camshaft phaser of a variable cam timing device, a cylinder deactivation pattern is adjusted by reactivating cylinders that were deactivated while deactivating other cylinders that were active, while maintaining a total number of deactivated/active cylinders. Cylinders are selected for reactivation or deactivation based on their individual camshaft torsion signatures so that sufficient cam torque is generated to actuate the phaser and provide the requested phasing.

Abstract: Methods and systems are provided for a wastegate of a turbocharger including a valve plate, valve actuation mechanism, and a bifurcated wastegate passage. In one example design, the wastegate may include a valve plate having an interior with a multiplane curved surface and a first mating feature centered along the curved surface, the curved surface forming a raised edge and a side opening on opposite sides of the valve plate; and a passage bifurcated by a central wall, an end of the central wall including a second mating feature adapted to have face-sharing contact with the first mating feature. The first mating feature may be either a rib or recessed slot formed on the valve plate, and the second mating feature may be one end of the central wall.

Abstract: Methods and systems are provided for exhaust heat recovery and EGR cooling via a single heat exchanger. In one example, a method may include selecting a specific mode of operation of an engine exhaust system with the heat exchanger based on engine operating conditions and an estimated fuel efficacy factor. The fuel efficiency factor may take into account fuel efficacy benefits from EGR and exhaust heat recovery.

Abstract: Methods and systems are provided for operating an engine with variable displacement engine (VDE) operation coupled to a twin scroll turbocharger. One method comprises directing exhaust from a first outer cylinder and a first inner cylinder of four cylinders to a first scroll of the twin scroll turbocharger, directing exhaust from a second outer cylinder and a second inner cylinder of the four cylinders to a second scroll of the twin scroll turbocharger, and during a first condition, firing all four cylinders with uneven firing.

Abstract: Methods and systems are provided for controlling vibrations during transitions between engine operating modes in a four-cylinder engine. One method includes timing a transition in engine operation between two-cylinder, three-cylinder, and four-cylinder modes with a sequence of firing events such that successive firing events are separated by at least 120 crank angle degree intervals. Vibrations resulting from transitions may be countered by adjusting active mounts, the active mounts being adjusted in synchronization with a valvetrain switching solenoid.

Abstract: Systems and methods for operating an engine with deactivating valves are presented. In one example, a groove in a camshaft controls oil flow to a valve operator that selectively activates and deactivates a poppet valve of a cylinder. The groove moves with the camshaft so that oil delivery to the valve operator is timed properly to deactivate and reactivate the cylinder.

Abstract: Systems and methods for increasing EGR gas temperature for an engine that includes at least one dedicated EGR cylinder. The dedicated EGR cylinder may provide exhaust gas to engine cylinders and the exhaust gas does not include exhaust gases from cylinders other than the dedicated EGR cylinder. The dedicated EGR cylinder may allow the engine to operate at higher EGR dilution levels.

Abstract: Methods and systems for adjusting a branch communication and wastegate valve in a dual scroll turbocharger system are provided. In one example, a method may include adjusting the branch communication and wastegate valve in a passage connecting a first scroll, a second scroll, and a wastegate passage may control an amount of exhaust flow to a turbine during certain engine operating conditions.

Abstract: Methods and systems are provided for operating an engine with variable displacement engine (VDE) operation coupled to a twin scroll turbocharger. One method comprises directing exhaust from a first outer cylinder and a first inner cylinder of four cylinders to a first scroll of the twin scroll turbocharger, directing exhaust from a second outer cylinder and a second inner cylinder of the four cylinders to a second scroll of the twin scroll turbocharger, and during a first condition, firing all four cylinders with uneven firing.

Abstract: Systems and methods for operating a compressor and a compressor recirculation valve of a turbocharged engine to avoid the possibility of compressor surge are presented. The systems and methods position the compressor recirculation valve responsive to a compressor surge line that is based on two other compressor surge lines that may be a function of compressor pressure ratio and compressor flow.

Abstract: Methods and systems are provided for controlling transitions between engine operating modes in a four-cylinder engine. One method includes transitioning engine operation between two-cylinder, three-cylinder, and four-cylinder modes wherein the transitioning includes a sequence of firing events such that successive firing events are separated by at least 120 crank angle degree intervals.

Abstract: Methods and systems are provided for exhaust flow in an engine system including a split-exhaust manifold for expediting exhaust catalyst light-off and engine warm-up while reducing condensation in the engine system. In one example, a method may include, before exhaust catalyst light-off, flowing all or more exhaust gases, via a first exhaust valve and a first exhaust manifold, to an exhaust catalyst by passing a heat exchanger. Further, after light-off but before engine coolant warms up to a threshold temperature, all or more exhaust may be delivered to the heat exchanger, via a second exhaust valve and a second different manifold, prior to flowing to the exhaust catalyst; and exhaust gas recirculation may not be provided until the coolant reaches the threshold temperature to reduce condensation.

Abstract: Various methods for compensating variation in the geometry and position of linkages and valve seats in wastegate assemblies are provided. In one example, a method of operating a wastegate in an internal combustion engine comprises, at engine startup, placing a wastegate valve at a seat, recording a position of the seat and associating the seat position with one or more operating parameters, and modifying a position of a wastegate actuator based on the seat position throughout engine operation.

Abstract: Methods and systems are provided for operating an engine with variable displacement engine (VDE) operation coupled to a twin scroll turbocharger. One method comprises directing exhaust from a first outer cylinder and a first inner cylinder of four cylinders to a first scroll of the twin scroll turbocharger, directing exhaust from a second outer cylinder and a second inner cylinder of the four cylinders to a second scroll of the twin scroll turbocharger, and during a first condition, firing all four cylinders with uneven firing.

Abstract: Methods and systems are provided for controlling engine operation. One method comprises during a first condition, operating the engine with a single cylinder deactivated and remaining cylinders activated with a first intake duration, and during a second condition, operating the engine with the single cylinder deactivated and the remaining cylinders activated with a second intake duration. The method further comprises during a third condition, operating the engine with all cylinders activated.

Abstract: Methods and systems are provided for reducing torque transients experienced when a dedicated EGR cylinder is transitioned in to or out of dedicated EGR mode. During a transition, each of an intake throttle and a wastegate is adjusted in opposing directions. Throttle and wastegate adjustments are coordinated with adjustments to spark timing and intake cam timing to provide sufficient torque reserve for the transition.