An internal combustion engine includes an electro-hydraulic system for variable actuation of intake valves where each cylinder has two intake valves, associated with two intake conduits. A first conduit is generates within the cylinder a tumble motion of airflow introduced therein, when the intake valve associated thereto is at least partially opened. The second intake conduit generates within the cylinder a swirl motion of airflow introduced therein when the second intake valve is at least partially opened. A controller of controls one or more control valves to open only one of the intake valves of each cylinder in a condition of reduced engine operation, below a predetermined load and/or a predetermined speed of the engine, and to always open both intake valves in the remaining conditions of engine operation. The first intake valve is the only valve to be opened in the reduced engine operation 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.

A combustion engine is provided having combustion chambers with reciprocating pistons, intake ports and exhaust ports. Transfer ports may be provided between adjacent combustion chambers to provide a transfer channel that closes during a high load mode of operation of the engine and opens during a partial load mode of operation. Also provided are embodiments in which exhaust ports of adjacent combustion chambers are joined into a common exhaust channel that communicates with an exhaust header of the engine through valve means that open during the high load mode of operation of said engine and close during a partial load mode of operation.

Methods and systems are provided for reducing hydrocarbon emissions from an engine. In one example, a method may include adjusting timing profiles of a first and a second exhaust valve to selectively allow pneumatic communication between a cylinder and exhaust ports of an exhaust manifold during an engine cold start.

Methods and systems are provided for reducing hydrocarbon emissions from an engine. In one example, a method may include adjusting timing profiles of a first and a second exhaust valve to selectively allow pneumatic communication between a cylinder and exhaust ports of an exhaust manifold during an engine cold start.

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.

A valvetrain for a type II engine comprises a valve bridge, a switching rocker arm, a center capsule, a first auxiliary rocker arm, and a first auxiliary capsule. The selectively switching rocker arm is configured to switch configurations to transfer a first valve actuation profile from a first overhead cam lobe to the valve bridge center point and to transfer a second valve actuation profile from a second overhead cam lobe to the center point. The center capsule is configured to switch between an active state and a lost motion state. The first auxiliary rocker arm is configured to transfer a first auxiliary valve actuation profile from a third overhead cam lobe to the valve bridge first valve mounting area. The valvetrain can further comprise a second auxiliary rocker arm and a second auxiliary capsule.

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, a method may include supplying air to an exhaust system at a location downstream of an emissions control device via the first exhaust manifold, the air not having participated in combustion in the engine, the first exhaust manifold in fluidic communication with a first exhaust valve of a cylinder and an intake manifold, the cylinder including a second exhaust valve in fluidic communication with the second exhaust manifold. The method may further include adjusting an amount of fuel injected to the engine in response to output of a first oxygen sensor, the first oxygen sensor positioned in the exhaust system upstream of the emissions control device.

A valvetrain for a type II engine comprises a valve bridge, a switching rocker arm, a center capsule, a first auxiliary rocker arm, and a first auxiliary capsule. The selectively switching rocker arm is configured to switch configurations to transfer a first valve actuation profile from a first overhead cam lobe to the valve bridge center point and to transfer a second valve actuation profile from a second overhead cam lobe to the center point. The center capsule is configured to switch between an active state and a lost motion state. The first auxiliary rocker arm is configured to transfer a first auxiliary valve actuation profile from a third overhead cam lobe to the valve bridge first valve mounting area. The valvetrain can further comprise a second auxiliary rocker arm and a second auxiliary capsule.

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, an air-fuel control method for the engine system may include flowing air from the intake manifold through a plurality of engine cylinders to a junction of the exhaust passage and a bypass passage in response to a condition, the junction positioned along the exhaust passage between first and second emission control devices. The method may further include flowing exhaust gas to the first emission control device while flowing the air to the junction.