An internal combustion engine for a vehicle is provided, having at least one cylinder with a first gas exchange inlet valve, a second gas exchange inlet valve, a first gas exchange outlet valve, a second gas exchange outlet valve, and a piston with a piston crown which has a plurality of valve seat pockets. In each case one valve seat pocket is provided for the first gas exchange inlet valve, the second gas exchange inlet valve, the first gas exchange outlet valve and the second gas exchange outlet valve, and the plurality of valve seat pockets have at least partially different depths. Alternatively, one valve seat pocket is provided for the first gas exchange inlet valve and the first gas exchange outlet valve, and no valve seat pocket is provided for the second gas exchange inlet valve and/or for the second gas exchange outlet valve.

Disclosed is a control device for an engine provided with a first intake valve and a second intake valve in an intake port. The control device comprises: a variable valve operating mechanism (72) configured to control a valve opening timing and a valve closing timing of an intake valve (21a); and a variable valve operating mechanism (72) configured to control a valve opening timing and a valve closing timing of an intake valve (21b), independently of the intake valve (21a). The latter variable valve mechanisms (72) is operable, in an intake stroke of the engine, to close the intake valve (21b) after the elapse of a delay time rt since the intake valve (21a) is closed. The delay time rt is a time period during which a pressure wave generated upon closing of the intake valve (21a) reaches the intake valve (21b) through the intake port (16).

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.

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.

An internal combustion engine is described, and includes a method for operating that includes determining an observed carbon monoxide (CO) ratio in an exhaust gas feedstream, determining an observed in-cylinder scavenging based upon the observed CO ratio in the exhaust gas feedstream, and controlling, by a controller, control states for the variable cam phasing system to control opening times of engine intake valves in relation to closing times of engine exhaust valves based upon the observed in-cylinder scavenging.

An internal combustion engine is described, and includes a method for operating that includes determining an observed carbon monoxide (CO) ratio in an exhaust gas feedstream, determining an observed in-cylinder scavenging based upon the observed CO ratio in the exhaust gas feedstream, and controlling, by a controller, control states for the variable cam phasing system to control opening times of engine intake valves in relation to closing times of engine exhaust valves based upon the observed in-cylinder scavenging.

Turbo or super charged intake tract diverter valve system, upstream of a throttle valve, includes a closure means (10) for a diversion aperture (4.1) in the intake tract (3) to vent pressurised gases within to a bypass path or atmosphere; the closure means having a transfer aperture (12) facilitating a net three due to a pressure differential on its opposite sides of the closure means (10) so as to close or keep closed the diversion aperture (4.1). When gas pressure on opposite sides of the closure means is equal, and when an upstream side (10.1) of the closure means (10) has a pressure greater than a downstream side (5.1), then it will open the diversion aperture (4.1). An actuation means opens a control aperture (6) to create the necessary pressure differential on the closure means (10) to thereby cause same to open the diversion aperture (4.1).

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.

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.

Turbo or super charged intake tract diverter valve system, upstream of a throttle valve, includes a closure means (10) for a diversion aperture (4.1) in the intake tract (3) to vent pressurized gases within to a bypass path or atmosphere; the closure means having a transfer aperture (12) facilitating a net force due to a pressure differential on its opposite sides of the closure means (10) so as to close or keep closed the diversion aperture (4.1). When gas pressure on opposite sides of the closure means is equal, and when an upstream side (10.1) of the closure means (10) has a pressure greater than a downstream side (5.1), then it will open the diversion aperture (4.1). An actuation means opens a control aperture (6) to create the necessary pressure differential on the closure means (10) to thereby cause same to open the diversion aperture (4.1).