A method for heating an exhaust gas aftertreatment component in an exhaust system of an internal combustion engine. At the combustion chamber, a fuel injector for injecting a fuel into the combustion chamber and a spark plug for igniting a flammable fuel-air mixture are arranged. The internal combustion engine has a valve lift curve switching mechanism, which allows for a shift and/or change of the opening times of the exhaust valve. The method includes: intake of fresh air into the combustion chamber, injection of a fuel into the combustion chamber, ignition of an ignitable fuel-air mixture in the combustion chamber when the piston is in a range of 10° KW to 30° KW after the upper ignition dead point, and opening of the exhaust valve when the piston is in a range of 55° KW to 95° KW after the upper ignition dead point.

A method for advancing valve actuation during low load or idle diesel engine conditions to promote aftertreatment heat up comprises switching a cam phaser from a nominal lift position to an advance lift position to open an affiliated valve before nominal. Valve lift is actuated via the cam phaser. The valve is lowered towards nominal closure, and valve closure is interrupted by actuating a latch phaser. Valve closure is extended beyond nominal valve closure.

An exhaust passage structure of an internal combustion includes a first merging passage, a second merging passage, and a third merging passage connecting a third gathering portion in which the exhaust gas flowing through the first merging passage and the exhaust gas flowing through the second merging passage gather and a turbine of a turbocharger. The first merging passage and the second merging passage have respective narrowed portions in which passage cross-sectional areas are minimized. When a total value of passage cross-sectional areas of inlets of exhaust ports in one cylinder is set as a reference passage cross-sectional area A, and the passage cross-sectional areas of the narrowed portions of the first merging passage and the second merging passage are set as narrowed cross-sectional areas B, the exhaust passage structure is configured such that the relationship of 0.5≤(B/A)≤1 is established.

According to one or more embodiments presently described, a method of operating an internal combustion engine that includes injecting fuel into a combustion chamber to form an air-fuel mixture, where the combustion chamber includes a cylinder head, cylinder sidewalls, and a piston that reciprocates within the cylinder sidewalls. The method may also include detecting pre-ignition of the air-fuel mixture during a detected intake or compression stroke of the piston, determining that a super knock condition could occur, and mitigating formation of a super knock condition by deploying a super knock countermeasure within the detected compression stroke.

A control device for an engine is provided, which includes a combustion chamber formed by a cylinder and a piston, an intake air amount adjuster that adjusts an intake air amount supplied to the combustion chamber, a controller switchable of a combustion mode between a fuel-lean first combustion mode and a stoichiometric second combustion mode based on an engine operating state, and an intake air cooler that cools the intake air supplied to the combustion chamber. The controller controls the intake air cooler to start intake air cooling in response to a request for switching the combustion modes, and after the intake air cooling is started, controls the intake air amount adjuster to start the switching of the combustion modes, and then controls the intake air cooler and the intake air amount adjuster so that the switching of the combustion modes ends after the intake air cooling is finished.

A valve actuation system for an internal combustion engine is disclosed. The engine has a first set of cylinders having a first set of exhaust valves and a second set of cylinders having a second set of exhaust valves. The valve actuation system for the exhaust valves includes one or more first cams having a compression-release lobe and a main exhaust lobe adapted to transfer valve actuation motion to the first set of exhaust valves, and one or more second cams having an early exhaust valve opening (EEVO) lobe and a main exhaust lobe adapted to transfer valve actuation motion to the second set of exhaust valves. The valve actuation system may provide any combination of (i) main exhaust valve actuation with or without compression release actuation with (ii) main exhaust valve actuation with or without EEVO for the two sets of cylinders.

A method for operating an engine during a fuel cut-off mode is disclosed. The method may adjust exhaust valve opening timing and exhaust valve lift of one or more cylinders to heat air flowing through the one or more cylinders so that a temperature of an after treatment device may be maintained or increased.

Start-up of an internal combustion engine comprises maintaining one or more engine valves in an engine cylinder in a continuously open state for more than one engine cycle during engine cranking. When it is determined that an engine parameter or transmission oil pressure has reached a predetermined value, maintenance of the one or more engine valves in the continuously open state is discontinued and fuel is subsequently provided to the engine cylinder for engine start-up. In various embodiments, the engine parameter may comprise an engine temperature parameter, an engine pressure parameter or an engine electrical parameter.

A compression-release brake system for operating an exhaust valve of an engine during an engine braking operation. The compression-release brake system comprises a self-contained compression brake control module (CBCM) operatively coupled to the exhaust valve for controlling a lift and a phase angle thereof. The CBCM includes a casing defining an actuator cavity, a actuation piston disposed outside the casing so as to define an actuation piston cavity between the casing and the actuation piston, and a check valve provided between the actuation piston cavity and a compression brake actuator disposed in the actuator cavity. The actuation piston reciprocates relative to the casing. The compression brake actuator includes an actuator element and a biasing spring. The actuator element selectively engages the check valve when deactivated so as to unlock the actuation piston cavity and disengages from the check valve when activated so as to lock the actuation piston cavity.

A method performed by a control unit (11) for controlling exhaust valves (1A-6A, 1B-6B) of cylinders (1-6) in an internal combustion engine (10) is provided. The method comprise controlling (410) a number of first exhaust valves (1A-3A) for a first set of cylinders (1-3) to transfer exhaust gas to a turbine (8)) during part of an exhaust phase (Δt.sub.1) of the first set of cylinders (1-3) via a first exhaust manifold (12). Also, the method comprises controlling (420) a number of second exhaust valves (1B-3B) for the first set of cylinders (1-3) to transfer exhaust gas to an exhaust gas recirculation, EGR, conduit (9)) during part of the exhaust phase (Δt.sub.1) of the first set of cylinders (1-3) via a second exhaust manifold (7). The method further comprises controlling (430) a number of first exhaust valves (4A-6A) for a second set of cylinders (4-6) to transfer exhaust gas to the turbine (8) during part of an exhaust phase (Δt.sub.2) of the second set of cylinders (4-6) via the first exhaust manifold (12). Furthermore, the method comprises controlling (440) a number of second exhaust valves (4B-6B) for the second set of cylinders (4-6) to transfer exhaust gas to the EGR conduit (9) during a part of the exhaust phase (Δt.sub.2) of the second set of cylinders (4-6) via the second exhaust manifold (7). Here, the exhaust phase (Δt.sub.1) of the first set of cylinders (1-3) is separated in time from the exhaust phase (Δt.sub.2) of the second set of cylinders (4-6).

A control unit (11), a computer program, a carrier, an internal combustion engine and a vehicle is also provided.