Systems and methods are provided for operating an internal combustion engine in a two-stroke mode or a four-stroke mode to achieve greater fuel efficiency and minimize emissions. The system comprises a mode-adaptable valve; a valve rocker arm to actuate opening and closing of the mode adaptable valve; a cam follower of a first cam for carrying out a two-stroke mode; a cam follower of a second cam for carrying out a four-stroke mode; and a pin to mechanically couple the valve rocker arm to the cam follower of the first cam or the cam follower of the second cam. Coupling the valve rocker arm to the cam follower of the first cam enables a two-stroke mode and coupling the valve rocker arm to the cam follower of the second cam enables a four-stroke mode.

The invention relates to a method (100) for controlling a powertrain system (10) of a vehicle (1) during gear upshifting, said powertrain system comprising: an internal combustion engine system (11) comprising an internal combustion engine (12) configured to output a rotational speed (W1) via an engine output shaft (8); a transmission arrangement (14) having a number of gear stages to obtain a set of gears, the transmission arrangement being operatively connected to the internal combustion engine via a transmission input shaft (64) and further having a transmission output shaft (24) for providing a rotational speed to one or more drive wheels (26) of the vehicle; the method comprising the steps of: operating (110) the engine in a four-stroke operation to provide engine rotational speed output via the engine output shaft; receiving (120) an indication of an intended upshifting from a gear of the set of gears to a higher gear of the sets of gears; reducing (130) the rotational speed of the engine output shaft by adjusting the operation of the engine from the four-stroke operation to a two-stroke braking operation; and, when said engine is in the two-stroke braking operation, performing (140) the intended upshifting from said gear of the set of gears to said higher gear of the sets of gears.

The invention relates to a method (100) for controlling a powertrain system (10) of a vehicle (1) during gear upshifting, said powertrain system comprising: an internal combustion engine system (11) comprising an internal combustion engine (12) configured to output a rotational speed (W1) via an engine output shaft (8); a transmission arrangement (14) having a number of gear stages to obtain a set of gears, the transmission arrangement being operatively connected to the internal combustion engine via a transmission input shaft (64) and further having a transmission output shaft (24) for providing a rotational speed to one or more drive wheels (26) of the vehicle; the method comprising the steps of: operating (110) the engine in a four-stroke operation to provide engine rotational speed output via the engine output shaft; receiving (120) an indication of an intended upshifting from a gear of the set of gears to a higher gear of the sets of gears; reducing (130) the rotational speed of the engine output shaft by adjusting the operation of the engine from the four-stroke operation to a two-stroke braking operation; and, when said engine is in the two-stroke braking operation, performing (140) the intended upshifting from said gear of the set of gears to said higher gear of the sets of gears.

The invention relates to a method (100) for controlling a powertrain system (10) of a vehicle (1) during gear upshifting, said powertrain system comprising: an internal combustion engine system (11) comprising an internal combustion engine (12) configured to output a rotational speed (W1) via an engine output shaft (8); a transmission arrangement (14) having a number of gear stages to obtain a set of gears, the transmission arrangement being operatively connected to the internal combustion engine via a transmission input shaft (64) and further having a transmission output shaft (24) for providing a rotational speed to one or more drive wheels (26) of the vehicle; the method comprising the steps of: operating (110) the engine in a four-stroke operation to provide engine rotational speed output via the engine output shaft; receiving (120) an indication of an intended upshifting from a gear of the set of gears to a higher gear of the sets of gears; reducing (130) the rotational speed of the engine output shaft by adjusting the operation of the engine from the four-stroke operation to a two-stroke braking operation; and, when said engine is in the two-stroke braking operation, performing (140) the intended upshifting from said gear of the set of gears to said higher gear of the sets of gears.

The invention relates to a method (100) for controlling a powertrain system (10) of a vehicle (1) during gear upshifting, said powertrain system comprising: an internal combustion engine system (11) comprising an internal combustion engine (12) configured to output a rotational speed (W1) via an engine output shaft (8); a transmission arrangement (14) having a number of gear stages to obtain a set of gears, the transmission arrangement being operatively connected to the internal combustion engine via a transmission input shaft (64) and further having a transmission output shaft (24) for providing a rotational speed to one or more drive wheels (26) of the vehicle; the method comprising the steps of: operating (110) the engine in a four-stroke operation to provide engine rotational speed output via the engine output shaft; receiving (120) an indication of an intended upshifting from a gear of the set of gears to a higher gear of the sets of gears; reducing (130) the rotational speed of the engine output shaft by adjusting the operation of the engine from the four-stroke operation to a two-stroke braking operation; and, when said engine is in the two-stroke braking operation, performing (140) the intended upshifting from said gear of the set of gears to said higher gear of the sets of gears.

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.

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.

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.

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.

A method for operating an internal combustion engine having an engine with a first number of cylinders and a second number of cylinders and a supercharger arrangement, wherein a charge air flow supplied to the engine is compressed by means of at least one compressor and at least one turbine is acted on by an exhaust gas flow discharged from the engine. In a main operating mode, the engine operates the first number of cylinders in two-stroke operation and the second number of cylinders in four-stroke operation. A scavenging gradient of the engine is greater for the cylinders operated in the two-stroke operation than for the cylinders operated in the four-stroke operation.