Methods and systems are provided for a branch communication valve in a twin turbocharger system. A branch communication valve may be positioned adjacent to a dividing wall separating a first scroll and a second scroll of the twin turbocharger. In an open position, the branch communication valve increases fluid communication between the first scroll and the second scroll and in a closed position, the branch communication valve decreases fluid communication between the first scroll and the second scroll.

Methods and systems are provided for a branch communication valve in a twin turbocharger system. A branch communication valve may be positioned adjacent to a dividing wall separating a first scroll and a second scroll of the twin turbocharger. In an open position, the branch communication valve increases fluid communication between the first scroll and the second scroll and in a closed position, the branch communication valve decreases fluid communication between the first scroll and the second scroll.

Provided are methods for operating an internal combustion engine system including: an internal combustion engine provided with a plurality of cylinders, each of which being provided with an air inlet valve and an exhaust gas valve; a fuel supply system configured to supply fuel to the cylinders; an air intake system and an exhaust gas system; a turbocharging arrangement comprising an intake air compressor arranged in the air intake system and an exhaust gas turbine arranged in the exhaust gas system, wherein the intake air compressor is operatively connected to the exhaust gas turbine; a controllable gas feeding device arranged in the air intake system downstream the intake air compressor; an exhaust gas aftertreatment system arranged downstream the exhaust gas turbine; and a wastegate.

Provided are methods for operating an internal combustion engine system including: an internal combustion engine provided with a plurality of cylinders, each of which being provided with an air inlet valve and an exhaust gas valve; a fuel supply system configured to supply fuel to the cylinders; an air intake system and an exhaust gas system; a turbocharging arrangement comprising an intake air compressor arranged in the air intake system and an exhaust gas turbine arranged in the exhaust gas system, wherein the intake air compressor is operatively connected to the exhaust gas turbine; a controllable gas feeding device arranged in the air intake system downstream the intake air compressor; an exhaust gas aftertreatment system arranged downstream the exhaust gas turbine; and a wastegate.

A method of operating exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit linked to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target in step S1 wherein when motor speed=predetermined target then; determining if a motor torque is within a predetermined target in step S2 wherein when motor torque=predetermined target then; determining if a motor temperature is within a predetermined target in step S3 wherein when motor temperature=predetermined target then; and maintaining operation of the exhaust gas recirculation pump.

A method of operating exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit linked to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target in step S1 wherein when motor speed=predetermined target then; determining if a motor torque is within a predetermined target in step S2 wherein when motor torque=predetermined target then; determining if a motor temperature is within a predetermined target in step S3 wherein when motor temperature=predetermined target then; and maintaining operation of the exhaust gas recirculation pump.

An engine system is provided, which includes a supercharger driven by a crankshaft of an engine, an electromagnetic clutch disconnectably connecting the crankshaft to the supercharger, and a controller configured to output a control signal to the electromagnetic clutch. The controller includes a processor configured to execute an uphill-angle detecting module to detect an uphill angle during traveling of a vehicle, an uphill determining module to determine whether the detected uphill angle is above a given first uphill angle, and a boost controlling module to, when the detected uphill angle is above the first uphill angle, control the electromagnetic clutch to connect the crankshaft to the supercharger even when a target torque of the engine is within a not-boosting range.

A marine engine has a powerhead having an cylinder block, a cylinder head, and a crankcase; a supercharger providing charge air for combustion in the powerhead, wherein the supercharger discharges the charge air to an outlet duct; and a charge air cooler cooling the charge air prior to combustion in the powerhead. The charge air cooler has an upstream inlet receiving the charge air from the outlet duct and a downstream outlet discharging the charge air to the cylinder head. The downstream outlet is coupled to the cylinder head by a first one of a rigid seal device and a flexible seal device and the upstream inlet is coupled to the outlet duct by a different, second one of the rigid seal device and flexible joint device.

A marine engine has a powerhead having an cylinder block, a cylinder head, and a crankcase; a supercharger providing charge air for combustion in the powerhead, wherein the supercharger discharges the charge air to an outlet duct; and a charge air cooler cooling the charge air prior to combustion in the powerhead. The charge air cooler has an upstream inlet receiving the charge air from the outlet duct and a downstream outlet discharging the charge air to the cylinder head. The downstream outlet is coupled to the cylinder head by a first one of a rigid seal device and a flexible seal device and the upstream inlet is coupled to the outlet duct by a different, second one of the rigid seal device and flexible joint device.

The invention relates to a method of operating a four stroke internal combustion engine system (1), the engine system (1) comprising:—a four stroke internal combustion engine (2) provided with an intake duct (5),—a turbo compressor (6″) arranged to compress intake flow in the intake duct (5), and—a displacement machine (7) provided in the intake duct (5) downstream the turbo compressor (6″), wherein the displacement machine (7) is arranged to displace intake flow from an inlet to an outlet thereof. The method comprises the step of: operating the displacement machine (7) in a first mode where a pressure ratio (PR) given by a pressure at the outlet of the displacement machine (7) divided by a pressure at the inlet of the displacement machine (7) is substantially equal to 1. The invention also relates to a four stroke internal combustion engine system arranged to be operated by the above method.