An engine system includes main exhaust ports fluidly communicating with each combustion chamber. An exhaust variable valve lift apparatus controls an operation of a main exhaust valve which closes or opens each main exhaust port. A main exhaust manifold is connected with the main exhaust ports. Scavenge exhaust ports fluidly communicate with each combustion chamber. A variable scavenge apparatus controls an operation of a scavenge valve which closes and opens each scavenge exhaust port. A scavenge manifold is connected with the scavenge exhaust ports. A controller is configured to control operations of the exhaust variable valve lift apparatus and the variable scavenge apparatus according to a vehicle operation state.

A method for cold start pre-warming of a pressure-charged internal combustion engine and/or of an exhaust gas aftertreatment device of a internal combustion engine, includes arranging a cold-starting aid in the intake duct for warming the charge air while the engine is stationary. The internal combustion engine has at least one working cylinder with at least one inlet valve and at least one outlet valve and further includes a device for setting a valve position. The internal combustion engine can be pressure-charged by a pressure-charging device operable by an electric motor. In the method, after detection of a cold start of the internal combustion engine: the cold-starting aid is activated while the engine is stationary; electric-motor operation of the pressure-charging device is activated; and a valve overlap between at least one inlet valve and at least one outlet valve is set.

A fuel removal method is for an internal combustion engine that has a closed- and open-loop control system and a lubricant circuit containing a lubricant. The closed- and open-loop control system has characteristic values for operation of the internal combustion engine. The method includes carrying out a load point shift starting from a first operating point of the internal combustion engine to a second operating point of the internal combustion engine with the aid of the closed- and open-loop control system. The load point shift is carried out when a fuel characteristic value, which characterizes a fuel quantity formed in the lubricant, is greater than or equal to a fuel threshold value. The second operating point having a second scavenging gradient which is greater than a first scavenging gradient of the first operating point.

An engine system may include main exhaust ports fluidly communicated with each combustion chamber, main exhaust valves opening and closing each main exhaust port, a main exhaust manifold connected with the main exhaust ports, scavenge exhaust ports fluidly communicated with the each combustion chamber, scavenge valves opening and closing the each scavenge exhaust port, a scavenge manifold connected with the scavenge exhaust ports, in which at least a part of an exhaust gas passing through the scavenge manifold is re-circulated to the combustion chamber to be burned.

A controller for an internal combustion engine is provided. The engine includes a compressor, a three way catalyst, a canister, an evaporated fuel passage, an ejector, and a purge control valve. The controller includes an ECU. The ECU is configured to decrease an opening degree of the purge control valve in response to an increase in pressure on the downstream side of the compressor in a lean supercharging range. The is a range in which an operation air-fuel ratio of the internal combustion engine is leaner than a theoretical air-fuel ratio of the internal combustion engine, and in which the pressure on the downstream side of the compressor is higher than pressure on the upstream side of the compressor.

A system and methods are described for a turbocharged engine, comprising powering the engine using a first operating cylinder, supplementing the power using a second switchable cylinder, deactivating the second switchable cylinder responsive to a load below a first threshold, and closing a first shut-off valve downstream of a compressor during the partial deactivation to prevent a first turbocharger from imparting a delivery action into a second compressor during the partial deactivation. Embodiments are further described wherein a bypass line in a second exhaust line further serves as a short-circuit line to prevent the second compressor from imparting a delivery action against the closed first shut-off valve. A variable valve timing is then included to further optimize the combustion process during the partial deactivation.

A method and system for perform a charge exchange in internal combustion engine comprising an additional intake and exhaust valve lifts performed during positive pressure gradients between the intake and exhaust systems to reducing scavenging losses and increase torque during low engine speeds.

Systems, apparatus, and methods are disclosed that include an internal combustion engine having a plurality of cylinders and at least one camshaft for opening at least one valve associated with the at least one cylinder. The camshaft includes a cam with a cam lobe defining a cam lobe profile having a base circle portion on a base circle of the cam lobe, a main cam lobe portion, and a low lift dwell portion that extends a constant height from the base circle along a substantial portion of the base circle to increase valve opening overlap and cylinder scavenging.

A two-stroke internal combustion engine includes a diversion fin and an allowance slot. The diversion fin is a structure that has flanges at two ends and a rectangular longitudinal cross section profile. The diversion fin is clamped by a cylinder head and a cylinder block. The diversion fin extends along the diameter direction of the cylinder head and is positioned between an air inlet channel and an air exhaust channel. The diversion fin separates the air inlet channel from the air exhaust channel. The upper end of the diversion fin is provided with a transverse through groove at a position corresponding to an oil nozzle of an oil injector. The allowance slot is disposed on a piston and is positioned in the center of a combustor. The position of the allowance slot corresponds to the position of the diversion fin.

A method and device for operating an internal combustion engine having a supercharging system that has an exhaust turbocharger and an electrically driven compressor. An output of the exhaust turbocharger is adjustable by a control element. A boost pressure setpoint is determined for achieving an increased engine torque setpoint. The supercharging system is adjusted to build up the actual boost pressure in accordance with the boost pressure setpoint and a positive scavenging gradient in a cylinder of the internal combustion engine is adjusted as the overriding command variable for driving the supercharging system.