Systems and methods for cooling an internal combustion engine via flowing air through the internal combustion engine during select conditions are presented. In one example, lift of intake and/or exhaust poppet valves may be adjusted as a function of engine temperature. In addition, opening and closing timings of intake and exhaust poppet valves may be adjusted as a function of engine temperature.

Systems and methods for cooling an internal combustion engine via flowing air through the internal combustion engine during select conditions are presented. In one example, lift of intake and/or exhaust poppet valves may be adjusted as a function of engine temperature. In addition, opening and closing timings of intake and exhaust poppet valves may be adjusted as a function of engine temperature.

A boosted engine is provided, which includes an engine body formed with a combustion chamber, a spark plug, a fuel injection valve, a booster, a boost controller, and a control unit including an operating range determining module and a compression end temperature estimating module. In a high load range, the fuel injection valve and the spark plug are controlled so that a mixture gas inside the combustion chamber starts combustion through flame propagation by ignition of the spark plug, and unburned mixture gas then combusts by compression ignition, and the boost controller is controlled to bring the booster into a boosting state. When a gas temperature inside the combustion chamber exceeds a given temperature at CTDC, the fuel injection valve is controlled so that a fuel injection end timing occurs on a compression stroke, and the spark plug is controlled so that the mixture gas is ignited after CTDC.

An engine includes: a duration apparatus for adjusting an opening duration of an intake valve, a Cylinder De-Activation (CDA) apparatus for controlling deactivation of an exhaust valve, an igniter, an injector for injecting a fuel, an operation state signal unit for measuring an operation state of a vehicle, and a controller for controlling the operations of the duration apparatus, the CDA apparatus, the igniter, and the injector based on an output signal from the operation state signal unit. A control method for this engine includes: determining, by the controller, whether the operation state of the vehicle corresponds to a CDA operation mode; and when the CDA operation mode is determined, operating the CDA apparatus so as to stop the operations of the igniter and the injector, increase an opening duration of the intake valve, and deactivate the exhaust valve by controlling the CDA apparatus.

A method for determining the mass m of air trapped in each cylinder of an internal combustion engine comprises determining, a value for each quantity of a first group of reference quantities comprising at least intake pressure P measured inside the intake manifold, engine rotation speed n, mass of gases produced by the combustion in the previous operating cycle (OFF) and present in the cylinder, determining, the actual inner volume V of each cylinder as a function of the engine rotation speed n, of the lift H of the intake valve and of the closing delay angle IVC of the intake valve, and determining the mass m of air trapped in each cylinder as a function of the first group of reference quantities and of the actual volume V inside each cylinder, on the basis of the aforesaid quantities P, V, OFF.

A valve rocker arm assembly, a variable air distribution mechanism, and an engine are provided according to the present disclosure. The valve rocker arm assembly includes: an oil inlet hose; a rocker arm shaft, an oil drain channel, an oil return groove, and a first oil path being provided in the rocker arm shaft, the oil drain channel being communicated with the oil return groove by means of the first oil path; a first rocker arm and a second rocker arm rotatably connected onto the rocker arm shaft, a piston cavity, an oil inlet path, an oil drain path and a piston being provided on the second rocker arm; a one-way opening device provided in the oil inlet path and/or the oil inlet hose; and a control valve connected to the oil drain channel

A method for a knock control for an internal combustion engine with at least one cylinder, which is assigned to at least one intake valve, when knocking occurs in at least one cylinder by actuation of the intake valve associated with the cylinder detected as knocking, in such a way that the temperature of the charge of the cylinder detected as knocking is reduced, the knocking in the cylinder is reduced, on actuating the intake valve associated with the cylinder detected as knocking, a cylinder-specific and/or a global measure for power compensation of the internal combustion engine is performed.

A controller for an internal combustion engine includes processing circuitry. The processing circuitry is configured to execute an estimation process that estimates a density parameter of fuel in an upper layer portion of a delivery pipe and a density parameter of fuel in a lower layer portion of the delivery pipe and an operation process that includes acquiring a density parameter of the fuel injected from a fuel injection valve and operating an operation unit of the internal combustion engine based on the acquired density parameter. The estimation process includes a process that assumes that when the density of the fuel flowing into the delivery pipe is high, a greater proportion of the fuel flowing into the delivery pipe flows into the lower layer portion than when the density of the fuel flowing into the delivery pipe is low.

A control system of a Miller cycle engine includes an ECU. The ECU executes an early closing Miller cycle operating mode in which a variable valve mechanism is controlled to close an intake valve before an intake bottom dead center. The ECU executes a decompression mode in which the variable valve mechanism is controlled to close the intake valve at a point later than the intake BDC, when the engine is started. The electronic control unit executes the early closing Miller cycle operating mode after completion of the decompression mode. A later closing amount of the intake valve relative to the intake BDC, for use in the decompression mode, is larger than an early closing amount of the intake valve relative to the intake BDC when the closing timing of the intake valve is most advanced.

An operating range boundary for switching a cam for driving an intake valve (drive cam) is changed in a direction of increasing an engine load if a target EGR rate is predicted to increase across the contour line of the EGR rate during an acceleration operation. By changing to such a high load direction, a range in which a large cam is selected is enlarged. That is, switching of the drive cam from the large cam to a small cam is delayed.