An engine is provided, which includes an engine body including a cylinder provided with intake and exhaust ports and intake and exhaust valves, intake and exhaust passages, a turbocharger including a turbine provided to the exhaust passage and a compressor provided to the intake passage, and a variable phase mechanism configured to change open/close timings of the intake valve while maintaining an open period of the intake valve at a 270° C.A or larger. A geometric compression ratio of the cylinder is 11:1 or higher. In a high-load range, the variable phase mechanism sets the intake valve close timing to be after an intake BDC and to make a ratio of a retarded amount of the intake closing to the geometric compression ratio be 4.58 or above and 6.67 or below, and sets the intake valve open timing to be before a close timing of the exhaust valve.

A variable-lift valve train for a gas exchange valve of an internal combustion engine includes a lift adjuster, a lift actuator, and a lift lever. The lift adjuster has a working curve that is arrangeable at least in a first working position for setting a partial lift and in a second working position for setting a maximum lift. The working curve has a lift region and a base circle region. The lift actuator, which has an actuating contour configured to deflect the lift adjuster. The lift lever, which is deflectable via the working curve and thereby actuates a lift of the gas exchange valve. The valve train is configured to, in the first working position and in the second working position, actuate the gas exchange valve with an at least substantially equal maximum valve acceleration.

An engine system comprising an internal combustion engine and a turbocharger, where a diameter of the at least one intake valve is greater than a diameter of the at least one exhaust valve, the salient angle of the piston bowl is at least 10 degrees, the ratio between the piston bowl opening diameter and the piston bowl depth is approximately 0.5 to 2.0, the intake valve opens before top dead center on an exhaust stroke of the internal combustion engine and closes before bottom dead center of an intake stroke of the internal combustion engine, and the turbocharger has a combined efficiency of more than 50%.

An internal combustion engine for a motor vehicle includes a combustion chamber with a gas exchange valve which is movable between an open position and a first closed position. The gas exchange valve is movable on its path from the open position in a direction of the first closed position into an intermediate position located between the open position and the first closed position and is holdable in the intermediate position at least during a part of a compression cycle of the combustion chamber following the open position of the gas exchange valve and is movable into a second closed position following the intermediate position. The part comprises more than a half of the compression cycle and less than a whole of the compression cycle. The gas exchange valve is an inlet valve via which the combustion chamber is supplyable at least with air.

Methods and systems are provided for a prechamber. In one example, the prechamber comprises one or more valves for optionally adjusting gas flow therethrough. The one or more valves may allow pre-chamber and combustion chamber settings to be modified, thereby enhancing combustion operating parameters.

Operating a direct-injection compression-ignition engine includes injecting early pilot shots of fuel, and controlling a cylinder temperature timing to combust the early pilot shots according to a combustion phasing that is based on the cylinder temperature timing. A main charge of the fuel is combusted based on the combustion of the early pilot shots. A combustion control unit is structured to command actuation of a fuel injector and a cylinder temperature controller to phase combustion of early pilot shots of the fuel, prior to a TDC position of a piston in an engine cycle. The cylinder temperature controller is a variable valve actuator or other apparatus controlling cylinder temperature in a manner decoupled from piston position.

An internal combustion engine of reciprocating-piston type of construction is described which has a cylinder (2) with a cylinder head (1) and with an inlet valve (3) arranged in the cylinder head. An inlet line (4) is connected to the inlet valve (3), via which inlet line combustion air (5) can be fed to the cylinder (2). Furthermore, a compressed-air accumulator (6) is provided which is connected to the inlet line (4) by means of a controllable valve (7), wherein the inlet line (4) can be closed, with regard to its throughflow cross section, by means of a shut-off element (8). The valve (7) is controllable such that, on the basis of a control signal, compressed air (9) is fed from the compressed-air accumulator (6) into a region of the inlet line directly upstream of the inlet valve (3), wherein the shut-off element (8) is arranged sealingly on the cylinder head (1) and closes the cross section of the inlet line (4). The inlet valve (3) is briefly re-opened by means of an actuation element (24) during the compression stroke, and during said brief re-opening, compressed air (9) is fed from the compressed-air accumulator (6) into the cylinder (2), with the shut-off element (8) being held in its closed position. According to a second aspect, the compressed-air accumulator (6) can also be used to feed all of the combustion air to the cylinder (2) via an inlet reservoir (25) directly upstream of the inlet valve (3).

The invention relates to a method for operating an internal combustion engine, which has an internal combustion motor, which forms at least two combustion chambers, which are bounded by cylinders formed in a cylinder housing and by pistons guided up and down cyclically in said cylinders and in which thermodynamic cycles can be performed during operation of the internal combustion engine, wherein then a gas exchange in the combustion chambers is controlled by means of at least one intake valve (28) and one exhaust valve in the case of each combustion chamber, which valves are actuated by means of cams, and wherein a first operating state is provided, in which the thermodynamic cycles are performed both in a first combustion chamber and in a second combustion chamber and a second operating state is provided, in which the thermodynamic cycles are performed in the first combustion chamber and the thermodynamic cycles are not performed in the second combustion chamber, is characterized in that, in order to switch from the first operating state to the second operating state, a switch is made from the use of a first intake cam to the use of a second intake cam for the actuation of the intake valve associated with the first combustion chamber. Such a method makes it possible to realize a switchover from full operation to partial operation in manner that is as torque-neutral as possible in that the torque component that ceases because of the deactivation of the cylinder or cylinders provided therefor is compensated by the one or more cylinders that continue to actively operate, at least also in that, in the event of the switchover, the delivery ratio, i.e. the ratio of the mass of fresh gas actually contained in the cylinder after the conclusion of a charge cycle to the theoretical maximum possible mass, is increased for said cylinders and, in particular, is set as high as possible.

The invention relates to an internal combustion engine comprising a crankshaft, one or more cylinders including a cylinder head, a piston, a combustion chamber, one or more intake valves, one or more exhaust valves, an intake system configured for feeding intake air to the engine, an exhaust system configured for conveying exhaust gas away from the engine, a pressure charging system connected to the intake system and an exhaust gas recirculation (EGR) system arranged to feed branched off exhaust gas from the exhaust system to the intake system via an EGR conduit wherein: * the internal combustion engine includes a valve actuation device configured to allow for late or early closing of the intake valves in accordance with late or early Miller-type valve timing, and wherein * the EGR system includes a gas feeding device configured to feed exhaust gas through the EGR conduit in modes of operation wherein the pressure in the intake system exceeds the pressure in the exhaust system, * wherein the gas feeding device is a displacement pump and wherein the gas feeding device is arranged so that exhaust gas recirculating in the EGR system during operation of the engine passes the gas feeding device before being mixed with intake air in the intake system. Additionally, a method of improving efficiency of an internal combustion engine is described.

In certain embodiments, Lube Oil Controlled Ignition (LOCI) Engine Combustion overcomes the drawbacks of known combustion technologies. First, lubricating oil is already part of any combustion engine; hence, there is no need to carry a secondary fuel and to have to depend on an additional fuel system as in the case of dual-fuel technologies. Second, the ignition and the start of combustion rely on the controlled autoignition of the lubricating oil preventing the occurrence of abnormal combustion as experienced with the Spark Ignition technology. Third, LOCI combustion is characterized by the traveling of a premixed flame; hence, it has a controllable duration resulting in a wide engine load-speed window unlike the Homogeneous Charge Compression Ignition technology where the engine load-speed window is narrow. Adaptive Intake Valve Closure may be used to control in-cylinder compression temperature to be high enough to realize the consistent auto ignition of the lubricating oil mist.