A gasoline compression ignition engine is operated in two modes. In a one mode of operation the engine is operated with a firing fraction of one, corresponding to all of the cylinders being active, working cylinders. In a second skip fire mode of operation a firing fraction of less than one may be used under conditions, such as a low load condition, to improve efficiency. The skip fire mode of operation may also be selected in part based on other considerations, such as maintaining an exhaust temperature conducive for efficient catalytic converter operation or limiting cylinder output variability.

A gasoline compression ignition engine is operated in two modes. In a one mode of operation the engine is operated with a firing fraction of one, corresponding to all of the cylinders being active, working cylinders. In a second skip fire mode of operation a firing fraction of less than one may be used under conditions, such as a low load condition, to improve efficiency. The skip fire mode of operation may also be selected in part based on other considerations, such as maintaining an exhaust temperature conducive for efficient catalytic converter operation or limiting cylinder output variability.

A combustion system is provided for an internal combustion engine including a cylinder head and a piston. In one example, a combustion system may include a cylinder head with a second cylinder surface angled relative to a first cylinder surface, an intake port coupled to the first cylinder surface, an exhaust port coupled to the second cylinder surface, and a piston with a first piston surface parallel to the first cylinder surface and a second piston surface parallel to the second cylinder surface.

A combustion system is provided for an internal combustion engine including a cylinder head and a piston. In one example, a combustion system may include a cylinder head with a second cylinder surface angled relative to a first cylinder surface, an intake port coupled to the first cylinder surface, an exhaust port coupled to the second cylinder surface, and a piston with a first piston surface parallel to the first cylinder surface and a second piston surface parallel to the second cylinder surface.

A compressor capable of generating a swirling flow at a sufficient speed with respect to a main flow of intake air that flows into a compressor impeller without hindering the main flow. The compressor includes a compressor impeller, a shroud covering a tip end edge of the impeller, an intake duct extending along an axial direction of the impeller, a swirling flow passage being annular around a rotating shaft and having a flow passage cross-sectional area that gradually decreases along the same direction as a rotation direction of the impeller from a base end side where a swirling gas introduction portion is disposed toward a front end side, and a swirling gas ejection passage extending along a radial direction of the impeller. The swirling gas introduction portion is connected to a portion on a downstream side of the front edge portion of the impeller in the intake flow passage.

A compressor capable of generating a swirling flow at a sufficient speed with respect to a main flow of intake air that flows into a compressor impeller without hindering the main flow. The compressor includes a compressor impeller, a shroud covering a tip end edge of the impeller, an intake duct extending along an axial direction of the impeller, a swirling flow passage being annular around a rotating shaft and having a flow passage cross-sectional area that gradually decreases along the same direction as a rotation direction of the impeller from a base end side where a swirling gas introduction portion is disposed toward a front end side, and a swirling gas ejection passage extending along a radial direction of the impeller. The swirling gas introduction portion is connected to a portion on a downstream side of the front edge portion of the impeller in the intake flow passage.

An inlet duct, an induction system, and a system are disclosed for directing an inlet flow into an inlet compressor for use in an internal combustion engine. An example inlet duct may include one or more relief features disposed on an inner surface of the inlet duct. The one or more relief features may be made integral with the inlet duct. The one or more relief features may be disposed to protrude into the inlet flow to cause the inlet flow to swirl before reaching the inlet compressor.

An inlet duct, an induction system, and a system are disclosed for directing an inlet flow into an inlet compressor for use in an internal combustion engine. An example inlet duct may include one or more relief features disposed on an inner surface of the inlet duct. The one or more relief features may be made integral with the inlet duct. The one or more relief features may be disposed to protrude into the inlet flow to cause the inlet flow to swirl before reaching the inlet compressor.

An exhaust-gas turbocharger (1) with a compressor wheel (2); with a turbine wheel (3); and with a shaft (4) on which the compressor wheel (2) and the turbine wheel (3) are arranged in a rotationally secured manner. The turbine wheel (3) has a through-opening (5) in which a first end region (6) of the shaft (4) is arranged, and the turbine wheel (3) is braced between an end-side stop (7) connected to the end region (6) and a compressor wheel-side shaft sleeve (8) fixed on the shaft (4).

An exhaust-gas turbocharger (1) with a compressor wheel (2); with a turbine wheel (3); and with a shaft (4) on which the compressor wheel (2) and the turbine wheel (3) are arranged in a rotationally secured manner. The turbine wheel (3) has a through-opening (5) in which a first end region (6) of the shaft (4) is arranged, and the turbine wheel (3) is braced between an end-side stop (7) connected to the end region (6) and a compressor wheel-side shaft sleeve (8) fixed on the shaft (4).