An engine system which combines an internal combustion engine with a unique air-cooling system. The air-cooling system includes a cooling cylinder(s) which is disposed in the engine block. Input air is expanded through the cooling cylinder from the intake manifold directly to the exhaust manifold. No high compression or combustion takes place in the cooling cylinder. Heat from the cooling cylinder is transferred to the input air, and the heated air is then exhausted to the internal combustion engine exhaust stream where it is used to help power a turbocharger.

An engine system which combines an internal combustion engine with a unique air-cooling system. The air-cooling system includes a cooling cylinder(s) which is disposed in the engine block. Input air is expanded through the cooling cylinder from the intake manifold directly to the exhaust manifold. No high compression or combustion takes place in the cooling cylinder. Heat from the cooling cylinder is transferred to the input air, and the heated air is then exhausted to the internal combustion engine exhaust stream where it is used to help power a turbocharger.

Methods and systems are provided for merging recirculated exhaust gas (EGR) with fresh intake air in an intake passage. In one example, a method may include introducing EGR to the intake passage via an angled annular slot and flowing unmixed EGR and ambient air through an intake compressor inlet. Ambient air may flow to a center of the intake compressor while the EGR may flow along a periphery of the intake compressor inlet.

Methods and systems are provided for merging recirculated exhaust gas (EGR) with fresh intake air in an intake passage. In one example, a method may include introducing EGR to the intake passage via an angled annular slot and flowing unmixed EGR and ambient air through an intake compressor inlet. Ambient air may flow to a center of the intake compressor while the EGR may flow along a periphery of the intake compressor inlet.

An engine is equipped with an engine body, a turbocharger, an exhaust gas purifier, an exhaust communication pipe. The turbocharger is connected to the engine body. The exhaust gas purifier purifies exhaust gas discharged from the turbocharger. The exhaust communication pipe connects the turbocharger with the exhaust gas purifier. The exhaust communication pipe includes: a first connection member that is connected to the turbocharger, and a second connection member that connects the first connection member with the exhaust gas purifier. A downstream end portion of the first connection member has an inner peripheral face having a cross-section of a circular shape. An upstream end portion of the first connection member has an inner peripheral face having a cross-section of an abnormal-shape that is different from the inner peripheral face of the downstream end portion.

An engine is equipped with an engine body, a turbocharger, an exhaust gas purifier, an exhaust communication pipe. The turbocharger is connected to the engine body. The exhaust gas purifier purifies exhaust gas discharged from the turbocharger. The exhaust communication pipe connects the turbocharger with the exhaust gas purifier. The exhaust communication pipe includes: a first connection member that is connected to the turbocharger, and a second connection member that connects the first connection member with the exhaust gas purifier. A downstream end portion of the first connection member has an inner peripheral face having a cross-section of a circular shape. An upstream end portion of the first connection member has an inner peripheral face having a cross-section of an abnormal-shape that is different from the inner peripheral face of the downstream end portion.

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.

An asymmetric double-entry turbine is provided with a turbine housing that includes a first volute, a second volute and a turbine receiving bore. The first volute has a first exhaust gas inlet and a first exhaust gas outlet. The second volute has a second exhaust gas inlet and a second exhaust gas outlet. The turbine receiving bore is in fluid communication with the first exhaust gas outlet and the second exhaust gas outlet for conducting a flow of exhaust gas from the first exhaust gas outlet and the second exhaust gas outlet out in an axial direction. The first exhaust gas outlet has an angular opening amount of more than 180 degrees around the turbine receiving bore. The second exhaust gas outlet has an angular opening amount of less than 180 degrees around the turbine receiving bore.

An asymmetric double-entry turbine is provided with a turbine housing that includes a first volute, a second volute and a turbine receiving bore. The first volute has a first exhaust gas inlet and a first exhaust gas outlet. The second volute has a second exhaust gas inlet and a second exhaust gas outlet. The turbine receiving bore is in fluid communication with the first exhaust gas outlet and the second exhaust gas outlet for conducting a flow of exhaust gas from the first exhaust gas outlet and the second exhaust gas outlet out in an axial direction. The first exhaust gas outlet has an angular opening amount of more than 180 degrees around the turbine receiving bore. The second exhaust gas outlet has an angular opening amount of less than 180 degrees around the turbine receiving bore.