A cylinder head for an internal combustion engine is disclosed having an intake port geometry configured to reduce fuel puddling and improve fuel atomization. The cylinder head includes a housing having a recess defining a top portion of a combustion chamber. The cylinder head further includes intake and exhaust ports defined by channels extending from the top portion of the combustion chamber to an outer end of the housing. An intake valve is positioned within the cylinder head to control communication of the intake port with the combustion chamber, and an exhaust valve is positioned within the cylinder head to control communication of the exhaust port with the combustion chamber. The intake port further includes a cross-section having a modified D-shape with a single 90 degree corner. The modified D-shape cross-section extends substantially a length of the intake port.

A cylinder head for an internal-combustion engine includes, for each cylinder of the engine, at least one intake duct extending from an inlet located at a lateral face of the head down to an outlet cylindrical mouth and an intake valve associated with each intake duct. The surface of the intake duct has a longitudinal projection for deflecting the flow of air that flows through the intake duct. The projection is configured to provide a deflection of the air flow towards the two sides of the valve stem, so as to substantially reduce the quantity of air that hits the valve stem directly. The projection extends down to the outlet cylindrical mouth, so as to hinder a flow of air through an angular sector of the cross-sectional area of the outlet mouth which angular sector faces towards the lateral face of the cylinder head.

In an upstream portion from a valve connecting surface that is formed in an opening of an intake port to a combustion chamber, an upper wall surface of the intake port continues from an upstream side end of the valve connecting surface and extends substantially straight and diagonally with respect to a ceiling surface on the intake port side. In addition, a cross-sectional shape of the portion in the intake port in a direction perpendicular to an axial direction of the intake port is a flat shape with an axis in a transverse direction being a long axis.

A moment-cancelling, four-stroke engine is disclosed. The engine includes a first cylinder having a first piston and a second cylinder having a second piston, a first crankshaft operably connected to the first piston and a second crankshaft operably connected to the second piston. The first crankshaft rotates in a first direction and the second crankshaft rotates in a second direction that is opposite the first direction to cancel the moments applied to the engine and reduce engine vibration.

One exemplary embodiment of the present disclosure relates to an engine intake port structure. According to the engine intake port structure of the exemplary embodiment of the present disclosure, a chamfer is formed to be offset to either side from an end corner of an intake port. Accordingly, the inflow of a fuel gas is concentrated on a side in which an opening width of the chamfer is wide at the beginning of an opening stage when the intake port is opened/closed by a valve unit, and after the intake port is opened, the opening width is formed to be similar at four sides of the valve unit such that swirls formed in the fuel gas is weakened. That is, complete combustion of the fuel can be anticipated since the length of time during which the fuel gas remains in a combustion chamber is extended.

This multi-cylinder engine intake structure is provided with a fresh air distribution chamber into which a plurality of fresh air distribution openings communicating with the individual intake ports are opened, and a gas collection chamber. The gas collection chamber includes a communication region into which a first communication opening communicating with the fresh air distribution chamber is opened, a first mixture region into which an air inlet and an EGR gas inlet are opened and which is positioned upstream of the communication region in a flow direction of a mixture gas of air and EGR gas, and a second mixture region positioned downstream of the communication region in the flow direction of the mixture gas.

The invention relates to a cylinder head (10) for a combustion engine, where the cylinder head (10) comprises one or more gas channels (18a, 18b) with a gas connection (20) to receive gas and which is connected with one or more valves (14,16) for control of gas supply and gas admission, where said one or more valves (14,16) are fitted on or in the cylinder head (10). The cylinder head (10) comprises an internal gas channel (18a, 18b) that runs from the gas connection (20) and internally in the cylinder head (10) to said one or more valves (14,16). Also described is a method for supply of prechamber gas in a cylinder head (10) belonging to a combustion engine, in which gas is led through an internal boring (22) that is connected with a gas channel (18a) integrated internally in the cylinder head (10), where the internal boring (22) runs into an prechamber (26) in the cylinder head (10).

A cylinder head of a multi-cylinder engine is provided, the cylinder head including a plurality of ceiling parts for respective cylinders, and a water jacket. Each ceiling part is connected to an intake port including a primary port and a secondary port aligned in a cylinder-row direction, and is attached with an in-cylinder pressure sensor. A plug is attached to a hollow part of the cylinder head corresponding to a core print provided to a core of the water jacket, and is disposed at a position corresponding to a location between certain cylinders. The in-cylinder pressure sensor is attached at a position on an opposite side from the plug with respect to a cylinder center axis in the cylinder-row direction. Positions of the primary and secondary ports connected to each ceiling part are interchanged in the cylinder-row direction according to the position of the in-cylinder pressure sensor.

The present invention relates to a gas intake device (1) for a cylinder of an internal-combustion engine. The gas intake device comprises two intake pipes (5a, 5b), two intake valves (4), two intake valve calibration parts (6a, 6b) and, in each intake pipe (5a, 5b), means for forming an aerodynamic gas motion of tumble type in the cylinder. Furthermore, for each intake pipe (5a, 5b), the intersection between intake pipe (5a, 5b) and calibration part (6a, 6b) occurs along a line non-parallel to the plane of the fire face. Besides, the inclination angle of this intersection is different for each pipe (5a, 5b).

The present invention relates to a gas inlet device (1) for a cylinder of an internal combustion engine. The gas inlet device (1) comprises an inlet port (5), an inlet valve (4), a calibration (6) of the inlet valve (4), means for forming a tumble-type aerodynamic movement of the gas in the cylinder, and a mask (10). Furthermore, the intersection (7) between the inlet port (5) and the calibration (6) is along a straight line not parallel to the plane of the firing face (FF). In addition, the mask (10) is oriented in the same way as the end of the inlet port (5).