Cylinder head structure in multi-cylinder engine

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is defined within a cylinder head and comprised of a plurality of exhaust port sections extending from a plurality of exhaust valve bores opening to each of a plurality of combustion chambers arranged along a cylinder array, said plurality of exhaust port sections being integrally collected together to form a collected area and said collected areas from the respective combustion chambers being collected together into an exhaust collecting section within said cylinder head, wherein said structure includes a protrusion provided on a side surface of said cylinder head to project outside a side surface of a cylinder block to which said cylinder head is coupled, said protrusion projecting outwards in a largest amount while defining said exhaust collecting section therein, wherein said cylinder head includes a spark plug insertion tube located above the collecting exhaust port and inclined toward said exhaust collecting section with respect to a cylinder axis, said spark plug insertion tube being connected with an upper surface of said protrusion by a reinforcing wall.

A cylinder head structure in a multi-cylinder engine having a cylinder head, comprising a collecting exhaust port which includes an exhaust collecting section within said cylinder head, said exhaust collecting section being formed by integrally collecting a plurality of exhaust port sections extending from a plurality of combustion chambers arranged along a cylinder array, wherein an ignition coil is disposed directly above said exhaust collecting section and a water jacket is disposed directly above said exhaust collecting section and between said exhaust collecting section and said ignition coil as viewed in the direction perpendicular to a cylinder axis.

A cylinder head structure in a multi-cylinder engine having a cylinder head and a cylinder block, comprising a collecting exhaust port which includes an exhaust collecting section within said cylinder head, said exhaust collecting section being formed by integrally collecting a plurality of exhaust port sections extending from a plurality of combustion chambers arranged along a cylinder array, wherein a protrusion is provided on a side surface of said cylinder head so as to project outside a side surface of said cylinder block, thereby defining the most projected part of said exhaust collecting section, and wherein a spark plug insertion tube is provided in said cylinder head at an inclination with respect to a cylinder axis and is positioned directly above said exhaust collecting section as viewed in the direction perpendicular to said cylinder axis, said spark plug insertion tube being connected to an area of said protrusion having said exhaust collecting section defined therein via a reinforcing wall.

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is comprised of a plurality of exhaust port sections extending from a plurality of exhaust valve bores arranged along a cylinder array, respectively, with a generally elongated wall portion disposed between consecutive ones of the exhaust port sections and associated exhaust valve bores and integrally collected together in an exhaust collecting section defined within a cylinder head, wherein said structure includes a protrusion having an arch-shaped side surface of said cylinder head to project outside a side surface of a cylinder block to which said cylinder head is coupled, said protrusion projecting outwards in a largest amount in said exhaust collecting section with an exhaust outlet formed generally centrally therein, wherein said cylinder head includes a spark plug insertion tube, a water jacket is interposed between an ignition coil mounted in an opening at an upper end of said spark plug insertion tube and said collecting exhaust port.

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is comprised of a plurality of exhaust port sections extending from a plurality of exhaust valve bores arranged along a cylinder array, respectively, with a generally elongated wall portion disposed between consecutive ones of the exhaust port sections and associated exhaust valve bores and integrally collected together in an exhaust collecting section defined within a cylinder head, wherein said structure includes a protrusion having an arch-shaped side surface of said cylinder head to project outside a side surface of a cylinder block to which said cylinder head is coupled, said protrusion projecting outwards in a largest amount in said exhaust collecting section with an exhaust outlet formed generally centrally therein, wherein said cylinder head includes a spark plug insertion tube inclined toward said exhaust collecting section with respect to a cylinder axis, said spark plug insertion tube being connected with an upper surface of said protrusion by a reinforcing wall.

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is comprised of a plurality of exhaust port sections extending from a plurality of exhaust valve bores arranged along a cylinder array, respectively, with a generally elongated wall portion disposed between consecutive ones of the exhaust port sections and associated exhaust valve bores and integrally collected together in an exhaust collecting section defined within a cylinder head, wherein said structure includes a protrusion having an arch-shaped side surface of said cylinder head to project outside a side surface of a cylinder block to which said cylinder head is coupled, said protrusion projecting outwards in a largest amount in said exhaust collecting section with an exhaust outlet formed generally centrally therein, oil passages which are defined in regions surrounded by said exhaust collecting section and a pair of said exhaust port sections extending from adjacent ones of said combustion chambers.

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is comprised of a plurality of exhaust port sections extending from a plurality of exhaust valve bores arranged along a cylinder array, respectively, with a generally elongated wall portion disposed between consecutive ones of the exhaust port sections and associated exhaust valve bores and integrally collected together in an exhaust collecting section defined within a cylinder head, wherein said structure includes a protrusion formed on a side surface of said cylinder head to project in an arch shape outside a side surface of a cylinder block to which the cylinder head is coupled.

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is comprised of exhaust port sections extending from a plurality of exhaust valve bores arranged along a cylinder array, respectively, with a generally elongated wall portion disposed between consecutive ones of the exhaust port sections and associated exhaust valve bores and integrally collected together in an exhaust collecting section defined within a cylinder head, wherein said structure includes a protrusion formed on a side surface of said cylinder head to project in an arch shape outside a side surface of a cylinder block to which the cylinder head is coupled, wherein a water jacket is provided above said exhaust collecting section so as to extend outwardly of said side wall defining said valve operating chamber.

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is defined within a cylinder head and comprised of a plurality of exhaust port sections extending from a plurality of exhaust valve bores opening to each of a plurality of combustion chambers arranged along a cylinder array, said plurality of exhaust port sections being integrally collected together to form a collected area and said collected areas from the respective combustion chambers being collected together into an exhaust collecting section within said cylinder head,

• wherein said structure includes a protrusion provided on a side wall of said cylinder head defining a valve operating chamber therein so as to project outside a side surface of a cylinder block to which said cylinder head is coupled, said protrusion projecting outwards in a largest amount while defining said exhaust collecting section therein, and a water jacket is defined in at least one of an upper surface and a lower surface of said exhaust collecting section so as to extend outwardly of said side wall defining said valve operating chamber.

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is comprised of exhaust port sections extending from a plurality of combustion chambers arranged along a cylinder array, respectively, and integrally collected together in an exhaust collecting section defined within a cylinder head, wherein said structure includes a protrusion formed on a side surface of said cylinder head to project in an arch shape outside a side surface of a cylinder block to which the cylinder head is coupled and have an outermost side wall, and said exhaust collecting section is formed to extend outwardly of a side wall of said cylinder head defining a valve operating chamber and no water jacket is interposed between said side wall of said protrusion and said exhaust collecting section.

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is comprised of exhaust port sections extending from a plurality of combustion chambers arranged along a cylinder array, respectively, and integrally collected together in an exhaust collecting section defined within a cylinder head, wherein said structure includes a protrusion provided on a side surface of a cylinder head to project outside a side surface of a cylinder block to which said cylinder head is coupled, said protrusion projecting outwards in a largest amount in said exhaust collecting section, and a water jacket of a flat shape defined in at least one of an upper surface and a lower surface of said exhaust collecting section.

A cylinder head structure in a multi-cylinder engine having a cylinder head, comprising a collecting exhaust port which is defined within said cylinder head and comprised of a plurality of exhaust port sections extending from a plurality of exhaust valve bores opening to each of a plurality of combustion chambers arranged along an array of a plurality of cylinders, said plurality of exhaust port sections being integrally collected together to form a collected area and said collected areas from the combustion chambers of adjacent ones of said cylinders being collected together into an exhaust collecting section within said cylinder head, wherein said collecting exhaust port has a downstream end opening that is formed into an elliptical shape elongated in the direction of the cylinder array.

A cylinder head structure in a multi-cylinder engine, comprising a collecting exhaust port which is defined within a cylinder head and comprised of a plurality of exhaust port sections extending from a plurality of exhaust valve bores opening to each of a plurality of combustion chambers arranged along a cylinder array, said plurality of exhaust port sections being integrally collected together to form a collected area and said collected areas from the respective combustion chambers being collected together into an exhaust collecting section within said cylinder head, wherein said structure includes a protrusion provided on a side surface of said cylinder head to project outside a side surface of a cylinder block to which said cylinder head is coupled, said protrusion projecting outwards in a largest amount while defining said exhaust collecting section therein and, oil passages which are defined in regions each surrounded by said exhaust collecting section and two of said exhaust port sections extending from adjacent ones of said combustion chambers.

A cylinder head structure in a multi-cylinder engine having a cylinder head, comprising a collecting exhaust port which includes an exhaust collecting section within said cylinder head, said exhaust collecting section being formed by integrally collecting a plurality of exhaust port sections extending from a plurality of combustion chambers arranged along an array of a plurality of cylinders, wherein an oil passage is provided in a partition wall defined and surrounded by said exhaust port sections extending from said combustion chambers of adjacent ones of said cylinders and by said exhaust collecting section.