Patent ID: 7849683
Filing Date: 2010-12-14
Classification: F02F

Abstract:
1. A multiple-cylinder internal combustion engine comprising: a cylinder block provided with a predetermined number of cylinders not less than two cylinders arranged in a predetermined cylinder arranging direction; and a cylinder head attached to the cylinder block so as to form combustion chambers respectively corresponding to the cylinders, said cylinder head having exhaust ports respectively opening into the combustion chambers for being opened and closed by exhaust valves, respectively, individual exhaust passageways respectively connected to the exhaust ports such that the exhaust gas discharged through the exhaust ports flows through the individual exhaust passageways, and a central collecting passageway for collecting the exhaust gas from the individual exhaust passageways; wherein each of the individual exhaust passageways has a plurality of branch passageways connected to the exhaust ports opening into the combustion chamber and to be opened and closed by the exhaust valves, and a merging passageway having an upstream end joined to the plurality of branch passageways, the merging passageway has a passage diameter substantially equal to that of the branch passageways, and the merging passageway and the central collecting passageway are surrounded by water jackets from above and below.