| 摘要 |
In a water-cooled four-cycle engine, an engine core including a cylinder block, a cylinder head and a first crankcase half body is formed as a unitary part cast integrally; a water jacket including a cylinder jacket and a head jacket is formed in the engine core; and a timing-belt chamber being adjacent to the cylinder jacket is provided in a side portion of the engine core. A first opening portion for forming a first semi-peripheral portion of the cylinder jacket on a side opposite from the timing-belt chamber by casting out is provided in a side surface of the cylinder block. Second and third opening portions for forming a second semi-peripheral portion of the cylinder jacket and the head jacket as well as the timing-belt chamber, respectively, by casting out are provided in an upper surface of the cylinder head. |
