CYLINDER BLOCK FOR ENGINE

PURPOSE:To improve thermal conductivity, output ability and durability by providing a ring-like copper alloy thick portion which is connected to a cylinder block main body and a liner through intermetallic connection, and has a surface abutting a metal part. CONSTITUTION:A cylinder block 1 is composed of an aluminum-alloy cylinder block main body 11, a cast iron liner 12 cast separately from an upper end of the cylinder block main body 11 while forming a bore 10, and a ring-like thick portion having quadrapole sectional shape being formed on the upper end inner side thereof. The thick portion 13 is connected to an upper end 12a of the liner 12 at its inner side of the lower end face through intermetallic connection of Cu-Fe or the like, and is connected to an upper end 11a of the cylinder block 11 at its other portion of the lower end and outer peripheral surface through intermetallic connection of Cu-Al or the like. The thick portion 13 is made of copper alloy. The bore 10 is blocked with a cylinder head 3 through a gasket 2, while a piston 50 is reciprocable inside the bore 10.