Cooling structure of multi-cylinder engine

A cooling structure of a multi-cylinder engine having a cylinder block formed with a plurality of cylinders and a cylinder bore wall of the plurality of cylinders, the cylinder block being fastened to a cylinder head, the cooling structure comprising:

• a water jacket formed in the cylinder block and defined by the cylinder bore wall and a jacket outer surface surrounding the cylinder bore wall;
• a water pump for feeding a coolant to the water jacket by being driven by the engine;
• an introduction portion formed in the cylinder block, having an introduction port opening to the jacket outer surface, and for introducing, to the water jacket, the coolant fed by the water pump;
• and
• a spacer member accommodated inside the water jacket,
• wherein the spacer member has a spacer main body surrounding the cylinder bore wall, and a dividing wall protruding toward the jacket outer surface from an outer circumferential surface of the spacer main body,
• wherein the dividing wall extends in a circumferential direction of the spacer main body to a position proximate the introduction port,
• wherein the dividing wall extends out from the position proximate the introduction port so as to run facing the outer circumferential surface of the spacer main body and demarcate a cylinder head side space and a counter cylinder head side space on a side opposite from the cylinder head,
• wherein the cylinder head side space is adjacent to the introduction port and provided above the dividing wall and adjacent to the outer circumferential surface of the spacer main body, and
• wherein the counter cylinder head side space is adjacent to the introduction port and provided below the dividing wall.