Patent ID: 8919302

Claim:
A cooling structure for an internal combustion engine, in which: a spacer is fitted inside a water jacket which is formed to surround peripheries of a plurality of cylinder bores arranged one after another on a cylinder row line of a cylinder block of the internal combustion engine; and a cooling condition of the cylinder bores is controlled by regulating a flow of cooling water in the water jacket by use of the spacer, wherein the spacer comprises a spacer main body surrounding the peripheries of the cylinder bores and a fixing part projecting from said spacer main body in a cylinder-axis line direction, wherein the fixing part fixes the spacer inside the water jacket; wherein the fixing part is configured such that it is thinner in a radial direction than a thickness of the spacer, such that the influence of the fixing part on the flow of the cooling water is small; wherein the fixing part extends upwardly from an upper end face of the spacer main body or downwardly from a lower end face of the spacer main body in the cylinder-axis line direction; and wherein the fixing part extends partly in a direction peripheral to the cylinder bores so as to permit flow of cooling water between an inner wall surface and an outer wall surface of the water jacket.