WATER JACKET CORE

摘要

A water jacket core (10) includes a base part (11) and is provided with an intermediate female thread part (15) in that base within a region surrounded by tangent lines (18, 19) that are parallel to a center line (17) passing through the centers of a plurality of bore pin insertion holes (12) for forming cylinder bores and are in contact with the bore pin insertion holes and by an intermediate position for the adjacent bore pin insertion holes.