ENGINE HAVING WATER JACKET

An engine having a water jacket may include a cylinder block in which cylinder liners forming a combustion chamber may be disposed from a first end to a second end of the cylinder block, and a block water jacket may be formed around the cylinder liners, a cylinder head having a head water jacket coupled to a top of the cylinder block, receiving cooling water from an exhaust side of the block water jacket and discharging cooling water to an intake side of the block water jacket, and inserts that may be inserted into the block water jacket and that may have horizontal dividing blades dividing the block water jacket into upper and lower parts, legs extending downward from the horizontal dividing blades, and flow preventing protrusions protruding upward from the horizontal dividing blades to divide the upper part of the block water jacket.