The invention discloses an engine and an engine body. The engine body comprises a cylinder body with multiple cylinder holes, a water distribution cavity is formed in the cylinder body, a water jacketis arranged in the side wall between two adjacent cylinder holes, and communicates with the water distribution hole, the bottom end face of the water jacket is provided with a protruding structure, the height of the protruding structure is smaller than the height of the water jacket by one half, a supporting beam is arranged in the water jacket, the two ends of the supporting beam are fixedly connected with the two side walls of the water jacket, the supporting beam can improve rigidity of the cylinder holes, deforming of the cylinder holes in the crankshaft axis direction can be restrained,and reliability is improved; the height of the protruding structure is reduced, the lower area of the water jacket is reduced, appearing of a dead water area is avoided, the flow speed is improved, the heat exchange coefficient is increased, in the casing production transport process, storage is easy, and the casting difficulty and the rejection rate are reduced; and on the basis of the structure,when the cylinder diameters are same, the cylinder centre distance of the engine is small, the whole length is small, and competitive power of a product is improved.