Cylinder block with integrated oil jacket

A method of manufacturing an engine block, the method comprising:

• providing a mold for the engine block, the mold including a plurality of cylinder barrel core sections coupled together, each cylinder barrel core section in the plurality of cylinder barrel core sections including at least one curved protrusion protruding radially outward from a cylinder barrel core wall and extending about at least a portion of a circumferential portion of the cylinder barrel core section;
• and
• casting a molten material in the mold and about the plurality of cylinder barrel core sections such that an engine block is formed having a plurality of cylinder barrels and at least one oil jacket channel, the at least one oil jacket channel including a plurality of curved channel sections, each curved channel section in the plurality of curved channel sections formed directly on at least a portion of a circumferential portion of an inner surface of a respective cylinder barrel in the plurality of cylinder barrels, wherein the at least one oil jacket channel extends between adjacent cylinder barrels of the plurality of cylinder barrels in the engine block.