An engine includes a cylinder block, a cylinder head, and a piston. The cylinder head is connected to the cylinder block. The piston is movably connected to the cylinder block. The cylinder block, the cylinder head, and the piston form a combustion chamber. The cylinder head includes an intake valve hole and an exhaust valve hole. An intake valve is disposed at the intake valve hole and an exhaust valve is disposed at the exhaust valve hole. A barrier protrusion is protruded at the edge of the intake valve hole away from the exhaust valve hole. The included angle between a first connecting line connecting a first end of the barrier protrusion and a center of the intake valve hole and a second connecting line connecting a second end of the barrier protrusion and the center of the intake valve hole is greater than 120 degrees and less than or equal to 180 degrees.