STRUCTURE FOR INTRODUCING SECONDARY AIR INTO EXHAUST PASSAGE OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To enhance the after-burning properties of exhaust gas by enhancing a preheating effect of secondary air to be introduced structure for introducing secondary air into the exhaust passage of an internal combustion engine. SOLUTION: A secondary air introduction passage 23 is formed up for a cylinder head 1 along an exhaust port 5. Secondary air is fed with pressure by an air pump, and the flow-out port 23a of the passage 23 is so formed up that its blow-out direction is turned to the side of an exhaust valve 7. A water jacket 22 is formed up in a place between the passage 23 and upper part of the cylinder head 1.