1 473H-1003021 SEAT WASHER-INTAKE VALVE 2 473H-1007011BA VALVE-INTAKE 3 481H-1003023 VALVE PIPE 4 481H-1007020 VALVE OIL SEAL 5 473H-1007013 SEAT-VALVE SPRING LOWER 6 473H-1007014BA VALVE SPRING 7 473H-1007015 SEAT-VALVE SPRING UPPER 8 481H-1007018 VALVE BLOCK 9 473H-1003022 SEAT WASHER-EXHAUST VALVE 10 473H-1007012BA VALVE-EXHAUST 11 481H-1003031 BOLT-CAMESHAFT POSITION OIL PIPE 12 481H-1003033 WASHER-CYLINDER CAP BOLT 13 481H-1003082 CYLINDER HEAD BOLT-M10x1.5 14 481F-1006020 OIL SEAL-CAMSHAFT 30x50x7 15 481H-1006019 SENSOR-CAMSHAFT-SIGNAL PULLEY 16 481H-1007030 ROCKER ARM ASSY 17 473F-1006035BA CAMSHAFT-EXHAUST 18 473F-1006010BA CAMSHAFT-AIR INTAKE 19 481H-1003086 HANGER 20 480EC-1008081 BOLT 21 481H-1003063 BOLT-BEARING COVER CAMSHAFT 22-1 473F-1003010 CYLINDER HEAD 22-2 473F-BJ1003001 SUB ASSY-CYLINDER HEAD (473CAST IRON-SPARE PART ) 23 481H-1007040 HYDRAULIC TAPPET ASSY 24 481H-1008032 STUD M6x20 25 473H-1003080 GASKET-CYLINDER 26 481H-1008112 STUD M8x20 27 481H-1003062 BOLT HEXAGON FLANGE M6x30 30 S21-1121040 SEAL-FUEL NOZZLE Cylinder head The cover of the engine and the parts for sealing the cylinder, including water jacket, steam valve and cooling fin. The cylinder head is made of cast iron or aluminum alloy. It is not only the installation matrix of the valve mechanism, but also the sealing cover of the cylinder. The combustion chamber is composed of the top of the cylinder and piston. Many have adopted the structure of casting the camshaft support seat and tappet guide hole seat into one with the cylinder head. Most of the damage phenomena of cylinder head are the warping deformation of the sealing plane of cylinder head and cylinder hole (damaging the seal), the cracks in the seat holes of inlet and exhaust valves, the damage of spark plug installation threads, etc. In particular, the cylinder head poured with aluminum alloy has more consumption than cast iron because of its low material hardness, relatively poor strength and easy deformation and damage. 1. Working conditions and requirements of cylinder head The cylinder head bears the mechanical load caused by gas force and fastening the cylinder head bolts. At the same time, it also bears high thermal load due to contact with high-temperature gas. In order to ensure the good sealing of the cylinder, the cylinder head shall not be damaged or deformed. Therefore, the cylinder head should have sufficient strength and stiffness. In order to make the temperature distribution of the cylinder head as uniform as possible and avoid thermal cracks between the intake and exhaust valve seats, the cylinder head shall be well cooled. 2. Cylinder head material Cylinder heads are generally made of high-quality gray cast iron or alloy cast iron, while gasoline engines for cars mostly use aluminum alloy cylinder heads. 3. Cylinder head structure Cylinder head is a box part with complex structure. It is machined with inlet and exhaust valve seat holes, valve guide holes, spark plug mounting holes (gasoline engine) or fuel injector mounting holes (diesel engine). A water jacket, an air inlet and exhaust passage and a combustion chamber or a part of the combustion chamber are also cast in the cylinder head. If the camshaft is installed on the cylinder head, the cylinder head is also processed with cam bearing hole or cam bearing seat and its lubricating oil passage. The cylinder head of water-cooled engine has three structural forms: integral type, block type and single type. In a multi cylinder engine, if all cylinders share a cylinder head, the cylinder head is called an integral cylinder head; If there is one cover for every two cylinders or one cover for every three cylinders, the cylinder head is a block cylinder head; If each cylinder has a head, it is a single cylinder head. Air cooled engines are all single cylinder heads.