8973861890 Excavator 4HK1 Engine Parts Camshaft Metal

Part number 8973861890 is the original camshaft provided by ISUZU (Isuzu) for the 4HK1 series diesel engine. This component is the core of the engine valve system, used to precisely control the opening and closing timing and lift of the intake and exhaust valves. Its universal models cover various mainstream medium-sized hydraulic excavators equipped with 4HK1 engines, mainly including Hitachi ZX200-3, ZX240-3, ZX210LC-3, Shengang SK200-8, SK210LC-8, as well as Sumitomo SH210-5, SH240-5 and other 20-24 ton models. As the core moving parts of the original factory, all cam profiles, journal diameters, phase angles are precisely matched with the engine cylinder head, valves, and timing system

This product is a high-strength alloy steel integral forged camshaft, with a long axis shape and a silver gray surface. After precision grinding, it presents a uniform brushed texture. There are multiple peach shaped cams (intake cam and exhaust cam) distributed on the shaft, and the profile of each cam is precisely designed to ensure the optimal opening and closing law of the valve. The shaft body is equipped with multiple support journals for rotation in the cylinder head bearing seat. One end is usually machined with locating pin holes and threaded holes for installing timing gears. Its material is usually 20CrMnTi or 42CrMo, which has undergone carburizing quenching and precision grinding. The surface hardness of the cam and journal reaches HRC 58-62, and the core maintains toughness, ensuring extremely high wear resistance and bending fatigue strength under high speed and high load.

Installation specifications (key process for engine overhaul): 1 Thoroughly clean: Before installation, all camshaft bearing seat holes and oil passages on the engine cylinder head must be thoroughly rinsed with specialized cleaning agents and high-pressure air, and wiped clean with a lint free cloth. 2. Lubrication: Apply sufficient engine assembly lubricant or clean engine oil to all shaft necks, cam surfaces, and cylinder head bearing seats. 3. Smooth insertion: Place the camshaft smoothly and horizontally into the bearing seat, avoiding collision with the camshaft and shaft neck. 4. Torque tightening: When installing the camshaft bearing cover (tile cover), it is necessary to cross tighten it 2-3 times according to the order specified in the maintenance manual (usually from the middle to both ends) and the torque value (usually 20-30 N · m).