The disassembly and installation of the cylinder head of the excavator engine:
1 disassemble into the exhaust manifold.
2 for the top valve type engine, the valve chamber cover should be removed first, the bracket mounting bolt should be removed, and the rocker shaft and rocker arm should be removed under the installation condition.
3 in the opposite order of tightening the cylinder head bolts in the cylinder cover, each screw inspection is gradually loosened, and the bolts in one place are not allowed to be loosened completely at a time. The torque of the cylinder head bolts should be 0-12 kilograms.
4 after all the cylinder head screws are removed, the crankshaft is rotated by hand. When the compression pressure of the cylinder is applied, the cylinder gasket can easily leave the cylinder surface.
5 when the cylinder head is installed, apply the sealant on the cylinder pad and fasten the cylinder head to pick up the cylinder head, so that the cylinder pad can be prevented from warping (generally according to the order from the inside and the extrovert when it is loosened). When the cylinder head bolt is tightened, the bolt is tightened. If the cylinder pad breaks, the high-pressure gas is broken. It will enter the cooling water and cause overheating, and at the same time, the engine power will be reduced due to the leakage of the cylinder.
Cylinder heat
Cylinder gaskets should be made of materials that are resistant to high pressure and are not afraid of oil and water erosion. They should be flexible and flexible, and require good heat seeking.
In order to meet these conditions, some of the cylinder mats have been inlaid with thin steel on the side of the combustor hole and cylinder body, and there are also copper and actinide lapping.
When installing the cylinder gasket, you should pay attention to the reverse side (marking the side up). If the load is wrong, the sealing will deteriorate.
In addition, when the cylinder pad is installed, the sealant required by the factory must be daubed. Tighten the cylinder head bolts in the order of the manufacturing plant, tighten it several times, and finally use the torque to carry the hand check to achieve the specified torque.
If cylinder head bolts are not properly fixed, they will cause air leakage between adjacent cylinders and cause high pressure gas to enter cooling water to overheat the engine.
Disassembly and installation of engine valve group:
1 for the top valve type engine, remove the valve chamber cover (including crankshaft ventilation device).
2 unload the rocker arm, fix the bolt, remove the rocker shaft and rocker arm together, but be careful not to disassemble it.
3 for a GA valve type engine, when the valve is dismantled, the valve spring can be compressed by crowbar and other tools, and the lock block can be removed, and the valve and spring can be removed.
4 for the overhead camshaft type engine, the fastening screw check of the sprocket should be loosened first, the timing chain and the sprocket wheel are removed from the camshaft, and then the valve group is removed.
The assembly of the 5 valve group, in general, can be carried out in the opposite order. For example, when the camshaft top engine is used, special attention should be paid to the position of the first cylinder piston at the top dead point, so that the timing mark of the timing chain coincides with the timing mark of the sprocket.
