Structural principle of main body cylinder head machine of Volvo excavator engine and introduction of disassembly and maintenance
VOLVO 88890300 Vocom Interface for VOLVO/Renault/UD/Mack Truck Diagnose
(1) Description of the cylinder head
The cylinder head of the D6D engine is made of gray cast iron and is designed as a block head. Combustion air enters vertically and exits with exhaust side covers. The intake and outlet ports are located on one side of the cylinder head.
(2) Valve
Each cylinder of the engine has an intake valve and an exhaust valve. The valve guides are retracted into the cylinder head. The valve seat inserts are made of high-quality steel and are also shrunk into the cylinder head. The valve is turned eccentrically by means of a rocker arm. The new compression cone connection allows easy turning of the valve even under heavy loads. Note that there is a special installation instruction for the D6D valve spring.
The color code on the spring must face the bottom.
The rocker arm lubrication is integrated with the lube oil circuit. Oil supply can be via tappets and push rods. Table 2-1 shows the angle of the valve seat.
(3) Valve clearance adjustment
Valve clearances must be checked and adjusted at specified intervals. During operation, the engine oil temperature must be between 20°C and 80°C. Table 2-2 shows valve clearance values.
The adjustment steps are as follows. ① Remove the rocker cover.
②Turn the crankshaft until the two valves in cylinder 1 overlap (the exhaust valve is about to close and the intake valve is about to open).
③ Adjust the clearance of the valve marked black in Figure 2-4. Mark the corresponding rocker arm with chalk to indicate adjustment.
④ Tighten the lock nut to 20N·m (15lbf·ft), and check the adjustment again with a feeler gauge, as shown in Figure 2-5.
⑤Turn the crankshaft one full turn (360°). Now adjust the clearance of the valve marked black in the diagram.
⑥ Install the valve cover with a new gasket, and then tighten the screws, as shown in Figure 2-6.
This measurement is made on each piston. The maximum measured projection will determine the cylinder head gasket thickness (see Table 2-3). Gaskets are available in 3 different thicknesses, identified by hole 4.
1 hole=1.2mm
2 holes = 1.3mm 3 holes = 1.4mm (5) install the cylinder head
① Before installing the cylinder head to the crankcase, the sealing surface of the cylinder head gasket must be clean and free from oil. Note the pin sleeve.
②Apply a thin layer of oil to the cylinder head bolts.
③ It is necessary to follow the tightening sequence in the diagram next to it.
The tightening sequence is shown in Figure 2-8.
Step 1: 30N.m Step 2: 80N.m Step 3: 90°
