Installing the cylinder head and valve mechanism D-245
If it is necessary to replace the valve seats, use the set of special mandrels shown in fig. 1.
The installation of valve springs and valve cups is recommended to be done using a special tool and a mandrel shown in Figure 2 and 3.
Cylinder head gaskets must be lubricated on both sides with a graphite paste consisting of 60% engine oil and 40% graphite (by weight).
PTFE rings must be put on the metal edging of the holes for the sleeves.
The tightening of the bolts (nuts) for fastening the head must be carried out in the sequence indicated in fig. 4. Tightening torque - 190 ... 210 Nm.
Push rods should be installed in the holes of the cylinder heads so that the tips of the rods fit into the recesses of the pushers.
When installing the valve mechanism, the spheres of the adjusting screws must be aligned with the tips of the rods.
Stud nuts and valve train bolts must be fully tightened.
The gap between the rocker striker and the end of the valve stem on an unheated diesel should be:
- - inlet valves - 0.2 +0.05 mm;
- - exhaust valves - 0.45-0.05 mm.
Adjustment should be done in the following sequence:
- turn the crankshaft until the valves in the first cylinder overlap (the inlet valve of the first cylinder starts to open, and the exhaust valve closes) and adjust the gaps in the fourth, sixth, seventh and eighth valves (counting from the fan).
Then rotate the crankshaft one turn, setting the overlap in the fourth cylinder, and adjust the clearances in the first, second, third and fifth valves.
To adjust the gap, loosen the locknut of the screw on the adjustable valve rocker (Fig. 5) and, turning the screw, set the required gap on the feeler gauge between the rocker striker and the end of the valve stem.
After setting the gap, tighten the locknut.
After adjusting the valve clearance, install the cylinder head cover cap.
Assembly parts of the diesel head D-245.12 (Fig. 6).
Checking the tightening of the cylinder head bolts must be done after running in and every 40 thousand km. km of run on a warm diesel engine.
Check and, if necessary, adjust the gaps between the valves and rocker arms every 20 thousand kilometers, as well as after removing the cylinder head, tightening the cylinder head bolts and when valves knock.
Valve clearances should be checked at temperatures not exceeding 60°C.