Cylinder head
1. Check the flatness of the surface of the cylinder head connector with the cylinder block and manifolds. To do this, you must use a special ruler and a set of probes. Placing the ruler in the planes indicated in the figure, measure the non-flatness of the connector surface with probes.
Note:
Flatness of cylinder head gasket surface:
- less than 0.03mm for width,
- less than 0.09mm for length,
- less than 0.012 mm / 50x50 mm.
The flatness of the mating surface of the collector:
- less than 0.025mm for width,
- less than 0.160mm for length.
2. Check the combustion chambers, inlet and outlet passages and the surface of the connector with the cylinder block for damage. If any defects are found, replace the cylinder head assembly.
Valves, tappets, guide bushings and valve springs
1. Check the technical condition of the guide bushings and valves.
Using a bore gauge, measure the inside diameter of the valve guide as shown.
Note:
Standard value of inner diameter:
- Intake: 5.975 - 6.000 mm.
- Exhaust: 5.975 - 6.000 mm.
Using a micrometer, measure the outside diameter of the valve stem as shown in the illustration.
Note:
The standard value of the outer diameter of the valve:
- Intake: 5.933 - 5.953 mm.
- Exhaust: 5.905 - 5.925 mm.
The difference between the inner diameter of the guide sleeve and the outer diameter of the valve stem is the clearance between the valve and the sleeve. If the gap is greater than the maximum allowable value, it is necessary to replace the valve assembly with the sleeve.
Note:
Standard value:
- Inlet: 0.022 - 0.067 mm.
- Outlet: 0.050 - 0.095 mm.
2. Check the technical condition of the valves:
Check the angle of sharpening of the working chamfer of the valve head.
Check the valve surface for excessive wear. If any defects are found, replace the valve with a new one.
Check the thickness of the valve head band. If the thickness of the valve head band is less than the maximum allowable, it is necessary to replace the valve with a new one.
Note: The standard size of the belt bar:
- Inlet: 1.25 mm.
- Graduation: 1.25mm.
Measure the overall length of the valve.
Note:
Standard valve length:
- Intake: 108.3 mm.
- Graduation: 108.2 mm.
3. Check the technical condition of the valve seats:
Make sure that the valve fits snugly against the seat around its entire circumference. Replace valve seats if necessary.
Before restoring the valve seats, it is necessary to check the technical condition of the valve guides. If any defects are found, it is necessary to replace the sleeve, and then carry out the restoration of the seat. The thickness of the contact surface of the seat with the valve must correspond to the standard value.
4. Check the technical condition of the valve springs:
Using a steel square, measure the amount of deflection from the vertical axis of the spring.
Note: Permissible deviation from the vertical axis: 1.571.15 mm.
Using a caliper, measure the free length of the spring. If the free length of the spring does not correspond to the standard value, it is necessary to replace the spring with a new one.
Note:
Standard spring length: 44.0 mm.
Loaded length:
- 19.9±1.0kg/36.6mm.
- 44.1±2.2kg/27.6mm.
Camshaft
1. Using a micrometer, measure the height of the camshaft cams. If the height of the camshaft cam is less than the maximum allowable, the camshaft assembly must be replaced.
Note: Standard jaw height:
- Inlet: 40.094 mm.
- Exhaust: 40.425 mm.
2. Check up a backlash in bearings of a camshaft.
Clean and wash the bearing caps and camshaft journals.
Install the camshafts in the cylinder head.
Lay special plastic gauges on the camshaft journals, as shown in the figure.
Install the camshaft bearing caps and tighten the bolts to the recommended torque.
Note: Tightening torque: 10.0-12.7 Nm.
Attention. Do not turn the camshaft.
Remove the camshaft bearing caps.
Measure the thickness of the plastic gauge (a scale is attached to the plastic gauge set). Determine the amount of clearance in the bearings.
Note: Standard bushing gap: 0.040 - 0.074 mm.
Note: If the bearing clearance exceeds the allowable limit, the camshaft must be replaced. If necessary, replace bearing caps or cylinder head assembly.
Remove all plastic gauges.
Remove camshafts.
3. Measure the axial clearance of the camshaft.
Install the camshafts.
Using a dial gauge, measure the end play while moving the camshaft forward/rear.
Note: The standard value of the axial clearance of the camshaft is 0.05-0.15 mm.
If the axial clearance exceeds the maximum allowable value, the camshaft must be replaced. If necessary, replace the camshaft bearing caps and cylinder head assembly.
Remove camshafts.
Hydraulic lifters
Hold the hydraulic compensator filled with engine oil by part A and press part B. If part B moves, replace the hydraulic compensator with a new one.