2. Remove the valves from the cylinder head.
3. Before testing, clean all parts to be tested with a cleaning agent and dry with compressed air.
4. Make sure that the parts are not scratched or have any signs of impact or abnormal wear. If any defects are found, replace the parts with new ones.
5. Make sure that the valves move freely in the guide bushings.
6. Using a micrometer, measure the valve head diameter (D) and valve length (L).
7. Using a micrometer, measure the diameter of the valve stem (d1) at a distance (X1) equal to 41 mm for the inlet valve or 31 mm for the outlet valve.
8. Check the clearance between the valve stem and the valve guide:
Note:
The clearance between the valve stem and the guide bushing can be measured in two ways.
The clearance between the valve stem and the guide bushing should be:
- for inlet valve: 0.02 -0.05 mm;
- for exhaust valve: 0.03~0.06mm.
Measuring the clearance between the valve stem and the guide bushing using a dial indicator
- Install the clamping plate to measure the cylinder liner protrusion (Mot. 252-01) on the cylinder head.
- Remove the valve by 25 mm.
- Install a dial indicator with a support.
- Place the dial indicator feeler gauge against the valve head at right angles to the valve stem.
- Push the valve head towards the dial indicator.
- Reset the hour indicator.
- Push the valve head in the direction opposite to the dial indicator.
- Record the value displayed on the dial indicator.
- Calculate the actual valve stem to guide clearance by dividing the dial indicator reading in half.
Measuring the clearance between the valve stem and the guide bushing using a micrometer and bore gauge
- Using a bore gauge, measure the inner diameter (2) of the valve guide bushing.
(This article is taken from the website: «RenaultBook.ru»)
- Use a micrometer to measure the diameter of the valve stem (3).
- Calculate the actual clearance value by subtracting the valve stem diameter (2) from the inner diameter of the guide bushing (1) and dividing in half.
9. Check the valve seat depth:
Note: This check is performed when replacing a valve. It is necessary to ensure that the position of the valve head relative to the contact surface of the cylinder head is within the allowable range to ensure normal engine operation. If the position of the valve head is not within the normal range, the engine may be damaged.
- Install the dial indicator (5) with the dial indicator support (Mot. 251-01) (4) on the cylinder head, placing them on the pressure plate to measure the cylinder liner protrusion (Mot. 252-01) (3).
- Place the dial indicator probe on the contact surface of the cylinder head.
- Reset the hour indicator.
- Measure and record the seat depth values of each valve in the seats.
Note: The valve seating depth should be +0.07 mm (performance) up to -0.07 mm (deepening) for intake and exhaust valves.
- Remove the dial indicator with supports from the cylinder head.