Warm engine:
- 0.20-0.30 for inlet valve
- 0.40-0.50mm for exhaust valve
Cold engine:
- 0.15-0.25mm for inlet valve
- 0.35-0.40mm for exhaust valve
As a rule, this clearance is set on a cold engine. After a run of 1000 km, the clearance must be checked and, if necessary, adjusted.
The location of the valves is shown in fig. 220. If the gap is more or less than the allowable one, then it is necessary to determine the amount of adjustment and adjust as follows:
Remove the valve cover.
Set the piston of the 1st cylinder to TDC. Both cams will then take the position shown in fig. 221. Use the pulley bolts to turn the crankshaft. The camshaft pulley must not be rotated, as this will stretch the toothed belt shaft.
Measure clearance for both valves (first - graduation) and write down the result.
Turn the shaft three times by half a turn, after the first turn, measure the valve clearances of the third cylinder, then - the fourth cylinder, after the fourth - the second cylinder. Record the measurement results.
Compare the obtained values with the recommended ones.
Determine which valves require adjustment. Remove the shim from the valve lifter that needs adjustment. To do this, turn the camshaft so that the cams are directed in the opposite direction from the pusher. Rotate the pushers so that they are in the position shown in fig. 222.
To replace the shim, tool 2078 or equivalent must be used. The way to use it is as follows:
- Insert the tool under the camshaft and push down on the pusher with it (pic. 223).
- Using pliers 10-208, inserted into both grooves of the pusher, grasp the shim and remove it.
If you do not have the above tool, then removing the shim will be difficult.
On the lower end of the removed washer, its thickness is indicated; compare it with the measured clearance.
Choose an adjusting washer of the required thickness. The thickness of the washer must be checked with a micrometer. Insert a new washer onto the tappet with the thickness designation facing down.
Washers are produced with a thickness of 3.00-4.25 mm. Used washers can be reused if they are not damaged or worn. Below in table. 13 is an example of how the washer thickness can be determined.
Table 13
Size | Exhaust valve | Inlet valve |
Recommended Size | 0.4-0.5mm | 0.2-0.3mm |
Measurement result | 0.35 mm | 0.35 mm |
gap size | +0.05 mm | -0.05mm |
Sometimes it is not possible to set the gap using even the thinnest washer. This situation can occur after milling the valve seat, when the head height is still within the allowable dimensions.
For this case, valves shortened by 0.5 mm are produced.
Below in table. 14 shows data on the range of used shims.
Table 14. Shims and Order Numbers
Thickness, mm | Order number | Thickness, mm | Order number |
3,00 | 056109555 | 3,65 | 056109568 |
3,05 | 056109556 | 3,70 | 056109569 |
3,10 | 056109557 | 3,75 | 056109570 |
3,15 | 056109558 | 3,80 | 056109571 |
3,20 | 056109559 | 3,85 | 056109572 |
3,25 | 056109560 | 3,90 | 056109573 |
3,30 | 056109561 | 3,95 | 056109574 |
3,35 | 056109562 | 4,00 | 056109575 |
3,40 | 056109563 | 4,05 | 056109576 |
3,45 | 056109564 | 4,10 | 056109577 |
3,50 | 056109565 | 4,15 | 056109578 |
3,55 | 056109566 | 4,20 | 056109579 |
3,60 | 056109567 | 4,25 | 056109580 |
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