3.1.2.1.2. Check and adjustment of a backlash of valves

THE GENERAL DATA

The backlash of valves should be regulated only in case of detection of wrong adjustment, replacement or grinding in of valves, replacement of pushers or a camshaft.

Check

MODELS 1905 of sm³ And 1998 sm³ C 16 VALVES

Models 1905 of sm³ and 1998 sm³ with 16 valves have automatic adjustment of backlashes of valves.

OTHER MODELS

The backlash of valves is checked щупом between a cam and a pusher.

Before check of a backlash the engine at an open cowl should cool down at least 2 hours.

Example of calculation of a thickness of an adjusting plate of the valve

I – the inlet valve, E – the final valve, 1 – a measured backlash, 2 – distinction between 1 and 3,

3 – a necessary backlash, 4 – a thickness of an established plate, 5 – thickness of a new plate

Arrangement of valves

ADM – inlet valves, ECH – final valves, 1 – маслопровод greasings of bearings of a camshaft

PERFORMANCE ORDER

1. To uncover heads of the block of cylinders. 2. To draw the engine scheme on a paper. To show position of each valve together with specified клапанным a backlash. Above each valve to draw two lines for record (1) valid backlashes and (2) sizes of demanded adjustment. 3. To turn a cranked shaft before full closing of the inlet valve of the cylinder №1 (from outside a flywheel), i.e. the camshaft cam should be directed upwards. Щупом to measure a backlash between a cam and a pusher and to write down it on a line 1. 4. To repeat measurement for other seven valves, turning a cranked shaft as required so that the considered cam always has been directed upwards. 5. To calculate a difference between each measured backlash and a necessary backlash and to write down it on a line 2. 6. If the measured backlash does not correspond necessary, it is necessary to make adjustment.

Working backlash of valves (the cold engine):

 – The inlet valve: 0,20 mm;
 – The final valve: 0,40 mm;
 – The admission: ±0,05 mm.

One of methods of sequence of check of a backlash of valves

To finish to full opening the final valve of the cylinder №	To adjust a backlash of following valves
1	Inlet 3 цил., final 4 цил.
2	Inlet 4 цил., final 2 цил.
3	Inlet 2 цил., final 1 цил.
4	Inlet 1 цил., final 3 цил.

Adjustment

PERFORMANCE ORDER

1. To check up a backlash of valves according to the above described method and to write down the measured sizes of backlashes. 2. To remove driving a camshaft belt. 3. To remove маслопровод greasings of bearings of a camshaft, the distributor, a bolt of fastening of the bearing №1 and a camshaft flange. 4. To insert a steel special core in diameter of 10 mm (length 70 mm) in a pulley of a camshaft and to unscrew a bolt of fastening of this pulley. 5. To unscrew a bolt under bracket fastenings of the pipeline of a cooling liquid (a liquid from cooling system it is not necessary to merge) and to take a sheet casing. 6. One after another to unscrew nuts of fastening of covers of bearings of a camshaft. 7. To separate a cover №1 (about the distributor) from its lateral consolidation and to remove other covers (covers №2 and 4 are designated). 8. To take a camshaft on the right side. 9. To take pushers and to establish them abreast on an order (the pusher is shown by an arrow). 10. To remove adjusting plates and to measure their thickness. 11. To define a necessary thickness of adjusting plates:       – If the measured size of a backlash is too small, it is necessary to establish a plate of a smaller thickness, on the size which has been written down on a line 2;       – If the measured size of a backlash too big it is necessary to establish a plate большей thickness, on the size which has been written down on a line 2. 12. To spend in drawing three more lines below each valve. 13. On lines (4) to put the measured thickness of plates which have been removed from the engine, then to add or subtract a difference with a line (2), to receive a necessary thickness of plates, and to write down on a line (5). The prevention After replacement of one of system details timing or after grinding in of valves it is necessary to establish 8 adjusting plates in the thickness, at least, 2,15 mm. 14. To establish pushers with plates of a necessary thickness. 15. To establish a camshaft and covers of bearings. It is necessary to observe an installation order. To tighten covers of bearings the moment of 15 Nanometers. 16. To turn a camshaft by means of a bolt of a pulley and to check up a backlash of valves. In case of detection of a wrong backlash adjustment is necessary for repeating. 17. To check up, whether there is a cranked shaft in position of installation of system timing. 18. To replace lateral consolidation of a cover of the bearing №1, to grease герметизирующей with paste two surfaces of consolidation and the bottom connection. 19. To establish a flange of fastening of a camshaft. 20. To establish new consolidation of a camshaft from outside a drive (the adaptation 7.0153 Е together with a bolt and a pulley lining). 21. To establish a sheet casing without a tightening of fixing elements. 22. To centre a casing by means of a core in diameter of 10 mm. 23. To establish a pulley of a camshaft and to insert into a corresponding place a core of installation of system timing. 24. To tighten a bolt of fastening of a pulley the moment of 80 Nanometers. 25. To screw in bolts of fastening of a casing. 26. To establish the channel of greasing of bearings of a camshaft, the distributor, a cover of a head of the block of cylinders and to connect wires. 27. To establish driving a camshaft belt. 28. To adjust a corner of an advancing of ignition.