2.1.5. Gas distribution mechanism

The drive of verkhneraspolozhenny (SOHC and DOHC) camshafts is carried out single-row  (engines M 102, M 123) or  a two-row (engines M 110 and M 115) chain.

Tension of a chain is regulated by the hydraulic tension device with blocking.

Camshaft drive cover from aluminum alloy.


Gas distribution phases

Calculation of phases of gas distribution is given at a zero settlement gap of valves and height of raising of the valve of 2 mm.

Size after the run of 20000 km is specified in brackets.

Parameter, mm

Engine model
M 115.938
M 102.920, M 102.939
M 102.980, M 102.982
M 115.954

The beginning of opening of the inlet valve to admission step VMT with an advancing

14,0

11,0 (12,0)

11,0 (12,0)

14,0

Closing of the inlet valve after compression step NMT with delay

20,0

17,0 (18,0)

17,0 (18,0)

27,0

The beginning of opening of the final valve to NMT of the working course with an advancing

22,0

32,0 (31,0)

32,0 (31,0)

36,5

Closing of the final valve after release step VMT with delay

12,0

13,0 (12,0)

13,0 (12,0)

18,50

Marking of the camshaft

5

12

23

13

Parameter, mm
M 123.920, M 123.921
M 110.923
M 110.984, M 110.988

The beginning of opening of the inlet valve to admission step VMT with an advancing

15,0

7,0

7,0

Closing of the inlet valve after compression step NMT with delay

21,0

21,0

21,0

The beginning of opening of the final valve to NMT of the working course with an advancing

21,0

30,0

30,0

Closing of the final valve after release step VMT with delay

11,0

12,0

12,0

Marking of the camshaft

02

right: 57
left: 25

71
67


Camshafts

To five -  (engines M 102 and M 115) or seven-basic  (engines M 110 and M 123) the hollow camshaft. The forward end of a shaft is closed by a bolt of fastening of an asterisk, and back — a steel cap. Oil comes to the canal of a shaft through a flute and an opening of a back support and provides lubricant of a basic shaft. At an end face of a flange of fastening of an asterisk on a shaft the digital tag is beaten out.


Characteristics of camshafts

The pulling of a distributive chain can be compensated by movement of an asterisk of the camshaft.

Characteristic

Value

Admissible radial beating of necks of the camshaft, mm

0,025 — 0,030

Purity of a surface of a support of the bearing of the camshaft, micron

0,003


Shift of an asterisk of the camshaft, mm

Amendment

0,7

6 °

0,9

8 °

1,1

9,5 °

1,3

11,5 °

Gaps in the mechanism of the drive of valves on the cold and hot engine for inlet and final valves are given in the table. On engines with hydraulic compensation of a gap in the drive of valves gaps of valves are not regulated.

Support of bearings not of a termoobrabotana. the 1st support of the engine M 110 not a shlifovana, on it is established the plug.

Parameter, mm

Engine model
M 115.938
M 102.920, M 102.939
M 102.980, M 102.982
M 115.954

On the cold engine

  • for inlet valves

0,10

0,15

0,15

0,10

  • for final valves

0,20

0,20

0,20

0,20

On the heated-up engine (t ° oils 45 — 75 °C)

  • for inlet valves

0,15

0,30

0,30

0,15

Parameter, mm
M 123.920, M 123.921
M 110.923
M 110.984, M 110.988

On the cold engine

  • for inlet valves

0,10

0,10

0,10

 
  • for final valves

0,20

0,25

0,25

 

On the heated-up engine (t ° oils 45 — 75 °C)

  • for inlet valves

0,15

0,15

0,15

 


Characteristics of camshafts

Parameter, mm

Engine model
M 115.938
M 102.920, M 102.939
M 102.980, M 102.982
M 115.954
Support 1

Diameter of a neck of a shaft

  • nominal

34,959 — 34,975

31,934 — 31,950

34,959 — 34,975

  • 1st repair size

34,859 — 34,875

*

34,859 — 34,875

  • 2nd repair size

34,709 — 34,725

32,434 — 32,450

34,709 — 34,725

Diameter of an opening of a support

  • nominal

35,000 — 35,016

32,000 — 32,025

35,000 — 35,016

  • 1st repair size

34,900 — 34,916

*

34,900 — 34,916

  • 2nd repair size

34,750 — 34,766

32,500 — 32,525

34,750 — 34,766

Support 2 and 3

Diameter of a neck of a shaft

  • nominal

48,959 — 48,975

48,959 — 48,975

  • 1st repair size

48,859 — 48,875

48,859 — 48,875

  • 2nd repair size

48,709 — 48,725

48,709 — 48,725

Diameter of an opening of a support

  • nominal

49,000 — 49,016

49,000 — 49,016

  • 1st repair size

48,900 — 48,916

48,900 — 48,916

  • 2nd repair size

48,750 — 48,766

48,750 — 48,766

Support 4

Diameter of a neck of a shaft

  • nominal

  • 1st repair size

  • 2nd repair size

Diameter of an opening of a support

  • nominal

  • 1st repair size

  • 2nd repair size

Support 5

Diameter of a neck of a shaft

  • nominal

  • 1st repair size

  • 2nd repair size

Diameter of an opening of a support

  • nominal

  • 1st repair size

  • 2nd repair size

Support 6

Diameter of a neck of a shaft

  • nominal

  • 1st repair size

  • 2nd repair size

Diameter of an opening of a support

  • nominal

  • 1st repair size

  • 2nd repair size

Support 7

Diameter of a neck of a shaft

  • nominal

  • 1st repair size

  • 2nd repair size

Diameter of an opening of a support

  • nominal

  • 1st repair size

  • 2nd repair size

Parameter, mm
M 123.920, M 123.921
M 110.923
M 110.984, M 110.988
 
Support 1

Diameter of a neck of a shaft

  • nominal

34,93 — 34,95

23,98 — 23,99

 
  • 1st repair size

34,83 — 34,85

*

 
  • 2nd repair size

34,68 — 34,70

*

 

Diameter of an opening of a support

  • nominal

35,00 — 35,02

38,00 — 38,02 *

 
  • 1st repair size

34,90 — 34,92

*

 
  • 2nd repair size

34,75 — 34,77

*

 
Support 2 and 3

Diameter of a neck of a shaft

  • nominal

48,93 — 48,95

49,93 — 49,94

 
  • 1st repair size

48,83 — 48,85

49,68 — 49,70

 
  • 2nd repair size

48,68 — 48,70

49,43 — 49,45

 

Diameter of an opening of a support

  • nominal

49,00 — 49,02

50,05 — 50,07

 
  • 1st repair size

48,90 — 48,92

49,80 — 49,82

 
  • 2nd repair size

48,75 — 48,77

49,55 — 49,57

 
Support 4

Diameter of a neck of a shaft

  • nominal

49,93 — 49,95

49,93 — 49,95

 
  • 1st repair size

49,83 — 49,85

49,68 — 49,70

 
  • 2nd repair size

49,69 — 49,70

49,43 — 49,45

 

Diameter of an opening of a support

  • nominal

50,00 — 50,02

50,00 — 50,02

 
  • 1st repair size

49,90 — 49,92

49,75 — 49,77

 
  • 2nd repair size

49,75 — 49,77

49,50 — 49,52

 
Support 5

Diameter of a neck of a shaft

  • nominal

51,42 — 51,44

 
  • 1st repair size

51,17 — 51,19

 
  • 2nd repair size

50,92 — 50,94

 

Diameter of an opening of a support

  • nominal

51,50 — 51,52

 
  • 1st repair size

51,25 — 51,27

 
  • 2nd repair size

51,00 — 51,02

 
Support 6

Diameter of a neck of a shaft

  • nominal

52,92 — 52,94

 
  • 1st repair size

52,67 — 52,69

 
  • 2nd repair size

52,47 — 52,49

 

Diameter of an opening of a support

  • nominal

53,00 — 53,02

 
  • 1st repair size

52,75 — 52,77

 
  • 2nd repair size

52,50 — 52,52

 
Support 7

Diameter of a neck of a shaft

  • nominal

53,92 — 53,94

 
  • 1st repair size

53,67 — 53,69

 
  • 2nd repair size

53,43 — 53,45

 

Diameter of an opening of a support

  • nominal

54,00 — 54,02

 
  • 1st repair size

53,75 — 53,77

 
  • 2nd repair size

53,50 — 53,52

 

* The plug of the 1st support has the outer diameter of 37,93 — 37,95 mm and internal diameter of 24,00 — 24,01 mm.


Hydraulic tension device

The pusher piston under the influence of oil pressure in lubricant system of the engine and an internal spring constantly influences a boot of a natyazhitel.

Characteristic

Value

Diameter of an opening of supply of oil, mm

1,1

Diameter of a maslovypuskny opening, mm

1,2