2.1.4. Krivoshipno-shatunny mechanism
Pistons
The piston from aluminum alloy with the flat bottom.
The tag of diameter of the piston and the shooter for orientation of the piston at its installation in the cylinder which has to be directed towards the camshaft drive are specified the bottom of the piston. On weight pistons of one engine should not differ from each other more than on 4,9 g.
Characteristic |
Value |
Gap between the piston and the cylinder, mm |
|
nominal |
|
|
0,016 — 0,040 |
|
0,025 — 0,035 |
maximum permissible in operation |
0,10 |
Diameter of pistons *
Parameter, mm |
Engine model
|
|||
M 115.938
|
M 102.920, M 102.939
|
M 102.980, M 102.982
|
M 115.954
|
|
nominal |
||||
|
86,98 |
88,968 — 88,982 |
95,468 — 95,482 |
93,73 |
|
— |
88,978 — 88,992 |
95,478 — 95,492 |
— |
|
— |
88,988 — 89,002 |
95,488 — 95,502 |
|
1st repair size |
||||
|
87,48 |
89,468 — 89,482 |
95,968 — 95,982 |
94,13 |
|
— |
89,478 — 89,492 |
95,978 — 95,992 |
— |
|
— |
89,488 — 89,502 |
96,988 — 96,002 |
— |
2nd repair size |
||||
|
87,98 |
89,968 — 89,982 |
96,468 — 96,482 |
94,53 |
|
— |
89,978 — 89,992 |
96,478 — 96,492 |
— |
|
— |
89,988 — 90,002 |
96,488 — 96,502 |
— |
3rd repair size |
||||
|
88,48 |
— |
— |
— |
Parameter, mm
|
M 123.920, M 123.921
|
M 110.923
|
M 110.984, M 110.988
|
|
nominal |
||||
|
85,98 |
85,98 |
|
|
|
— |
— |
|
|
|
— |
— |
|
|
1st repair size |
||||
|
86,48 |
86,48 |
|
|
|
— |
— |
|
|
|
— |
— |
|
|
2nd repair size |
||||
|
86,98 |
86,98 |
|
|
|
— |
— |
|
|
|
— |
— |
|
|
3rd repair size |
||||
|
— |
— |
|
* The difference of sizes is caused model year of release.
Piston fingers
Piston finger steel, polished, floating. From axial shift the finger is kept by lock rings.
Characteristics of piston fingers
Parameter, mm |
Engine model
|
|
M 102.920, M 102.939
|
M 102.980, M 102.982
|
|
Diameter |
||
|
23,995 — 24,000 |
|
|
15,5 |
|
Length |
— |
|
Gap between a finger and the plug of the top head of a rod |
0,007 — 0,02 |
|
Gap between a finger and a lug of the piston |
0,002 — 0,012 |
Piston rings
On the external surface of the piston three flutes for installation of rings are pierced. Situation at assembly: the tag of "Torahs" has to be directed up. On engines M 102 piston rings of Goyotze or TRW can be established.
Features of a design of piston rings of Goyotze
The top compression ring cylindrical, with a facet on an internal surface, with porous chromium plating of an external surface. The lower compression ring conical, with a fillet. An oil scraper ring with two facets, a razzhimny twisted spring and the chromeplated external surface.
Features of a design of piston rings of TRW
The top compression ring cylindrical, with a facet on an internal surface, with the chromeplated polished barrel-shaped external surface. The lower compression ring conical, with a fillet and the barrel-shaped chromeplated external surface. An oil scraper ring with two facets, with a razzhimny twisted spring and the chromeplated external surface.
Characteristic of piston rings
Parameter, mm |
Engine model
|
|||
M 115.938
|
M 102.920, M 102.939
|
M 102.980, M 102.982
|
M 115.954
|
|
Gap on height | ||||
top compression ring |
0,05 — 0,08 |
0,05 — 0,085 |
0,050 — 0,085 |
|
lower compression ring |
0,03 — 0,06 |
0,01 — 0,03 |
0,03 — 0,06 |
|
oil scraper ring |
0,01 — 0,04 |
0,01 — 0,045 |
0,01 — 0,04 |
|
Limit gap on height in operation | ||||
top compression ring |
0,15 |
|||
lower compression ring |
0,10 |
|||
oil scraper ring |
0,16 |
0,10 |
0,16 |
|
Gap in the lock | ||||
top compression ring |
0,30 — 0,55 |
|||
lower compression ring |
0,25 — 0,45 |
|||
oil scraper ring |
0,25 — 0,50 |
|||
Limit gap in the lock in operation | ||||
top compression ring |
1,0 |
1,0 |
1,0 |
|
lower compression ring |
0,8 |
0,8 |
0,8 |
|
oil scraper ring |
0,8 |
0,8 |
0,8 |
|
Parameter, mm
|
M 123.920, M 123.921
|
M 110.923
|
M 110.984, M 110.988
|
|
Gap on height | ||||
top compression ring |
0,050 — 0,085 |
|||
lower compression ring |
0,03 — 0,06 |
|||
oil scraper ring |
0,01 — 0,04 |
|||
Limit gap on height in operation | ||||
top compression ring |
0,15 |
|||
lower compression ring |
0,10 |
|||
oil scraper ring |
0,16 |
|||
Gap in the lock | ||||
top compression ring |
0,30 — 0,55 |
|||
lower compression ring |
0,25 — 0,45 |
|||
oil scraper ring |
0,25 — 0,50 |
|||
Limit gap in the lock in operation | ||||
top compression ring |
1,0 |
|||
lower compression ring |
0,8 |
|||
oil scraper ring |
0,8 |
Rods
Double-T section rod steel, shod with replaceable inserts. Cover of the lower head of a rod of direct section. For an oil supply to the rubbing surfaces in a core of a rod the opening is drilled. On weight rods of one engine should not differ from each other more than on 5 g.
Characteristic |
Value |
Not parallelism and not planeness of openings of heads at measurement at distance of axes of 100 mm from a rod core, no more, than a mm |
|
|
0,045 |
|
0,030 |
|
0,040 |
|
0,040 |
Roughness of a surface of connection of the piston with a rod, micron |
0,002 |
Beating of openings of the lower head of a rod, no more, than a mm |
0,02 |
Characteristics of rods
Parameter, mm |
Engine model
|
|||
M 115.938
|
M 102.920, M 102.939
|
M 102.980, M 102.982
|
M 115.954
|
|
Diameter of the lower head of a rod |
55,60 — 55,62 |
51,60 — 51,619 |
55,60 — 55,62 |
|
Diameter of the top head of a rod |
29,00 — 29,02 |
27,00 — 27,021 |
29,00 — 29,02 |
|
Internal diameter of the plug of the top head |
26,012 — 26,018 |
24,007 — 24,015 |
26,012 — 26,018 |
|
Distance between axes an opening of heads |
148,95 — 149,05 |
144,95 — 145,05 |
148,95 — 149,05 |
|
Width of the lower head |
32.08 — 32,10 |
27,857 — 27,90 |
32.08 — 32.10 |
|
Parameter, mm
|
M 123.920, M 123.921
|
M 110.923
|
M 110.984, M 110.988
|
|
Diameter of the lower head of a rod |
51,60 — 51,62 |
|||
Diameter of the top head of a rod |
26,00 — 26,02 |
|||
Internal diameter of the plug of the top head |
23,007 — 23,013 |
|||
Distance between axes an opening of heads |
130,95 — 131,05 |
|||
Width of the lower head |
27,86 — 27,89 |
Rod cover bolts
Bolts with the extended core.
Characteristic |
Value |
Diameter of a carving |
M9x1 |
Diameter of a core, mm |
|
M 102 |
|
|
8,3 — 8,4 |
|
8,0 |
M 115 |
|
|
8,3 — 8,4 |
|
8,0 |
M 110 |
|
|
7,3 — 7,4 |
|
7,1 |
M 123 |
|
|
7,3 — 7,4 |
|
7,1 |
Bolt head height (M 102), mm |
5,0 — 5,2 |
Length of a carving part (M 102), mm |
40,0 |
Length to a head (M 102), mm |
51,7 — 52,0 |
Bent shaft
Bent shaft steel, shod four - (engine M 123), five - (engines M 102, M 115) or seven-basic (engine M 110).
The bent shaft of 4-cylinder engines (M 102, M 115) has eight counterbalances, 6-cylinder (M 110, M 123) — 12 counterbalances.
Characteristic |
Value |
Admissible face beating of cheeks of the radical bearing, mm |
0,02 |
Radiuses of galitel of radical and conrod necks, mm |
2,5 — 3,0 |
Diameter of the forward end of a bent shaft, mm |
29,987 — 30,000 |
Admissible beating of the forward end of a bent shaft, mm |
0,030 |
Diameter of a basic surface of a back epiploon, mm |
92,874 — 92,928 |
Non-cylindricity of a flange, to, mm |
0,02 |
Flange beating, to, mm |
0,012 |
Beating of radical necks (the bent shaft is established on prisms of necks 1 and 5), to, mm |
|
|
0,07 |
|
0.10 |
Gaps of a bent shaft of the engine M 102
Characteristic |
Value |
Diametrical gap between a radical neck and inserts, mm |
|
|
0,025 — 0,045 |
|
0,070 |
Diametrical gap between a conrod neck and inserts, mm |
|
|
0,030 — 0,050 |
|
0,070 |
Axial gap of a bent shaft, mm |
|
|
0,06 — 0,22 |
|
0,30 |
Axial gap between a rod and a bent shaft, mm |
|
|
0,11 — 0,23 |
|
0,50 |
Admissible ovality of radical and conrod necks in operation, mm |
0,025 |
Admissible conicity in operation, mm |
|
|
0,010 |
|
0,015 |
Admissible imbalance of a bent shaft in operation, cm |
15 |
Parameters of bent shafts
Parameter, mm |
Engine model
|
|||
M 115.938
|
M 102.920, M 102.939
|
M 102.980, M 102.982
|
M 115.954
|
|
Diameter of radical necks | ||||
nominal |
||||
|
69,95 — 69,96 |
57,935 — 57,940 |
69,95 — 69,96 |
|
|
* |
57,940 — 57,945 |
* |
|
|
* |
57,945 — 57,950 |
* |
|
|
* |
57,950 — 57,955 |
* |
|
|
* |
57,955 — 57,960 |
* |
|
|
* |
57,960 — 57,965 |
* |
|
1st repair size |
69,70 — 69,71 |
57,705 — 57,715 |
69,70 — 69,71 |
|
2nd repair size |
69,45 — 69,46 |
57,455 — 57,465 |
69,45 — 69,46 |
|
3rd repair size |
69,20 — 69,21 |
57,205 — 57,215 |
69,20 — 69,21 |
|
4th repair size |
68,95 — 68,96 |
57,955 — 57,965 |
68,95 — 68,96 |
|
Width of radical necks | ||||
nominal |
34,00 — 34,03 |
28,500 — 28,521 or 28,600 — 28,621 |
34,00 — 34,03 |
|
1st repair size |
34,00 — 34,03 |
28,700 — 28,721 |
34,00 — 34,03 |
|
2nd repair size |
to 34,60 |
28,900 — 28,921 |
to 34,60 |
|
3rd repair size |
to 34,60 |
29,000 — 29,021 |
to 34,60 |
|
4th repair size |
to 34,60 |
* |
to 34,60 |
|
Distance between basic surfaces of persistent half rings | ||||
|
— |
23,979 — 24,000 |
— |
|
Diameter of conrod necks | ||||
nominal |
51,97 — 51,96 |
47,955 — 47,965 |
51,97 — 51,96 |
|
1st repair size |
51,70 — 51,71 |
47,705 — 47,715 |
51,70 — 51,71 |
|
2nd repair size |
51,45 — 51,46 |
47,455 — 47,465 |
51,45 — 51,46 |
|
3rd repair size |
51,20 — 51,21 |
47,205 — 47,215 |
51,20 — 51,21 |
|
4th repair size |
50,95 — 50,96 |
46,955 — 46,965 |
50,95 — 50,96 |
|
Width of conrod necks | ||||
nominal |
32,0 — 32,1 |
27,000 — 28,034 |
32,0 — 32,1 |
|
repair size |
to 32,30 |
to 28,30 |
to 32,30 |
|
Parameter, mm
|
M 123.920, M 123.921
|
M 110.923
|
M 110.984, M 110.988
|
|
Diameter of radical necks | ||||
nominal |
||||
|
59,95 — 59,96 |
|||
|
* |
|||
|
* |
|||
|
* |
|||
|
* |
|||
|
* |
|||
1st repair size |
59,70 — 59,71 |
|||
2nd repair size |
59,45 — 59,46 |
|||
3rd repair size |
59,20 — 59,21 |
|||
4th repair size |
58,95 — 58,96 |
|||
Width of radical necks | ||||
nominal |
29,00 — 29,02 |
|||
1st repair size |
29,00 — 29,02 |
|||
2nd repair size |
to 29,60 |
|||
3rd repair size |
to 29,60 |
|||
4th repair size |
to 29,60 |
|||
Distance between basic surfaces of persistent half rings | ||||
— |
— |
— |
||
Diameter of conrod necks | ||||
nominal |
47,95 — 47,96 |
|||
1st repair size |
47,70 — 47,71 |
|||
2nd repair size |
47,45 — 47,46 |
|||
3rd repair size |
47,20 — 47,21 |
|||
4th repair size |
46,95 — 46,96 |
|||
Width of conrod necks | ||||
nominal |
28,00 — 28,08 |
|||
repair size |
to 28,30 |
Inserts of radical and conrod bearings
Color of marking of inserts of bearings: blue or gray.
Characteristic |
Value |
Width of inserts, mm |
|
Engines M 102 and M 115 |
|
|
33,80 — 33,90 |
|
34,40 — 34,60 |
Engines M 110 and M 123 |
|
|
28,78 — 28,90 |
|
29,40 — 29,60 |
Inserts for all steps of repair are delivered with excess on width and have to be finished by the size of the repolished bearing.
|
Engines of models M 102 releases since July, 1986 have thickness of inserts of radical bearings increased by 0,003 mm for reduction of a gap and noise reduction during the operation of the engine. |
Characteristics of inserts of radical and conrod bearings
Parameter, mm |
Engine model
|
|||
M 115.938
|
M 102.920, M 102.939
|
M 102.980, M 102.982
|
M 115.954
|
|
Thickness of an insert of the radical bearing | ||||
nominal |
2,25 |
2,25 |
2,25 |
|
1st repair size |
2,37 |
2,37 |
2,37 |
|
2nd repair size |
2,50 |
2,50 |
2,50 |
|
3rd repair size |
2,62 |
2,62 |
2,62 |
|
4th repair size |
2,75 |
2,75 |
2,75 |
|
Thickness of an insert of the conrod bearing | ||||
nominal |
1,80 |
1,80 |
||
1st repair size |
1,92 |
1,92 |
||
2nd repair size |
2,05 |
2,05 |
||
3rd repair size |
2,17 |
2,18 |
2,17 |
|
4th repair size |
2,30 |
2,30 |
||
Parameter, mm
|
M 123.920, M 123.921
|
M 110.923
|
M 110.984, M 110.988
|
|
Thickness of an insert of the radical bearing | ||||
nominal |
3,50 |
|||
1st repair size |
3,63 |
|||
2nd repair size |
3,75 |
|||
3rd repair size |
3,88 |
|||
4th repair size |
4,00 |
|||
Thickness of an insert of the conrod bearing | ||||
nominal |
1,81 |
|||
1st repair size |
1,93 |
|||
2nd repair size |
2,06 |
|||
3rd repair size |
2,18 |
|||
4th repair size |
2,31 |
Flywheel of the engine M 102
The flywheel fastens eight bolts. The adjusting opening is opposite to drilling in a bent shaft.
Characteristic |
Value |
Diameter of the aligning fillet of a wreath, mm |
275,31 — 275,39 |
Distance between a working surface of the conducted disk and a basic surface of a casing of coupling, mm |
22,5 — 22,6 |
Distance between a working surface of the conducted disk and a head of a bolt of fastening of a flywheel, mm |
|
|
16,6 |
|
15,5 |
Not planeness of a working surface of the conducted clutch plate, no more, than a mm |
0,05 |
Outer diameter of a working surface of the conducted clutch plate, mm |
222,0 |
Outer diameter of a basic surface of a casing of coupling, mm |
253,0 |
Diameter of a core of compensation bolts of fastening of a flywheel, mm |
|
|
8,5 |
|
8,0 |
Bolt length to a head, mm |
|
|
22±0,2 |
|
22,5 |