Characteristic | Meaning |
Cylinder head height, mm | |
M 115 | |
| 84,8—85,0 |
| 83,8 |
M 102 | |
| 98,5—98,4 |
| 97,8 |
M 123 | |
| 84,8—85,0 |
| 84,0 |
M 110 | |
| 93,9—94,0 |
| 93,1 |
Warping of the mating plane of the head with the cylinder block in the longitudinal / transverse directions, no more than, mm | |
M 102 | 0,10 |
M 115 | 0,08 |
M 110 | 0,08 |
M 123 | 0,08 |
Main technical characteristics
Model | Cylinder diameter x piston stroke, mm | Working volume, cm3 | Rated power «net», kW (hp) / at the frequency of rotation of the crankshaft, rpm | Maximum torque, N.m (kgf.m) / at the frequency of rotation of the crankshaft, rpm | Compression ratio |
M 115.938 | 87x83,6 | 1997 | 70 (94) /4800 | 158 (16,1) /3000 | 9 |
M 102.920 | 89x80,25 | 1997 | 74 (100) /5500 | 160 (16,3) /3000 | 8 |
M 102.939 | 89x80,25 | 1997 | 80 (109) /5100 | 172 (17,5) /3500 | 9 |
M 102.980* | 95,5x80,25 | 2299 | 100 (136) /5100 | 205 (20,9) /3500 | 9 |
M 102.982* | 95,5x80,25 | 2299 | 92 (125) /5000 | 194 (19,8) /3500 | 8 |
M 115.954 | 93,75x83,6 | 2307 | 80 (109) /4800 | 185 (18,9) /3000 | 8 |
M 123.920 | 86x72,45 | 2525 | 74 (100) /5200 | 183 (18,7) /3000 | 8,4 |
M 123.921 | 86x72,45 | 2525 | 103 (140) /5500 | 196 (20,0) /3500 | 9,4 |
M 110.923 | 86x78,8 | 2746 | 115 (156) /5500 | 226 (23,0) /4000 | 9 |
M 110.984 | 86x78,8 | 2746 | 125 (170) /5500 | 224 (22,8) /4500 | 8 |
M 110.988 | 86x78,8 | 2746 | 136 (185) /6000 | 240 (24,5) /4500 | 9 |
* Engines of models M 102.980 and M 102.982 have the same serial number (M 102.E23) and differ in the degree of compression and the grade of fuel used.
Longitudinal section of the engine M 102
Cross section of the M 102 engine
Valves
Characteristic | Meaning |
Engine valve diameter, mm | |
M 102.985 | |
| 41,0 |
| 37,0 |
Roughness of the mating plane of the head with the cylinder block, microns | |
M 102 | 0,005—0,020 |
M 115 | 0,012—0,020 |
M 110 | 0,012—0,020 |
M 123 | 0,012—0,020 |
Length of bolts of fastening of a head of cylinders, mm | |
M 102 | |
| 119,0 |
| 122,0 |
M 115 | |
| 119,0 |
| 122,0 |
M 110 | |
| 160,0 |
| 162,7 |
M 123 | |
| 160,0 |
| 162,7 |
Valve seats
Valve seats are plug-in.
Characteristic | Meaning |
Chamfer angle, deg. | 45 +0 —15 0 |
Upper cone angle, deg. | 30 |
Lower cone angle, deg. | 60 |
Working chamfer width, mm | |
M 102 | |
| 1,8—2,5 |
| 1,5—2,5 |
M 115 | |
| 2,0—2,1 |
| 1,5—2,5 |
M 110 | |
| 2,3—2,5 |
| 1,5—2,5 |
M 123 | |
| 2,3—2,5 |
| 1,5—2,5 |
When using unleaded gasoline, stronger valve seats must be installed.
Characteristics of saddles of inlet valves
Size, mm | Engine model | |||
M 115.938 | M 102.920, M 102.939 | M 102.980, M 102.982 | M 115.954 | |
Valve seat diameter | ||||
nominal | 48,500—48,516 | 46,000—46,016 | 46,000—46,016 | 48,500—48,516 |
repair size (no more) | 49,000 | 47,000 | 49,000 | |
Outside diameter of seats | ||||
nominal | 48,590—48,600 | 46,090—46,100 | 48,590—48,600 | |
repair size (no more) | 49,80 | 47,30 | 49,0800 | |
Seats inside diameter | ||||
— | 37,0 | — | ||
Saddle height | ||||
10,29—10,40 | 7,980—8,000 | 10,89—11,00 | ||
Preload when pressing in the intake and exhaust valve seats | ||||
0,08—0,10 | 0,074—0,10 | 0,08—0,10 | ||
Size, mm | M 123.920, M 123.921 | M 110.923 | M 110.984, M 110.988 | |
Valve seat diameter | ||||
nominal | 42,700—42,716 | 47,000—47,016 | 47,000—47,016 | |
repair size (no more) | 43,700 | 48,018 | ||
Outside diameter of seats | ||||
nominal | 42,790—42,800 | 47,090—47,100 | ||
repair size (no more) | 44,0 | 48,30 | ||
Seats inside diameter | ||||
— | — | — | ||
Saddle height | ||||
10,89—11,00 | 8,51—8,6 | |||
Preload when pressing in the intake and exhaust valve seats | ||||
0,08—0,10 |
Valve guides
The valve guides are plug-in, pressed into the cylinder head.
Characteristic | Meaning |
Preload, mm | 0,012—0,013 |
Pressing force, kgf.m | 300,0—350,0 |
Valve guide specifications
Parameter, mm | Inlet valve guides | ||
nominal size | 1st repair size | 2nd repair size | |
Label color | Grey-green | Red | White |
Grey | |||
taupe | |||
Outside diameter | 14,03—14,05 | 14,21—14,23 | 14,41—14,43 |
Inner diameter | 9,00—9,015 | ||
Guide bush hole diameter | 14,02 | 14,20—14,22 | 14,40—14,42 |
Length | 55,0 | ||
Limit wear | 9,025 | ||
Parameter, mm | Exhaust valve guides | ||
nominal size | 1st repair size | 2nd repair size | |
Label color | Grey-green | Red | White |
Grey | |||
taupe | |||
Outside diameter | 15,03—15,05 | 15,21—15,23 | 15,41—15,43 |
Inner diameter | 11,000—11,018 | ||
Guide bush hole diameter | 15,02 | 15,20—15,22 | 15,40—15,42 |
Length | 45,0 | ||
Limit wear | 11,030 |