Chain tension is adjusted by a hydraulic tensioner with lock.
Aluminum alloy camshaft cover.
Valve timing
The calculation of the valve timing is given with a zero design valve clearance and a valve lift of 2 mm.
In parentheses is the value after a run of 20,000 km.
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 the opening of the intake valve to the TDC advance of the intake stroke | 14,0 | 11,0 (12,0) | 11,0 (12,0) | 14,0 |
Intake valve closing after BDC of the compression stroke with delay | 20,0 | 17,0 (18,0) | 17,0 (18,0) | 27,0 |
The beginning of the opening of the exhaust valve to BDC advance stroke | 22,0 | 32,0 (31,0) | 32,0 (31,0) | 36,5 |
Closing the exhaust valve after the TDC exhaust stroke with a delay | 12,0 | 13,0 (12,0) | 13,0 (12,0) | 18,50 |
Camshaft marking | 5 | 12 | 23 | 13 |
Parameter, mm | M 123.920, M 123.921 | M 110.923 | M 110.984, M 110.988 | |
The beginning of the opening of the intake valve to the TDC advance of the intake stroke | 15,0 | 7,0 | 7,0 | |
Intake valve closing after BDC of the compression stroke with delay | 21,0 | 21,0 | 21,0 | |
The beginning of the opening of the exhaust valve to BDC advance stroke | 21,0 | 30,0 | 30,0 | |
Closing the exhaust valve after the TDC exhaust stroke with a delay | 11,0 | 12,0 | 12,0 | |
Camshaft marking | 02 | right: 57 | 71 |
Camshafts
Five- (engines M 102 and M 115) or semi-support (engines M 110 and M 123) hollow camshaft. The front end of the shaft is closed with a sprocket bolt, and the rear end is closed with a steel plug. Oil enters the shaft channel through the groove and hole in the rear support and provides lubrication to the support shaft. A digital mark is stamped on the end face of the sprocket mounting flange on the shaft.
Characteristics of camshafts
The stretching of the timing chain can be compensated for by moving the camshaft sprocket.
Characteristic | Meaning |
Permissible radial runout of the camshaft journals, mm | 0,025—0,030 |
Cleanliness of the surface of the camshaft bearing support, microns | 0,003 |
Displacement of an asterisk of a camshaft, mm | Amendment |
0,7 | 6° |
0,9 | 8° |
1,1 | 9,5° |
1,3 | 11,5° |
Clearances in the valve drive mechanism on a cold and hot engine for intake and exhaust valves are shown in the table. Valve clearances are not adjustable on engines with hydraulic valve clearance compensation.
The bearings are not heat treated. The 1st support of the M 110 engine is not polished, a sleeve is installed on it.
Parameter, mm | Engine model | |||
M 115.938 | M 102.920, M 102.939 | M 102.980, M 102.982 | M 115.954 | |
On a cold engine | ||||
| 0,10 | 0,15 | 0,15 | 0,10 |
| 0,20 | 0,20 | 0,20 | 0,20 |
On a warm engine (oil temperature 45-75°C) | ||||
| 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 a cold engine | ||||
| 0,10 | 0,10 | 0,10 | |
| 0,20 | 0,25 | 0,25 | |
On a warm engine (oil temperature 45-75°C) | ||||
| 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 | ||||
Shaft journal diameter | ||||
| 34,959—34,975 | 31,934—31,950 | 34,959—34,975 | |
| 34,859—34,875 | * | 34,859—34,875 | |
| 34,709—34,725 | 32,434—32,450 | 34,709—34,725 | |
Support hole diameter | ||||
| 35,000—35,016 | 32,000—32,025 | 35,000—35,016 | |
| 34,900—34,916 | * | 34,900—34,916 | |
| 34,750—34,766 | 32,500—32,525 | 34,750—34,766 | |
Supports 2 and 3 | ||||
Shaft journal diameter | ||||
| 48,959—48,975 | — | — | 48,959—48,975 |
| 48,859—48,875 | — | — | 48,859—48,875 |
| 48,709—48,725 | — | — | 48,709—48,725 |
Support hole diameter | ||||
| 49,000—49,016 | — | — | 49,000—49,016 |
| 48,900—48,916 | — | — | 48,900—48,916 |
| 48,750—48,766 | — | — | 48,750—48,766 |
Support 4 | ||||
Shaft journal diameter | ||||
| — | — | — | — |
| — | — | — | — |
| — | — | — | — |
Support hole diameter | ||||
| — | — | — | — |
| — | — | — | — |
| — | — | — | — |
Support 5 | ||||
Shaft journal diameter | ||||
| — | — | — | — |
| — | — | — | — |
| — | — | — | — |
Support hole diameter | ||||
| — | — | — | — |
| — | — | — | — |
| — | — | — | — |
Support 6 | ||||
Shaft journal diameter | ||||
| — | — | — | — |
| — | — | — | — |
| — | — | — | — |
Support hole diameter | ||||
| — | — | — | — |
| — | — | — | — |
| — | — | — | — |
Support 7 | ||||
Shaft journal diameter | ||||
| — | — | — | — |
| — | — | — | — |
| — | — | — | — |
Support hole diameter | ||||
| — | — | — | — |
| — | — | — | — |
| — | — | — | — |
Parameter, mm | M 123.920, M 123.921 | M 110.923 | M 110.984, M 110.988 | |
Support 1 | ||||
Shaft journal diameter | ||||
| 34,93—34,95 | 23,98—23,99 | ||
| 34,83—34,85 | * | ||
| 34,68—34,70 | * | ||
Support hole diameter | ||||
| 35,00—35,02 | 38,00—38,02* | ||
| 34,90—34,92 | * | ||
| 34,75—34,77 | * | ||
Supports 2 and 3 | ||||
Shaft journal diameter | ||||
| 48,93—48,95 | 49,93—49,94 | ||
| 48,83—48,85 | 49,68—49,70 | ||
| 48,68—48,70 | 49,43—49,45 | ||
Support hole diameter | ||||
| 49,00—49,02 | 50,05—50,07 | ||
| 48,90—48,92 | 49,80—49,82 | ||
| 48,75—48,77 | 49,55—49,57 | ||
Support 4 | ||||
Shaft journal diameter | ||||
| 49,93—49,95 | 49,93—49,95 | ||
| 49,83—49,85 | 49,68—49,70 | ||
| 49,69—49,70 | 49,43—49,45 | ||
Support hole diameter | ||||
| 50,00—50,02 | 50,00—50,02 | ||
| 49,90—49,92 | 49,75—49,77 | ||
| 49,75—49,77 | 49,50—49,52 | ||
Support 5 | ||||
Shaft journal diameter | ||||
| — | 51,42—51,44 | ||
| — | 51,17—51,19 | ||
| — | 50,92—50,94 | ||
Support hole diameter | ||||
| — | 51,50—51,52 | ||
| — | 51,25—51,27 | ||
| — | 51,00—51,02 | ||
Support 6 | ||||
Shaft journal diameter | ||||
| — | 52,92—52,94 | ||
| — | 52,67—52,69 | ||
| — | 52,47—52,49 | ||
Support hole diameter | ||||
| — | 53,00—53,02 | ||
| — | 52,75—52,77 | ||
| — | 52,50—52,52 | ||
Support 7 | ||||
Shaft journal diameter | ||||
| — | 53,92—53,94 | ||
| — | 53,67—53,69 | ||
| — | 53,43—53,45 | ||
Support hole diameter | ||||
| — | 54,00—54,02 | ||
| — | 53,75—53,77 | ||
| — | 53,50—53,52 |
* The bushing of the 1st support has an outer diameter of 37.93–37.95 mm and an inner diameter of 24.00–24.01 mm.
Hydraulic Tensioner
The pusher piston, under the influence of oil pressure in the engine lubrication system and the internal spring, constantly acts on the tensioner shoe.
Characteristic | Meaning |
Oil supply hole diameter, mm | 1,1 |
Oil outlet diameter, mm | 1,2 |