To do the job, you will need a caliper.
Execution sequence
1. We prepare the car for work (see "Preparing the car for maintenance and repair").
2. Remove the pistons from the cylinder block (see "Piston rings and connecting rod bearings - replacement").
Comment. For how to use the caliper, see the enclosed instructions or specialist literature.
3. With a bore gauge, we check the wear of the cylinder walls.
Measurements are carried out in four belts (5, 12, 62 and 112 mm from the top edge of the cylinder) in the longitudinal and transverse directions of the engine. In the upper belt, the cylinder does not wear out. By the difference in readings of the caliper in different belts, we determine the degree of wear of each cylinder.
Engine cylinder diameters are divided into five size classes (see table. 8.4). The class of each cylinder is stamped on the lower mating surface of the cylinder block.
Table 8.4. Classes of cylinders by diameter
Designation |
Diameter, mm |
A |
82,00-82,01 |
B |
82,01-82,02 |
C |
82,02-82,03 |
D |
82,03-82,04 |
E |
82,04-82,05 |
Recommendation. Small uniform cylinder wear (within 0.05mm) can be compensated by installing a piston of a different class with a larger diameter.
If the maximum wear is 0.15 mm or more, it is necessary to bore the cylinders and install oversized pistons.
Cylinder bore of 0.4 mm and 0.8 mm is provided for the dimensions of the repair pistons.
4. On the bottom of the piston are marked, where:
- Class 2 hole for the piston pin;
- C class piston;
- ← mark, which should be directed towards the front end of the crankshaft;
- G piston mass group.
According to the diameter of the hole for the piston pin, pistons are divided into three classes (1, 2, 3) through 0.004 mm.
The outer diameter of the pistons are divided into five classes (A, B, C, D, E) through 0.01 mm (measured in a plane perpendicular to the piston pin at a distance of 55 mm from the piston crown).
The size of the pistons are nominal and two repair sizes. Nominal size pistons are not marked. Pistons of the first repair size are manufactured with a diameter increased by 0.4 mm and are marked with a symbol "Δ". Pistons of the second repair size have a diameter increased by 0.8 mm and are marked with the symbol "□".
On the engine, all pistons must be of the same mass group. Pistons of the nominal group are indicated by the symbol "G". Pistons with an increased and reduced mass of 5 g are indicated "+" And "-" respectively.
The class of the finger is marked with paint on its end.
According to the outer diameter, the fingers are divided into three classes (blue, green and red), through 0.004 mm.
To facilitate the selection of a finger to the piston bore, the required class of the finger is indicated on its inner side with paint.
The required pin class is indicated on the connecting rod cap (number 2). By the mass of the heads, the connecting rods are divided into classes. The marking is applied on the connecting rod cap with the letter "M"...
...or paint.
Connecting rods of the same weight class must be installed on the engine (see table. 8.5).
Table 8.5. Mass classes of connecting rods
Mass of connecting rod heads, g |
Class |
Marking color |
|
Upper |
Lower |
||
184+2 |
489+3 |
F |
Red |
495+3 |
L |
Green |
|
501+3 |
B |
No |
|
188+2 |
489+3 |
X |
No |
495+3 |
M |
No |
|
501+3 |
IN |
No |
|
192+2 |
489+3 |
c |
No |
495+3 |
n |
No |
|
501+3 |
G |
Blue |
Warning! On 2111 engines, the parts of the connecting rod and piston group with a floating pin are not interchangeable with the parts of the connecting rod and piston group with a pressed pin. Any of the two connecting rod and piston groups can be installed in the same cylinder block. The use of a connecting rod and piston group with a floating pin is preferable.