The following data is stamped on the piston bottom:
1 - piston class by pin hole (1, 2, 3)
2 - piston class by diameter (A, B, C, D, E)
3 - arrow showing the direction of piston installation
4 - group by weight (normal - "G", increased by 5 g - "+", decreased by 5 g - "-")
5 - repair size (diameter increased by 0.4 mm - D, by 0.8 - E)
Cylinder class (A, B, C, D, E) stamped on the lower plane of the block (mating plane under the oil pan).
Piston selection
For ease of selection of pistons for cylinders by diameter, both are divided into five classes: A, B, C, D, E (through 0.1 mm). Spare parts are supplied in the form of pistons of nominal size of three classes A, C, E and two repair sizes. The first repair size is increased by 0.4 mm, the second by 0.8 mm.
According to weight, pistons are divided into three groups: normal, increased by 5 g and decreased by 5 g. Pistons of the same group must be installed on the engine.
For pistons of repair sizes, rings of repair sizes increased by 0.4 and 0.8 mm are supplied as spare parts. The rings of the first repair size are stamped with the number "40", and the second - "80".
Nominal dimensions of cylinder and piston diameters, mm
| Size group | Engine VAZ-1111 | Engine VAZ-11113 | ||
| Cylinder | Piston | Cylinder | Piston | |
| A B C D E | 76,00-76,01 76,01-76,02 76,02-76,03 76,03-76,04 76,04-76,05 | 75,965–75,975 75,975–75,985 75,985–75,995 75,995–76,005 76,005–76,015 | 82,00–82,01 82,01–82,02 82,02–82,03 82,03–82,04 82,04–82,05 | 81,965–81,975 81,975–81,985 81,985–81,995 81,995–82,005 82,005–82,015 |
When selecting pistons for cylinders, determine the clearance between them as the difference between the measured diameters of the piston and cylinder.
Cylinder measurement diagram:
A and B are the directions of measurements
1, 2, 3 and 4 - belt numbers
The nominal clearance is set at 0.025-0.045 mm, the maximum allowable is 0.15 mm. If the clearance does not exceed 0.15 mm, pistons from the following classes can be selected so that the clearance is as close to the nominal as possible. If the clearance exceeds 0.15 mm, bore the cylinders to the next repair size and install pistons of the corresponding repair size. Both cylinders are bored to the repair size, even if the clearance between the piston and the cylinder exceeds the maximum allowable only in one cylinder.
Piston pins are divided by diameter into three classes (1, 2, 3) through 0.004 mm. The pin class is marked on its end with paint. The piston class by pin is stamped on the piston bottom, and the connecting rod class by pin is on the connecting rod cover.
Size classes of piston pins and pistons
| Class | Diameter, mm | Marking | ||
| fingers | holes in the piston | fingers | piston | |
| 1 2 3 | 21,970–21,974 21,974–21,978 21,978–21,982 | 21,982–21,986 21,986–21,990 21,990–21,994 | Blue Green Red | 1 2 3 |
106. Clean the piston head from carbon deposits.
107. Clean the grooves for the piston rings. It is convenient to do this with a piece of an old ring.
108. Clean the oil drain holes with wire of appropriate thickness.
109. If the piston has scoring, burn marks, deep scratches, or cracks, replace the piston.
110. Check the clearance between the rings and the piston grooves. To do this, use a set of feeler gauges to measure the width of the grooves in several places around the circumference, and then...
111....measure the thickness of the rings in several places around the circumference with a micrometer. Calculate the average gap values (difference between ring thickness and groove width). If at least one of the gaps exceeds the maximum permissible value, replace the piston with rings.
Explanation of operations 110 and 111
Nominal clearance, mm:
- for the upper compression ring 0.04-0.075;
- lower compression ring 0.03-0.065;
- oil scraper ring 0.02-0.055.
The maximum permissible gap for all rings is 0.15 mm.
112. Measure the gaps in the ring locks. This can be done by inserting the ring into a special mandrel. If there is no mandrel, insert the ring into the cylinder (in which it worked), push the piston, like a mandrel, into the cylinder so that it fits in without distortion, remove the piston from the cylinder and...
113....measure the gap in the ring lock with a feeler gauge. The nominal gap should be 0.25-0.45 mm, the maximum permissible (due to wear and tear) - 1.0 mm. If the gap exceeds the maximum permissible value, replace the ring.
114. If the gap is less than 0.25 mm, carefully file down the ends of the ring.
115. Inspect the cylinders. If there are scratches, burrs, cavities, etc. on the cylinder mirror, bore the cylinders to the repair size or replace the cylinder block. If such defects are more than 0.8 mm deep, the block cannot be repaired and must be replaced.
116. Clean the carbon deposits from the top of the cylinders. If a belt has formed there due to cylinder wear, remove it with a scraper. Blunt the sharp edges on the cylinder block plane with a scraper...
117....and then with fine sandpaper. Measure the cylinder diameter in two perpendicular planes with a bore gauge (along and across the axis of the cylinder block) and four belts.
118. Measure the piston diameter at a distance of 51.5 mm from its bottom in a plane perpendicular to the piston pin. Calculate the clearances between the pistons and cylinders.
119. Inspect the connecting rod bearings. If they have cracks, scoring, or chipping, replace the bearings. It is prohibited to carry out any adjustment work on the bearings.
120. If there are deep grooves, scratches, nicks on the surfaces of the crankshaft on which the seals operate, the crankshaft must be replaced.
121. If there are minor nicks, scratches or marks on the main and connecting rod journals, they need to be ground down to the nearest repair size (in a specialized workshop). After that...
122.... polish the journals and blunt the sharp edges of the oil channel chamfers with an abrasive cone. Then wash the crankshaft and blow out the oil channels with compressed air. The ovality and taper of all journals after grinding should not exceed 0.005 mm. After grinding the journals, install liners of repair dimensions.
123. Measure the main and connecting rod journals of the crankshaft. If the wear or ovality of the journals exceeds 0.03 mm, they must be ground to the nearest repair size.
124. If there are burrs, scratches and delaminations on the working surfaces of the thrust half rings, replace the half rings. It is prohibited to carry out any adjustment work on the half rings.
Selection of crankshaft liners
Nominal diameter of crankshaft journals, mm:
- indigenous 50,799-50,819
- connecting rod 47.830-47.850
The crankshaft journals can be ground to one of four repair sizes with a reduction in the nominal journal diameter, mm:
- first by 0.25 third by 0.75
- second by 0.5 fourth by 1.00
Nominal thickness of liners, mm:
- indigenous 1,824-1,831
- connecting rod 1.723-1.730
The liners are also supplied as spare parts in four repair sizes, with increased thickness, mm:
- first by 0.25 third by 0.75
- second by 0.5 fourth by 1.00
Clearances between liners and crankshaft journals, mm:
- for main bearings: nominal - 0.026-0.073, maximum permissible - 0.11;
- for connecting rod bearings: nominal - 0.02-0.07, maximum permissible - 0.1.
The crankshaft runout should be, mm:
- on the middle main journal and the seating surface under the drive gear of the oil pump - no more than 0.03;
- on the landing surface under the flywheel - no more than 0.04;
- on the seating surface under the pulleys and seals and under the balance shaft drive gear - no more than 0.05.
Dimensions of half rings supplied as spare parts: nominal - 2.31-2.36 mm and repair (increased by 0.127 mm) - 2.437-2.487 mm.
Axial clearance of the crankshaft: nominal - 0.06-0.26 mm, maximum permissible - 0.35 mm.
Original source is on the resource [vazbook.ru]
125. Measure the axial clearance of the crankshaft. To do this, install the crankshaft and thrust half rings in the cylinder block and tighten the bolts securing the main bearing caps. Install the flywheel. Secure the indicator so that its leg rests on the working surface of the flywheel (contact with the driven clutch disc). Move the crankshaft down until it stops (from the indicator) and set the indicator arrow to zero. Move the shaft in the opposite direction. The indicator will show the gap value. If the gap exceeds the maximum permissible value, replace the thrust half rings.
126. Inspect the main bearings. If they have cracks, scoring, or chipping, replace the bearings. It is prohibited to carry out any adjustment work on the bearings.
127. Thoroughly clean and flush the crankshaft oil passages. While doing this...
128....it is not recommended to press out the plugs yourself (to do this, contact a specialized workshop).
129. Carefully clean the cylinder block surfaces from the remains of old sealing gaskets. Carefully inspect the block. If you find cracks, replace the block together with the main bearing caps.
130. Check the tightness of the cylinder block cooling jacket. To do this, plug the hole under the water pump (install the pump with the gasket) and pour Tosol A-40 into the cooling jacket. If you notice a leak somewhere, it means the block is not sealed and needs to be replaced.
Explanation
The non-flatness of the surface where the driven clutch disc contacts must not exceed 0.05 mm.
The non-parallelism of the surface c for contact with the driven clutch disc and the surface b for fastening the clutch relative to the surface a adjacent to the crankshaft flange must not exceed 0.1 mm.
The flywheel runout on surfaces b and c must not exceed 0.1 mm.
To remove deep scratches and burrs, the flywheel surface can be turned, while the layer of metal removed should not exceed 1 mm. Simultaneously with surface c, it is necessary to turn surface b, maintaining the size between them of 0.5 0.1 mm. When turning, maintain the parallelism of surfaces a, b and c.
The toothed ring on the flywheel should not rotate when a torque of 600 N·m (60 kgf/m) is applied to it and should not shift in the axial direction when a force of 4000 N (400 kgf) is applied to it.
131. Check the clearances between the main bearing shells and the crankshaft journals. To do this, measure the diameter of the journals, and then the diameter of the main bearings, installing the covers with the shells on the block and tightening them to the appropriate torques. Calculate the clearance. If it exceeds the maximum permissible, the crankshaft must be ground to the next repair size. It is recommended that this work be performed in a specialized workshop.
132. Check the condition of the rear crankshaft oil seal. Replace the oil seal if it is damaged (cracked), has a worn working edge, or has lost elasticity.
133. The rear crankshaft oil seal holder must not have any cracks or severe deformations of the mating surface to the cylinder block.
134. Check the condition of the flywheel ring gear teeth and replace the flywheel if they are damaged.
135. Replace or repair the flywheel if the clutch disc mating surfaces or...
136....there are scratches and scoring marks on the crankshaft flange.
137. If the mating surface of the driven clutch disc shows discoloration (the flywheel was overheated), then perhaps the fit of the toothed ring on the flywheel is not tight enough. This can be checked in a specialized workshop. A flywheel with a loose fit of the toothed ring must be replaced.