2.10.12. Shatunno-piston group
|Fig. 2.504. Piston and rod components: 1 – a bolt of fastening of a cover of a rod – 30 Нм + to tighten on 90 (1/4 about.); 2 – a rod cover; 3 – the bearing loose leaf; 4 – a rod; 5 – a lock ring; 6 – a piston finger; 7 – the piston; 8 – piston rings; 9 – a piston ring
Check of a thermal backlash of piston rings
|Fig. 2.133. Check of a thermal backlash of a piston ring
Drive a piston ring from above, at right angle to a cylinder wall, to the bottom aperture of the cylinder, on distance about 15 mm from its edge (fig. 2.133
For installation use the piston without rings.
Check of a backlash of piston rings on height
Before check clear a ring flute of the piston.
Check of pistons
Measure approximately in 10 mm from a bottom edge, at right angle to an axis of a piston finger.
Max. A deviation from the nominal size: 0,04 mm
Adjusting position and compatibility the piston/cylinder
|Fig. 2.505. Marks of adjusting positions of pistons
The arrow specifies in the piston bottom towards belt pulleys (fig. 2.505
Check of diameter of the cylinder
|Fig. 2.135. The scheme of check of diameter of the cylinder
Spend measurements with the help нутромера
50–100 mm in 3 places cross-wise in a cross-section direction And and in a longitudinal direction In (fig. 2.135
Max. A deviation from the nominal size: 0,10 mm
Adjusting position of loose leaves of bearings in rods
|Fig. 2.506. Adjusting position of loose leaves of bearings in rods
To insert loose leaves of bearings follows in a rod or a rod cover in the middle.
Distance And = 2,5 mm.
Check выступания pistons in the top dead point
|Fig. 2.507. Check выступания pistons in the top dead point
At installation of new pistons or a new component of the engine check up выступание all pistons in ВМТ.
Depending on выступания pistons establish a corresponding lining of a head of the cylinder according to the following table.
Marks of a lining of a head of the block of cylinders
|Fig. 2.508. Marks of a lining of a head of the block of cylinders: 1 – number under the catalogue of spare parts; 2 – a management code; 3 – apertures
If at measurement выступания pistons various values have been received, for compatibility with consolidation use the greatest size.
The sizes of pistons and cylinders
Check of radial palpation of rods
Remove covers of rods.
Clear covers of bearings and a neck.
Put thread Plastigage according to width of the bearing on a radical neck and in loose leaves of bearings.
Put covers of rods and fasten with the moment 30 Нм, do not turn crankshaft.
Again remove covers of rods.
Compare width of measuring strip Plastigage to a scale.
The limiting admission of 0,08 mm.
Replace bolts of rods.