To determine the degree of wear of the cylinder mirror, a caliper is required (see fig. 71). Diameter measurements are made in two planes and in three sections along the height of the cylinder by the method described here.
The permissible deviation from the nominal size is 0.04 mm. Special attention should be paid to the fact that if at least one of the cylinders is worn out, all cylinders are subject to repair. The dimensions of the repair pistons are given in tab. 1.
The final repair size of the cylinder is determined as follows: measure the piston diameter (see fig. 72) 15 from the bottom edge of the skirt perpendicular to the axis of the finger hole. To this dimension is added a piston clearance of 0.03 Note that a margin of 0.02 is required for final honing.
To check the gap between the piston and the cylinder, you need to measure the diameters of the piston and cylinder in the previously described way and get the difference between these dimensions. If the result exceeds 0.08 mm, then the cylinders must be ground, since the gap has already exceeded the maximum allowable value. Based on the results of measuring cylinder diameters, a graph can be plotted (see fig. 80), by which it is easy to determine the degree of wear of the cylinder. The difference between the measurement result in the upper and lower sections determines the taper, between perpendicular - the ovality of the cylinder. The cylinder diameter must not exceed the nominal diameter by more than 0.04 mm.
Additionally, it is necessary to check the cylinder block for warping in the same way that was given for the cylinder head. Measurements should be made in the longitudinal, perpendicular and diagonal directions. The maximum allowable warp value is 0.1 mm.
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