The permissible deviation from the nominal size is 0.04 mm. It should be noted 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 table 1.
The final repair size of the cylinder is determined as follows: the piston diameter is measured (see figure 72) 15 from the lower edge of the skirt perpendicular to the axis of the hole for the pin. To this size is added the value of the piston clearance of 0.03. It should be taken into account that a reserve of 0.02 is required for final honing.
To check the clearance between the piston and the cylinder, you need to measure the diameters of the piston and cylinder in the manner described above and get the difference between these dimensions. If the result exceeds 0.08 mm, then the cylinders must be ground, since the clearance has already exceeded the maximum permissible value. Based on the obtained results of measuring the diameters of the cylinders, you can plot a graph (see figure 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 the perpendicular ones - the ovality of the cylinder. The cylinder diameter should not exceed the nominal by more than 0.04 mm.
Additionally, it is necessary to check the cylinder block for warpage in the same way as was described for the cylinder head. Measurements should be taken in the longitudinal, perpendicular and diagonal directions. The maximum permissible warpage is 0.1 mm.
(The information is presented on the website: «www.VWManual.ru»)
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