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Measuring the working air gap in the pistons
To determine the working gap pistons need to fathom their diameters and record the results. To determine the gap should be measured diameters of cylinder liners, as described below.
| Fig. 55. Designated metering holes of cylinder liners: A - measured in the longitudinal axis of the engine; In - measured in the transverse axis of the engine; and - the highest point of stopping the top piston ring; b - lower stop point of the piston; from - the lowest point of stopping oil ring; 1, 2, 3 - Measuring point
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Using callipers to measure the diameter of the cylinder, as shown in Fig. 55. Measurements are carried out in the longitudinal and transverse axes of the engine block and the cylinder at equal depths. All six of the results recorded accurately. The difference in the results of measurements in the upper and lower part of the cylinder indicates its conicity. The difference in the results as measured in the longitudinal axis, and as measured in the transverse axis indicates the roundness of the cylinder bores. None of the six measuring points cylinder diameter must not deviate by more than a predetermined 0.12mm. For each engine are provided removable cylinder liners, which are press-fit into the engine block should be carried out in the workshop. Gasket surfaces of the cylinder must be checked for deformation similar to the mating surface of the cylinder head. Conduct measurements in the longitudinal, transverse and diagonal directions at a ruler, Establishing the gasket surface of the cylinder. Probe thickness greater than 0.10 mm should not be held under the line at any point of the surface.
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