If complete disassembly of the cylinder thoroughly clean the cylinder block and remove all foreign objects from the cavities and oil channels. Make sure that was completely removed for cleaning liquid, if possible, use compressed air. For measuring cylinder requires a special dial indicator (see. Graphic below), by which to measure the middle and lower portion.
| || Measuring cylinder of an internal micrometer. |
If the indicator is not present, the following operation can not be performed. The measurements should be made of cylinders in the longitudinal and transverse directions (Figure below). Also note the difference between injected and carbureted engine.
| || The diagram of measurements of the cylinder. Make measurements at levels A, B and C in the direction of "XX" and "YY". |
- On fuel-injected engine measurement should be carried out according to the above illustration, t. E. 10 mm, 60 mm and 100 mm from the upper edge. Make measurements in the directions "X" and "Y".
- On the carburettor engine the first measurement is made in 20 mm from the top edge of the cylinder, and the rest as in the previous paragraph.
- Total required 6 measurements per cylinder. Write down all the values and compare with values in the Specifications in the beginning of Chapter. Through precise measurements determined roundness (the difference between the dimensions "A" and "B") and taper (the difference between the values of the upper and lower measurement). Keep in mind that must be chiseled all cylinders, even if only one cylinder is out of range. Deviation from desired dimensions 0.04 mm is acceptable. Repair size pistons are available in the Specifications in the beginning of Chapter. The final diameter of the cylinders is determined by measuring the piston as illustrated below t. E. Micrometers grippers are set in 9.5 mm (petrol engine) or 11.0 mm (injection engine) from the lower edge of the piston at 90 ?° piston pin. To this, add the size of the gap value 0.010 - 0.030 mm (injection engine) or 0.015 - 0.035 mm (petrol engine). Also, you should take into account the addition of 0.02 mm for final polishing of the cylinder. To check the clearance pistons measure piston and cylinder as previously described and compute the difference between the dimensions of each cylinder.
| || Measure the diameter of the piston. The size of "a" for injection and carburetor engine is not the same. |
- If you have no experience in the measurement, the unit should be referred to a special workshop to produce the measurement there.
For clarity, you can draw a sketch and record the measurements there. The difference between the upper and lower measurements reflect the taper. The difference between transverse and longitudinal dimensions reflect roundness. Nowhere diameter should not differ from the specified value greater than 0.04 mm.
- On the upper surface of the cylinder knocked numbers that indicate the size class of the pistons. When replacing the cylinder pistons must be installed the appropriate class sizes. Check the surface of the cylinder for deformation, as shown in the illustration below.
Measurement of deformation of the surface of the cylinder
| || 1 - probe |
2 - steel ruler
- To apply this to the surface of a steel ruler unit (2) and measure the gap via the probe (1). Measure the block in the transverse and longitudinal directions of the diagonal, as shown on the small figure. The maximum allowable size of 0.10 mm. It should be remembered that the head and the cylinder block can be abraded in total not more than 0.2 mm. If the head is not necessary to grind, check the height of the cylinder head, the size specified in the Specifications in the beginning of Chapter. If the cylinder block after grinding has a height less than the permitted, it must be replaced.