2. Inspect the block for cracks and corrosion. Check the threads in the threaded holes. It is useful to check the block for hidden cracks, especially if it has been overheated during operation or if internal coolant leaks have been observed. Such work can be performed by some workshops and service stations that have the necessary equipment for this. If defects are found, they must be eliminated, if possible, or the unit replaced.
3. Examine the inner surfaces of the cylinders for scratches and burrs.
4. Measure the taper and ovality of the cylinders as follows (pic. 16.4, a-c).
5. Measure the diameter of each cylinder at the top (under the protruding collar), in the middle and at the bottom of the piston stroke in a direction parallel to the longitudinal axis of the engine. Then repeat measurements at the same levels perpendicular to the motor axis.
6. The taper of each cylinder can be found as the difference between the diameters at the top and bottom of the cylinder. The eplipse is the difference between the diameter measurements along and across the motor axis at the same level. Compare! e received values from technical data.
7. If Fable! a special tool for measuring the gaps between pistons and cylinders, then these gaps can be measured using ordinary flat probes, although with less accuracy. Select a feeler gauge of the correct thickness and insert it into the cylinder along with the corresponding piston. The piston should be located in the cylinder in the same way as in normal operation. The probe must be inserted along one of the sides of the cylinder, located at right angles to the longitudinal axis of the engine.
8. The piston, together with the feeler gauge, should move along the cylinder with some even friction.
9. If the piston easily falls into the cylinder, then the gap is large and the piston needs to be replaced. If the piston easily passes the reconciliation, but gets stuck at the bottom, then the cylinder has a taper. If, when turning the piston in the cylinder, a variable resistance is felt, then the cylinder has an ellipse.
10. Check up in the same way other cylinders.
11. If the cylinder bores are deeply scratched or burred, or if their taper or lipiness exceeds acceptable limits, send the cylinder bore and honing block to a workshop. After boring the cylinders, pistons and rings of repair sizes should be used.
12. Using a steel ruler, placed on edge, and probes, check the flatness of the mating surface of the block with the cylinder head (pic. 16.12). If the non-flatness exceeds the allowable level, the surface can be corrected by machining on the machine.
13. If the cylinder mirrors are in good condition, and their dimensions are within tolerances, then cylinder boring is not required, it is enough to do with honing (see paragraph 17).
14. The design of all engines described in this manual (both in-line and V-shaped), piston cooling is provided. For this, special oil nozzles are installed in the cylinders. On a V-shaped engine, they are located at the bases of the main bearings in the upper block. They can be unscrewed and screwed in with a screwdriver. Unscrew, clean these nozzles and screw them into place with a threaded seal. On a 4-cylinder in-line engine, the nozzles are installed at the bottom in the cylinder bores. Their nozzles are directed to the inner surface of the piston crown. To remove and install these nozzles, you need a special proprietary tool.
15. On the upper surfaces of both blocks of the V-shaped engine there are control plugs of the lubrication system (one for each block). The plugs can be pulled out with a self-tightening wrench and then new ones can be installed by replacing the O-rings underneath. Hammer new plugs into place with a mallet. The plugs should be replaced only after the unit has been externally cleaned to prevent dirt from entering the oil system.
Note. Hammer the plugs so that they protrude 13-14 mm above the surface of the block.