2. Lay out the pistons and connecting rods and new track sets so that the groups of parts are together during and after checking the joint clearances. Lay the cylinder block on its side to allow access to the cylinders from both above and below.
3. Take the top compression ring of piston #1 and insert it into the first cylinder from above. Push it down with the piston crown - this will ensure that the ring is perpendicular to the cylinder walls. Position the ring at the bottom of the cylinder, approximately where it would be when the piston is at bottom dead center. Remember that the top and second compression rings are different. The second compression ring is easily distinguished by the presence of a step on the bottom surface.
4. Measure the thermal gap in the ring lock with a feeler gauge.
5. Repeat the measurement in the upper position of the ring (see fig. 18.5). Compare the measurement results with the values in the "Technical data" section. If the data is not provided, consult a specialist.
Fig. 18.5. Determining the gap in the ring lock
6. When installing new rings, avoid too small a gap in the lock, otherwise, if the ends of the ring touch during operation, there is a risk of damaging the cylinder mirror. Ideally, you should select a ring so that the gap in its lock is equal to the nominal one, but in extreme cases this problem can be solved by filing the ends of the ring with a thin file. Fix the file in a vice, spread the ring over the file and slowly move the ring to remove material from its ends. Be careful - the rings are fragile and have sharp edges.
7. It is also undesirable for the gap in the lock to be too large. If the gap is large, check whether the ring matches the size of the cylinders of your engine.
8. Continue the inspection procedure for all rings of the first cylinder, then the next, etc. Do not forget to mark the pistons and rings matched to the cylinders.
9. After the clearances in the locks have been checked and, if necessary, adjusted, the rings can be installed in the pistons.
10. Install the rings using the same technique as when removing them. First install the lower oil scraper ring. When installing the ring, insert the expander, then install the oil scraper ring so that the gap is at an angle of 180° to the gap on the expander. Find the marking on one side of the second compression ring (either painted or stamped "TOP") and install the ring with this side up and the bevel down (see Fig. 18.10, a, b). After installing all the rings, rotate their locks at an angle of 120° to each other. Make sure that none of the ring locks are located above the piston pin hole.
Note: Always follow the instructions that come with your new rings - different manufacturers may have different procedures. Don't be alarmed by the first and second compression rings - they have different cross-sections.
Fig. 18.10, a. Installing the oil scraper ring expander
Fig. 18.10, b. Typical arrangement of rings.
1 Oil scraper ring
2 Second compression ring
3 Upper compression ring