Installing piston rings (Skoda Felicia)

1. Make sure that the pistons are seated correctly on their connecting rods and the piston rings are in their grooves (see section Removal, condition check and installation of connecting rod and piston assemblies).

2. Before installing the rings on the pistons, it is necessary to check the size of the gaps in their locks.

3. Lay the piston assemblies and their ring sets on a clean work surface. Lay the cylinder block on its side on the workbench, ensuring access to both its top and bottom.

4. Insert the upper compression ring of the corresponding piston into the first cylinder of the engine. Use the bottom of the piston to push the ring into the lower part of the cylinder. Remove the piston.

5. Using a blade type feeler gauge, measure the gap in the ring lock - the blade is of the required thickness (see Specifications) should slide tightly between the end surfaces of the ring in its lock. Before rejecting the ring, make sure that you have not confused it with the lower one. Repeat the procedure for the remaining rings.

6. When using brand new piston rings, the probability that the gaps in their locks will be too small is extremely small - remember that closing the locks during thermal expansion of the rings is fraught with engine jamming and irreversible failure. If necessary, the gap should be adjusted by gradually grinding the ends of the ring on a file clamped in a vice - tightly put the ring with the lock on the file and pull it towards you (under no circumstances away from yourself to avoid the risk of breaking the ring when closing the lock). If the measurement result exceeds the permissible value (which is highly unlikely in the case of new rings), before you reject a ring, make sure you have purchased a set of rings that match the engine size of your vehicle.

7. After completing the check and adjustment of the gaps in the locks of all the rings, you can begin to put them on their pistons. The technology for putting the rings on the piston is similar to that used for their removal. First of all, the spring expander of the lower part is inserted into its groove on the piston (oil scraper) rings, then both of its side sections are installed. Note that both the expander and the side sections of the oil scraper ring can be installed with either side up. The second and upper compression rings have different cross-sections and can be distinguished from each other by the markings applied to their upper sides. Make sure that the rings are installed on the piston with the markings facing up.

8. After finishing installing the rings on the piston, check that they rotate freely in their grooves, then turn the locks at 120° to each other.