First, the ring end gaps must be examined prior to fitting new
Piston rings, though it can be assumed that if the manufacturer has got the side clearance of piston rings correct, so should the end gaps. Align the piston/connecting rod assemblies and the new ring sets so that they are corresponding with the piston and cylinder during the measurement and the engine build. Push the top ring into it while using the top of the piston to align it to the cylinder wall, place the ring at the lowest part of the cylinder. The slip feeler gauges should be inserted between the two ends of the ring and one with the thickness similar to the gap width should be used with a little dragging force. If the gap is not large enough it must be Increasing cautiously with a file starting from the outside of the ring ends in ; any burrs that have been produced must be filed off with a whetstone. End gap is not a major concern if it's more than the specified measurement, however the End GAP must be more than .040 inch, therefore, specific attention must be paid to identification of correct rings for the engine especially if the block has been bored oversize. Go through the same process for all the rings in all the cylinders ensuring that the rings, pistons, and cylinders are corresponding. After the check of the ring end gaps, the rings should be installed on the pistons: the oil control ring is one or three-piece. If the three-piece oil rings are utilized, the spacer/expander must be fitted into the groove, and the lower side rail has to be fitted into its place without the help of the piston ring installation tool because it might cause the rings to be deformed. Following the fitting of the three oil ring parts, you should be able to rotate both side rails in the grooved part. Next, place the middle ring in such the manner that the upper side of the mark is up, and insert the piston ring installation tool and squeeze the ring into the middle groove. Next, fit top ring in the same way making sure that the mark is on the top side and apply the same process on all the pistons and rings.