Before installing the new 
Piston rings, the ring end gaps must be checked, assuming that the piston ring side clearance has been verified correct. Lay out the piston/connecting rod assemblies and the new ring sets to match them with the same piston and cylinder during the end gap measurement and engine assembly. Insert the top ring into the first cylinder, ensuring it is square with the cylinder walls by pushing it in with the top of the piston, positioning the ring near the bottom of the cylinder at the lower limit of ring travel. To measure the ring end gap, slip feeler gauges between the ends of the ring until a gauge equal to the gap width is found, ensuring the feeler gauge slides between the ring ends with slight drag. Compare the measurement to the specified ring end gap; if it is not within specification, replace the ring without filing it. Repeat this procedure for all three rings on each piston, keeping rings, pistons, and cylinders matched. Once the ring end gaps have been checked and corrected, install the rings on the pistons, starting with the oil control ring, which consists of three components: first, slip the spacer/expander into the groove, then install the lower side rail without using a piston ring installation tool to avoid damage, and finally, install the upper side rail in the same manner. After installing the oil ring components, ensure that both the upper and lower side rails can turn smoothly in the ring groove. Next, install the No. 2 (middle) compression ring, ensuring the stamped mark faces up toward the top of the piston, and follow the instructions printed on the ring package, avoiding mixing up the top and middle rings due to their different cross sections. Use a piston ring installation tool to ensure the identification mark is facing the top of the piston while slipping the ring into the middle groove, taking care not to expand the ring more than necessary. Install the No. 1 (top) compression ring in the same manner, ensuring the mark is facing up, and be cautious not to confuse the No. 1 and No. 2 rings. Repeat this procedure for the remaining pistons and rings.