Should there be a manufacturers I.D. mark, make sure it is facing in the direction of the top of the
Piston. First, put in the rings one after another as follows: upper piston ring, intermediate piston ring, side rail with oil rings, lower side rail with oil rings and expander for the oil rings. Put one end of the side rail between the piston ring groove and the expander and press down gently on it, holding firmly until it is correctly positioned and remains that way without using the piston ring expander. Set the lower side rail first, then add the upper side rail and then add No. 2 piston ring followed by No. 1 piston ring. Oil should be able to fill the gaps between the piston rings and around the oil ring expander, while at least 45° should separate the expander gap from the side rail gaps, making it not preferable for the ring gaps to be near the piston pin or in the direction of thrust.