How to Install Piston Rings

This guide covers a piston ring set with two compression rings and a three-piece oil control ring. Before fitting the rings, clean the piston grooves and oil return holes. Check each ring’s end gap in the cylinder bore and its side clearance in the matching groove against the engine specifications.

1 Install the three-piece oil control ring

Start with the lowest groove. Fit the expander first and make sure its ends meet without overlapping. Fit the lower steel rail, then the upper rail. Check that both rails are seated and that the assembly moves freely in the groove.

2 Install the second and top compression rings

Use piston ring pliers to fit the second ring in the middle groove, then fit the top ring in the upper groove. Open each ring only enough to clear the piston. If the ring carries a TOP mark or another orientation mark specified by its manufacturer, face the marked side toward the piston crown.

3 Set the ring gap positions

Follow the gap layout specified for the engine and ring set. Check the positions of both compression ring gaps, both oil rail gaps and the expander joint before using a ring compressor to insert the piston into the cylinder.

To match a replacement piston ring set, send CTPR the engine model, OE part number or a clear photo of the original rings.