Pistol Ring Installation

• After the old piston rings are removed, thoroughly remove all carbon. Check the dowel pin, if piston is so equipped, to be sure it is not loose or worn. Clean oil groove drain holes and carefully inspect for cracks and other defects.
• Check compression ring lands for wear, especially the top groove. Wear (taper, step, etc.) should not exceed engine builder condemnation limits, highly loaded engines should have little or no groove wear.
• If cylinders have been honed, wash cylinder with soap and warm water using a stiff brush. Solvents will not do the job.
• Groove depth must be slightly greater than radial thickness of the ring. This can be checked with a straight edge placed against the piston after the ring is slipped into the groove.
• Unless ample end clearance is allowed, rings may get damaged from expansion, causing cylinder scoring and other serious trouble. If there is insufficient end clearance, the ring ends should be filed down.
• Check the rings for burred edges that occasionally develop from rough handling. Burrs should be carefully removed before the rings are used.
• Before being installed on the piston, each ring should be rolled around in the piston groove where it is to be used to make sure it does not bind at any point.
• Check ring side clearances against builder specifications. In some cases the ring manufacturer may use less side clearance than the engine builder specifications call for, due to the ring material and ring combination being used. In all cases the ring must be free in its groove and should not bind against the groove sides. A wavy ring will show correct clearance, but will be tight in the groove.
• Check each new ring in the unworn part of the cylinder to determine if there is sufficient clearance. Use engine builder standards. If engine builder standards are not known, check with your ring supplier. Should it be necessary to file the ring ends to provide adequate end gap, lay the ring flat a on table with ends extending over the edge. Clamp the ring with a piece of soft wood across the end to be filed. File as flat as possible.
• Check the Engineered Ring Set Bulletin provided in each set package, to determine which ring goes in a particular groove. Be sure sealing rings and other rings with directional requirements (Taper Face, etc.) are installed with word "Top" toward the pressure side of the piston. Check each ring for damage, nicks, burrs, etc. Do not install chrome-faced rings on pistons to be used in chrome cylinders.
• Carefully spread each ring over the piston and install in correct groove. Start with the lower ring first to prevent passing over a previously installed ring. For spring tensioned oil rings, oil and install the spring first, then carefully install the ring over the spring with the spring joint opposite the ring joint. Compression rings should have their joints staggered if not pinned.
• Check the ring wall thickness to the groove depth by establishing that the ring will fit completely recessed into the groove, without extending past the piston surface. If any ring will not recess into its correct groove (including oil rings), check: (A) to be sure the ring is in the correct groove (B) to see if the groove is clean and free from carbon (C) wall thickness to groove depth.
• With all rings installed in their proper groove, oil the rings, piston, and cylinder liberally with clean light-weight oil (engine weight O.K.). Install the piston into the cylinder through a well-oiled entering sleeve of correct size. Proceed slowly to determine that the piston slips freely and easily into the cylinder. Do not force. Check rings if entry is not free and easy.