Genuine Mazda 626 Piston Ring

Mazda 626 Piston Ring Parts and Q&A

• Piston Ring Set
  F2Y1-11-SC0
  Q: How should the end gaps of piston rings be checked and corrected before installation on Mazda 626?

  A:

  The ring end clearance should be inspected before the new Piston rings are installed, assuming that the clearance at the piston ring has been determined to be correct. Prepare the piston/ connecting rod assemblies and new ring sets by aligning the new ring sets to the same piston/ cylinder as the ring sets during the end gap check and engine assembly. Plug the upper ring in the first cylinder, and align it with the walls of the cylinder, by pressing it in on the top of the piston, so that the ring is guided in the bottom part of the cylinder at the low limit of ring travel. In order to test the end gap, insert a feeler gauge between the ends of the ring and compare the result with the specification. In case the gap is bigger or smaller than stated, recheck in order to be precise that the correct rings are being used. When the gap is too narrow, it should be widened to avoid contacting of the ends of the rings when the engine is running and severe damage may result. An increase of end gap may be done by filing off the ends of the rings by using a fine file, but again only on the outside only, as excess end gap is not critical until it reaches 0.040-inch (1 mm), and it is essential to check the rings against the engine. Repeat the steps with each ring in the first cylinder and the second, third, and fourth cylinders where the rings, pistons and cylinders should be identical. When the gaps on the ends of the rings are verified and fixed, the rings are then attached to the pistons with the oil control ring being the first to be installed and this ring is made of three parts. Install the lower side rail without the use of a piston ring installation tool, slide the spacer/expander into the groove and install. Rather stick one end of the side rail into the groove and roll a finger around the piston as the rail is pushed into the groove and then install the upper side rail in the same way. Once the three oil ring parts are installed, ensure that the upper and lower side rails will rotate freely in the ring groove. Then install the middle ring that has an R mark facing the top of the piston, and should not be confused with the top ring, which has a different cross section. Installation is installed with a piston ring tool by sliding the middle ring at the groove with the identification mark on the top and then the top ring is installed with the same tool and should not be mixed with the other ring.