Ford 6L3Z-6148-A Piston Ring Set

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 it near the bottom of the cylinder. To measure the 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 specifications; if the gap is larger or smaller than specified, double-check the rings for correctness. Excess end gap isn't critical unless it exceeds 0.040-inch, so verify the correct rings for your engine. Repeat the procedure for each ring in the first cylinder and the remaining cylinders, 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. Slip the spacer/expander into the groove, followed by the lower side rail, ensuring not to use a piston ring installation tool to avoid damage. Install the upper side rail in the same manner and check that both side rails can turn smoothly in the ring groove. Next, install the middle ring, ensuring the stamped mark faces up, and use a piston ring installation tool to slide it into the middle groove. Finally, install the top ring in the same manner, ensuring the mark is facing up, and repeat the procedure for the remaining pistons and rings.