Fitting Piston Rings

Piston rings are of two types - compression (plain face) and oil control ring. The two compression rings are positioned in the two upper piston ring grooves with the stamped word "TOP" or a dot (.) upward. Rings are regularly supplied in the following over-sizes to fit standard oversize pistons: .005, .010,

Figure 3C-5. Measuring Piston

Figure 3C-6. Measuring Ring Side Clearance

Compression rings must have proper side clearance in ring grooves. In new assembly this is .004 in. Check with thickness gauge as shown in Fig. 3C -6. Maximum side clearance is .008 in. Compression ring gap (space between ends) is .010 in. to .020 in.

U-Flex oil control rings should have 11/32 in. overlap when placed free in cylinder bore. Replace ring when worn to 7/32 in. or less overlap.

Figure 3C-7. Checking Ring Gap

Legend (install in order shown)

2. Expander Spring 5. Rail

3. Rail

Figure 3C-8. Rail Type Oil Ring Assembly MEMO

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