Piston: Service and Repair

Fig. 5 Liner tab positioning:

Fig. 6 Depressing cylinder liners:

Pistons and liners are available only as matched sets. Pistons may be removed from connecting rods by removing piston pin circlips and piston pins. Assemble piston and connecting rod so arrow and AV mark point forward and oil thrower hole on connecting rod is facing away from camshaft. If necessary, heat pistons in boiling water to ease piston pin installation. Install oil scraper with gaps .79-1.97 inch (20-50 mm) from center of piston pin hole. Install remaining rings with gaps about 120° from pin center line. Marks on piston ring must face top of piston.

When installing piston and liner assemblies, do not mix assemblies and make sure there are no burr marks on face of engine block. Insert liners without pistons and base gaskets into block with flats on liners 1-2 and 3-4 facing. Using dial indicator, measure protrusion above block face at four points on each liner. Maximum difference between two diametrically opposed points cannot exceed 0.003 inch (0.07 mm). A base gasket must be selected for each liner which will give a protrusion (including gasket) of 0.003-0.006 inch (0.07-0.14 mm) at the highest point, with the preferred setting as close as possible to 0.006 inch. Gaskets are available in four thicknesses as indicated by notches in reference tab: no notch, 0.0028-0.0041 inch (0.070-0.105 mm); one notch, 0.0033-0.0047 inch (0.085-0.120 mm); two notches, 0.0041-0.0055 inch (0.105-0.140 mm); three notches, 0.0051-0.0065 inch (0.130-0.165 mm). Place selected gasket on liner and engage the inner tabs in the grooves. Install liners in engine block with tabs positioned as shown in Fig. 5. Using tool 8.0128, Fig. 6, press liners down. Check protrusion at (A), (B), (C) and (D), Fig. 6. Protrusion should not exceed 0.006 inch (0.14 mm) and the difference between the four checking points must not exceed 0.003 inch (0.07 mm). The difference in protrusion height of the liner must not exceed 0.0016 inch (0.04 mm).