TM 5-3895-382-24 Illustration 46 Piston and rings NOTE: The word "Front" or an arrow which is marked on the piston crown must be toward the front of the engine.  If the piston crown is not marked, put the narrowest  side  of  the  piston  crater  toward  the side  of  the  engine  with  the  fuel  injection  pump. The  shortest  distance  between  the  edge  of  the piston  crater  and  the  edge  of  the  piston  is  the narrowest side of the piston crater. NOTE: Be  sure  that  the  ring  end  gaps  of  all  the  piston rings have 120 degrees spacing from each other. NOTE: Refer to Systems Operation, "General Information" for the location of the serial number. Naturally Aspirated Engines (1) Width of groove in piston for top ring............................................................... 2.57 to 2.59 mm (.101 to .102 inch) Thickness of top ring ........................................... 2.48 to 2.49 mm (.097 to .098 inch) Clearance between groove and piston ring........................................................................... 0.08 to 0.11 mm (.003 to .004 inch) Clearance between the ends of the top ring with a cylinder liner without any wear  .................................................. 0.40 to 0.85 mm (.016 to .033 inch) (2) Width of groove in piston for intermediate ring .............................2.55 to 2.57 mm (.100 to .101 inch) Thickness of intermediate ring............................ 2.48 to 2.49 mm (.097 to .098 inch) Clearance between groove and intermediate ring........................................................................... 0.06 to 0.09 mm (.002 to .003 inch) Clearance    between    the    ends    of    the    intermediate    ring with a cylinder liner without any wear  ............... 0.30 to 0.76 mm (.012 to .030 inch) (3) Width of groove in piston for oil control ring ..........................................................4.030 to 4.060 mm (.1587 to .1598 inch) Thickness of oil control ring ............................3.980 to 3.990 mm (.1566 to .1571 inch) Clearance between groove and oil control ring........................................................................... 0.04 to 0.08 mm (.002 to .003 inch) Clearance between the ends of oil control ring with a cylinder liner without any wear ........................... 0.38 to 0.84 mm (.015 to .033 inch) (4) Diameter of new piston pin .............34.920 to 34.925 mm (1.3748 to 1.3750 inch) Bore in piston for pin ....................................34.928 to 34.934 mm (1.3751 to 1.3754 inch) Piston height above cylinder block (not shown)  ........................................................... 0.14 to 0.36 mm (.005 to .014 inch) Turbocharged Engines (1) Shape of groove in piston for top ring ......................Taper Shape of top ring .....................................................................Taper Clearance  between  the  ends  of  top  ring  in  a  cylinder  liner without any wear  .................................................. 0.35 to 0.75 mm (.014 to .030 inch) (2) Width of groove in piston for intermediate ring .............................................................. 2.56 to 2.58 mm (.101 to .102 inch) Thickness of intermediate ring ........................... 2.48 to 2.49 mm (.097 to .098 inch) Clearance between groove and intermediate ring........................................................................... 0.07 to 0.11 mm (.003 to .004 inch) Clearance between the ends of an intermediate ring in a cylinder liner without any wear ........................................................................ 0.30 to 0.76 mm (.012 to .030 inch) (3) Width of groove in piston for oil control ring ..........................................................4.040 to 4.060 mm (.1591 to .1598 inch) Thickness of oil control ring ................................ 3.98 to 3.99 mm (.156 to .157 inch) Clearance between groove and oil control ring........................................................................... 0.05 to 0.08 mm (.002 to .003 inch) 5-34