9Y6771 And 121-4695 Piston Group (Three Ring Piston)
(1) Connecting rod. Connecting rods and caps to be marked (by etching only) with the number of the cylinder in which they are used. Connecting rods and caps are to be marked with numbers one through eight on this side of connecting rod in relation to the connecting rod bearing retainer notch.
View A-A
(2) Piston crater.
NOTE: Assemble piston and connecting rod with piston crater (2) and connecting rod orientation (1) as shown. Connecting rod and piston group to be installed in engine with piston crater (2) directed toward the engine centerline (both banks).
Top And Intermediate Piston Ring
Top Piston Ring
(3) Top piston ring. Install top piston ring (3) with “UP-1” and “CAT” on the top side of the ring.
Clearance between ends of top piston rings when installed in a cylinder:
9Y6774 Top Ring-Standard size bore (new) 114.300 mm (4.5000 in) … 0.572 ± 0.190 mm (.0225 ± .0075 in)
121-4696 Top Ring-Standard size bore (new) 114.300 mm (4.5000 in) … 0.570 ± 0.19 mm (.0224 ± .0075 in)
121-4697 Top Ring-Standard size bore (new) 114.300 mm (4.5000 in) … 0.525 ± 0.125 mm (.0207 ± .0049 in)
Increase in clearance between ends of piston ring for each 0.03 mm (.001 in) increase in cylinder bore size … 0.08 mm (.003 in)
Intermediate Piston Ring
(4) Intermediate piston ring. Install the intermediate piston ring (4) with “UP-2” and “CAT” on the top side of the ring.
Clearance between ends of intermediate piston rings when installed in a cylinder:
9Y6775 And 123-9760 Intermediate Ring-Standard size bore (new) 114.300 mm (4.5000 in) … 0.572 ± 0.190 mm (.0225 ± .0075 in)
123-9759 Intermediate Ring-Standard size bore (new) 114.300 mm (4.5000 in) … 0.780 ± 0.180 mm (.0307 ± .0071 in)
Increase in clearance between ends of piston ring for each 0.03 mm (.001 in) increase in cylinder bore size … 0.08 mm (.003 in)
Oil Control Ring
7E7246 And 6I3188 Oil Control Ring
(5) Oil control ring. Install oil control ring (5) with the gap in the spring 180 ± 45 degrees away from the gap in the ring.
Width of groove in piston for piston ring (new) … 2.806 ± 0.013 mm (.1105 ± .0005 in)
Thickness of piston ring (new) … 2.756 ± 0.013 mm (.1085 ± .0005 in)
Clearance between piston groove and piston ring … .024 to .076 mm (.0009 to .0030 in)
Clearance between ends of piston ring when installed in the cylinder:
Standard size bore (new) 114.300 mm (4.5000 in) … 0.505 ± 0.255 mm (.0199 ± .0100 in)
Increase in clearance between ends of piston ring for each 0.03 mm (.001 in) increase in cylinder bore size … 0.08 mm (.003 in)
After rings have been installed, rotate rings to that the end gaps are 120 degrees apart.
123-8628 Oil Control Ring
(5) Oil control ring. Install oil control ring (5) with the gap in the spring 180 ± 45 degrees away from the gap in the ring.
Width of groove in piston for piston ring (new) … 4.033 ± 0.013 mm (.1588 ± .0005 in)
Thickness of piston ring (new) … 3.982 ± 0.008 mm (.1568 ± .0003 in)
Clearance between piston groove and piston ring … 0.030 to 0.072 mm (.0012 to .0028 in)
Clearance between ends of piston ring when installed in the cylinder:
Standard size bore (new) 114.300 mm (4.5000 in) … 0.508 ± 0.127 mm (.0200 ± .0050 in)
Increase in clearance between ends of piston ring for each 0.03 mm (.001 in) increase in cylinder bore size … 0.08 mm (.003 in)
After rings have been installed, rotate rings to that the end gaps are 120 degrees apart.
123-8629 Oil Control Ring
(5) Oil control ring. Install oil control ring (5) with the gap in the spring 180 ± 45 degrees away from the gap in the ring.
Width of groove in piston for piston ring (new) … 4.033 ± 0.013 mm (.1588 ± .0005 in)
Thickness of piston ring (new) … 3.970 ± 0.010 mm (.1563 ± .0004 in)
Clearance between piston groove and piston ring … 0.040 to 0.086 mm (.0016 to .0034 in)
Clearance between ends of piston ring when installed in the cylinder:
Standard size bore (new) 114.300 mm (4.5000 in) … 0.505 ± 0.255 mm (.0199 ± .0100 in)
Increase in clearance between ends of piston ring for each 0.03 mm (.001 in) increase in cylinder bore size … 0.08 mm (.003 in)
After rings have been installed, rotate rings to that the end gaps are 120 degrees apart.
Piston Pin Bore
(6) Piston pin bore. The piston pin bore diameter is … 38.123 to 38.133 mm (1.5009 to 1.5013 in)
Maximum piston pin bore diameter … 38.158 mm (1.50228 in)
Pin diameter … 38.092 to 38.102 mm (1.4997 to 1.5001 in)
Clearance between pin and bore in piston (new) … 0.021 to 0.041 mm (.0008 to .0016 in)
Maximum permissible clearance between piston pin and bore in piston (worn) … 0.066 mm (.0026 in)
9N6435 Piston Group (Two Ring Piston)
(1) Connecting rod. Connecting rods and caps to be marked (by etching only) with the number of the cylinder in which they are used. Connecting rods and caps are to be marked with numbers one through eight on this side of connecting rod in relation to the connecting rod bearing retainer notch.
View A-A
(2) Piston crater.
NOTE: Assemble piston and connecting rod with piston crater (2) and connecting rod orientation (1) as shown. Connecting rod and piston group to be installed in engine with piston crater (2) directed toward the engine centerline (both banks).
Top Piston Ring
NOTE: Use 5P3519 Piston Ring Groove Gauge to check the ring grooves. For instructions on the use of the gauge, see the Guidelines For Reusable Parts; Pistons, SEBF8049.
(3) Top piston ring. Install top piston ring (3) with “UP-1” an “CAT” on the top side of the ring.
Width of groove in piston for piston ring (new) … 3.276 ± 0.013 mm (.1290 ± .0005 in)
Thickness of 9L6233 Piston Ring (new) … 3.112 to 3.150 mm (.1225 to .1240 in)
Clearance between piston groove and piston ring … 0.113 to 0.177 mm (.0044 to .0070 in)
Clearance between ends of top ring when installed in a cylinder:
Standard size bore (new) 114.300 mm (4.5000 in) … 0.572 ± 0.190 mm (.0225 ± .0074803 in)
Increase in clearance between ends of piston ring for each 0.03 mm (.001 in) increase in cylinder bore size … 0.08 mm (.003 in)
Oil Control Ring
7E7246 And 6I3188 Oil Control Rings
(4) Oil control ring. Install oil control ring (5) with the gap in the spring 180 ± 45 degrees away from the gap in the ring.
Width of groove in piston for piston ring (new) … 2.806 ± 0.013 mm (.1105 ± .0005 in)
Thickness of piston ring (new) … 2.756 ± 0.013 mm (.1085 ± .0005 in)
Clearance between piston groove and piston ring … .024 to .076 mm (.0009 to .0030 in)
Clearance between ends of piston ring when installed in the cylinder:
Standard size bore (new) 114.300 mm (4.5000 in) … 0.505 ± 0.255 mm (.0199 ± .0100 in)
Increase in clearance between ends of piston ring for each 0.03 mm (.001 in) increase in cylinder bore size … 0.08 mm (.003 in)
After rings have been installed, rotate rings to that the end gaps are 120 degrees apart.
Piston Pin Bore
(5) Piston pin bore. The piston pin bore diameter is … 38.123 to 38.133 mm (1.5009 to 1.5013 in)
Maximum pin bore diameter … 38.158 mm (1.50228 in)
Pin diameter … 38.092 to 38.102 mm (1.4997 to 1.5001 in)
Clearance between pin and bore in piston (new) … 0.021 to 0.041 mm (.0008 to .0016 in)
Maximum permissible clearance between piston pin and bore in piston (worn) … 0.066 mm (.0026 in)