49108 Mercruiser STUD, OIL PUMP TO CYLINDER BLOCK

Illustration 1 g06180807
Table 1
Specification for 423-7798 Piston
Item Qty Part Specification Description
Thoroughly lubricate the ring grooves of the entire piston with the clean engine oil before installation of the piston rings. After assembly, completely lubricate the mating surfaces of the rings to the cylinder liner with the clean engine oil.
1 1 7E-7581 Piston Ring Install the piston ring with the "UP-1" side toward the top of the piston. The top piston ring must be installed with the colored stripe to the right of the ring end gap.
Width of groove in new piston for the top piston ring is 3.600 0.010 mm (0.1417 0.0004 inch).
When the piston ring is installed in a cylinder liner with a bore size of 170 mm (6.7 inch), the clearance between the ends of the piston ring is 0.8 0.2 mm (0.03 0.01 inch).
Thickness of the new top piston ring is 3.45 to 3.49 mm (0.136 to 0.137 inch).
2 1 348-8779 Piston Ring Install the piston ring with the "UP-2" side toward the top of the piston. The intermediate piston ring must be installed with the colored stripe to the right of the ring end gap.
Width of groove in new piston for intermediate piston ring is 3.600 0.010 mm (0.1417 0.0004 inch).
When the piston ring is installed in a cylinder liner with a bore size of 170 mm (6.7 inch), the clearance between the ends of the piston ring is 1.700 0.150 mm (0.0669 0.0059 inch).
Thickness of the new intermediate piston ring is 3.470 0.020 mm (0.1366 0.0008 inch).
3 1 223-6361 Ring The spring ends of the oil control piston ring should be assembled 180 degrees from the ring end gap. The colored portion of the piston ring must be visible at the ring end gap.
Width of groove in piston for the new oil piston ring is 4.060 0.010 mm (0.1598 0.0004 inch).
When the piston ring is installed in a cylinder liner with a bore size of 170 mm (6.7 inch), the clearance between the ends of the piston ring is 0.5 to 0.8 mm (0.02 to 0.03 inch).
Thickness of new oil piston ring is 3.980 0.010 mm (0.1567 0.0004 inch).
After all piston rings have been installed, rotate the piston rings, so that the end gaps are 120 degrees from each other.
4 - - Bore diameter for piston pin is 70.38 0.10 mm (2.771 0.004 inch).
5 1 138-8506 Piston Pin Before assembly, completely lubricate the piston pin, the piston pin bore, the connecting rod eye, and the connecting rod pin bearing with clean engine oil.
Diameter is 69.962 0.005 mm (2.7544 0.0002 inch).
Length of piston pin is 137.60 0.13 mm (5.417 0.005 inch).
6 2 8N-7296 Pin Retainer Assemble the pin retainer with the gap towards the top of the piston.
Thickness of the new retainer ring is 2.40 0.08 mm (0.094 0.003 inch).
Width of groove in the new piston for the retainer ring is 2.75 0.15 mm (0.108 0.006 inch).