855456 Mercruiser GASKET-ROCKER COVER

Illustration 1 g00295602
Typical example (1) Diameter of the parent bore for the bushing in the connecting rod ... 32.930 to 32.955 mm (1.2965 to 1.2974 inch) (2) Bushing for the piston pin Inside diameter of the bushing for the piston pin after reaming ... 30.012 to 30.025 mm (1.1816 to 1.1821 inch) Outside diameter of the piston pin ... 29.995 to 30.000 mm (1.1809 to 1.1811 inch) Clearance between small end bushing and piston pin ... 0.003 to 0.014 mm (0.0001 to 0.0006 inch) (3) Distance between the center of the piston pin and the center of the crankshaft bearing ... 159.975 to 160.025 mm (6.2982 to 6.3002 inch) (4) Bearing for the connecting rod journal Thickness at center of bearing ... 1.500 to 1.506 mm (0.0591 to 0.0593 inch) Width of connecting rod bearing ... 22.87 to 23.13 mm (0.901 to 0.911 inch) Bearing clearance ... 0.018 to 0.064 mm (0.0007 to 0.0025 inch) (5) Inside diameter of the connecting rod ... 56.000 to 56.015 mm (2.2047 to 2.2053 inch) (6) Nut for the connecting rod cap Tighten the nuts for the connecting rod to the following torque. ... 54 N m (40 lb ft)
Illustration 2 g00777148
Fracture split connecting rod (7) Fracture split connecting rod Tighten the connecting rod bolts to the following torque. ... 47.5 N m (35 lb ft) Make a mark on the connecting rod bolts and the connecting rod. Additionally tighten the connecting rod bolts to the following value. ... 90 degreesNote: Do not mix fracture split connecting rods with any other type of connecting rods. Always use a complete set of four fracture split connecting rods.Note: The connecting rod bolts that are used with fracture split connecting rods may only be used once. Replace the connecting rod bolts whenever the connecting rods are removed.Note: When the connecting rod cap is removed for the first time, a small amount of metal may fall from the bolt holes in the connecting rod cap. Make sure that no metal particles fall into the engine when the connecting rod caps are removed.Markings on the Connecting Rod
The pistons and connecting rods are matched to each cylinder. Note the position of each connecting rod and piston for correct assembly.
Illustration 3 g00387456
(1) The cylinder number is etched in the left side of the connecting rod and the cap. (2) The letter that indicates the length grade of the connecting rod is etched below the marking for the cylinder number. (3) The letter which is etched on the right side of the connecting rod is the manufacturer's reference.The part number on the connecting rod should always be toward the front of the engine.Length Grades of a Connecting Rod
The length grade of a connecting rod is determined in the factory by machining an eccentric hole in a semi-finished piston pin bearing.If a connecting rod is replaced, a new connecting rod assembly must be purchased and installed. The new connecting rod will have a length grade of "B", "D", or "F" . The new assembly has a piston pin bearing which is installed in the new connecting rod. The piston pin bearing is reamed to the correct bore.For additional information on the connecting rods, refer to Testing and Adjusting, "Connecting Rod - Inspect".The length grades are shown in the following table:
Table 1
Original Grade     Grade for Replacement     Length    
"A" and "B"     "B"    
132.05 to 132.08 mm (5.199 to 5.200 inch)    
"C" and "D"     "D"    
131.99 to 132.02 mm (5.196 to 5.197 inch)    
"E" and "F"     "F"    
131.93 to 131.96 mm (5.194 to 5.195 inch)