Maintenance Manual of 4M11 Series Diesel Engine For Land Power Generators
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tightening torque of connecting rod bolts.
2.
Tilt the engine, turn the piston to be disassembled to the bottom dead center, and
disassemble the connecting rod bolts and connecting rod cap.
3.
Turn to the top dead center, knock out the piston by a wood hammer, and operate with
caution to prevent the connecting rod large end from blocking the cylinder block.
4.
Disassemble the remaining pistons by the same method, and put them in sequence.
5.
Use a pair of internal circlip pliers to dismantle the circlips on both sides of the piston
carefully, and push out the piston pin to disassemble the connecting rod shank. Assign
numbers to the piston pin and connecting rod shank, and put them in numerical sequence.
6.
Use a pair of piston ring pliers to dismantle the 1st & 2nd gas rings and oil ring
respectively, and mark them.
4.4.2.3
Inspection and Maintenance of Piston Connecting Rod Group
1.
Check whether the combustion chamber throat fillet of piston and piston pin seat have
cracks; check whether the piston skirt and head have scuffing phenomenon; and check
whether the wearing of piston pin hole is normal;
2.
Check the outer surfaces of piston rings for excessive wear. Check the upper and lower
sides of piston rings for excessive wear.
3.
Check the outer surface of piston pin for excessive wear.
4.
Check the connecting rod big end pre-formed hole, connecting rod shank, and connecting
rod small end lubricating oil hole for cracks. Check the connecting rod bearing shells for
excessive wear or peeling-off of alloy layer. Check the flanks of connecting rod for
excessive wear. Check the connecting rod shank for bending.
5.
Check the connecting rod bearing shell for excessive wear, discoloration, peeling-off, and
sliding of alloy layer.
4.4.2.4
Piston Connecting Rod Group Assembly Procedures
1.
Use a pair of internal circlip pliers to assemble one circlip onto the piston circlip groove,
and turn the circlip to have it inserted completely. The rough side of the circlip should be
inward. The open end of the piston pin circlip should be upward.
2.
Insert the connecting rod small end into the inner cavity of the piston, and enable the small
end to align with the piston pin hole, and then mount the piston pin, and eventually mount
the piston pin circlip on other side. Note that the connecting rod oblique split plane in the
same direction as the piston cooling oil passage. Apply a proper amount of lubricating oil
to the connecting rod small end and piston before assembly.
3.
Put the assembled parts of the piston connecting rod aside in sequence of the cylinder
