Doosan G20P-5, Руководство по обслуживанию

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G424F(FE) Service Manual Chapter 3. Engine Mechanical System 90
54.
Engine assembly; see “Engine Assembly –
Installation”, in this section.
Cylinder Block
Removal
Remove or disconnect
1.
Disassemble the engine as per instructions under
“Engine Disassembly”, in this section.
2.
Water and oil gallery bolts, with a 7-mm Allen
wrench and handle.
3.
Cylinder block seals.
Clean
•
Cylinder block, thoroughly.
Inspect
•
Cylinder block for cracks and wear.
Cylinder Reconditioning
If the cylinder block inspection discloses that only
the cylinder are out of roundness and that the
cylinder block may be reused, the cylinders can be
reconditioned by honing or by grinding or honing or
reboring.
If the wear or out-of-roundness is over 0.127 mm
(0.005 in.), the cylinders should be rebored and
honed until it is possible to install an oversize piston
after the reconditioning is finished.
Cylinder Honing
Note:
Some of the services that are next presented
are not necessarily performed when reconditioning
an engine.
The performance should depend on the inspections
to which the engines will be submitted before
reconditioning.
The finish after reboring should be made with a
cylinder hone. The initial honing should be
performed with thick stones and finish with thin
stones. It should not remain glistened, but with light
strokes, so as to help the lubrication.
Install the cylinder hone and lean the stones the
maximum as possible, so that the hone does not
remain blocked from being manually turned.
Connect a 19 mm (3/4 in.) electric driller to the hone,
make it rotate and, at the same time, slowly actuate
the hone upward and downward, all along the
cylinder length, until it freely turns.
When honing, insert into the cylinder a good amount
of kerosene, so as to keep the stones and cylinders
clean and lubricated.
Expand the hone stones and repeat the honing until
obtaining the required diameter.
Note:
Stop once in a while the honing and insert the
piston into the corresponding cylinder, so as to
check the play. Before inserting the piston,
thoroughly clean the cylinder.
After servicing the block, clean it thoroughly.
Install or connect
1.
Water and oil gallery bolts, with a 7-mm Allen
wrench and torque wrench; tighten.
Tighten
•
Bolts: 25 – 35 N
·
m (18 – 25,7 lb
·
ft.).
2.
Cylinder block seals, with tool 3-0006774 and
universal handle M-740463A.
3.
Assemble the engine, as per instructions under
“Engine Assembly”, in this section.