Geely JL481Q, Руководство пользователя

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Fig. 54 Check the Opening Clearance of Piston Ring
Fig.51 Position to Measure the Cylinder Diameter
Fig. 52 Mount the Pistons with the Same Numbers
as the Group Marks on Cylinder Block top side
Fig. 53 How to Locate the Piston Ring When Checking
the Opening Clearance of Piston Ring
NO.1,2or3
NO.1,2or3
Front-end mark
(concave cavity)
97mm
a. Measure the piston diameter vertical to the central line of piston
pinhole at 18mm away from the piston bottom side with micrometer
(Fig. 51). The standard piston diameter refers to table 4.
Extra dimension 0.5 (type): 79.115 to 79.145mm
b. Measure the inside diameter of cylinder bore in the thrust direc-
tion (Fig. 46).
c. Calculate the oil film clearance between the cylinder and the
piston by subtracting the measured piston diameter from the
measured inside diameter of cylinder bore.
d. If the oil film clearance is greater than the maximal value, replace
all the 4 pistons, and re-bore the 4 cylinders.
e. Replace the cylinder block if necessary.
f. In the case of using the new cylinder block, make sure to use the
pistons that have the same number marks as the dimension group
marks printed on the cylinder block topside (Fig. 52). In this way to
match the servicing dimension specification, the oil film clearance
may comply with the standard: 0.075 to 0.095mm. It’s stipulated that
the maximal oil film clearance is 0.115mm.
(2) .Check the clearance of piston ring opening to obtain the servic-
ing data reference
a. Press the piston ring into the cylinder hole.
b. Use the piston as the tool, with the piston top downwards, to push
the piston ring to the bottom part that is 97mm away from the
cylinder block topside, just exceeding the ring distance (Fig. 53).
c. Measure the opening clearance with the thickness feler (Fig. 54).
Standard opening clearance:
Ring1: 0.20 to 0.40mm;
28.5mm
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