Routine Inspection - Chery QQ Service Manual

Chery QQ Service Manual

4 Routine Inspection

4.1 Cylinder Body
4.1.1 Inspect the top surface of cylinder body for its
flatness
(1) Measure at the six points shown in the right figure
with a ruler and a feeler gauge.
Limit: 0.08mm
4.1.2 Use of bore gauge
Measure the cylinder bore at the positions as indicated in
the right figure with a bore gauge, and figure out the
difference between the maximum value and the miximum
value. If the difference exceeds the limit, repair or replace
the cylinder.
Limit: 0.03mm
[Reference] Roundness: A-B or a-b
Cylindric degree: A-a or
[Reference] Standard
φ72.00-72.01mm
4.2 Piston
4.2.1 Inspect the piston pin hole for its clearance
Measure the piston pin at several positions with a
micrometer caliper shown in the figure, make the
maximum value as the diameter of pin.
4.2.2 Measure the diameter of piston pin at several
positions with an inner-diameter dial gauge as shown in the
figure, make the minimum value as the diameter of the pin
hole.
Work out the clearance with the difference between the
pin diameter and pin hole diameter, if the difference is
beyond the standard value, replace the piston pin or piston.
Standard value: 0.004-0.009mm
Limit: 0.015mm
diameter of cylinder:
Mechanical Part of SQR 472Engine
44
Upper Stopper Position of Piston
Lower Stopper Position of Piston
Measurement Position
Piston Pin
of