Chery Tiggo. Manual — part 70
1. Using the special tool MD-998772 (1), compress
the valve springs.
2. Remove the valve keeper, valve spring retainer
and valve spring.
3. Remove valves from the cylinder head.
Valves
• Clean all valves thoroughly and discard burned,
warped and cracked valves.
• Check valve seats and valve faces for damage.
• When reconditioning valves follow the specifications
outlined for both intake and exhaust valves.
• Measure valve deflection.
VALVE DEFLECTION LIMIT (DIAL GAUGE READING)
Intake Valve
0.02 mm
Exhaust Valve
0.04 mm
CYLINDER HEAD UNIT REPAIR
LTSM020092
BESM020066
• If it exceeds the limit, check valve to valve guide clearance (1) .
− Measure valve stem diameter (2) and valve guide inner diameter (3).
− Check that clearance is within specification.
− If it exceeds the limit, replace valve or valve
guide.
VALVE TO VALVE GUIDE CLEARANCE
DESCRIPTION
SPECIFICATION
LIMIT
Intake Valve Clearance
0.020 - 0.050 mm
0.10 mm
Exhaust Valve Clearance
0.030 - 0.070 mm
0.15 mm
• Check the valve edge thickness and valve contact
area. Repair or replace the valve if necessary.
VALVE EDGE THICKNESS
DESCRIPTION
SPECIFICATION
LIMIT
Intake Valve Edge Thickness
1.0 mm
0.5 mm
Exhaust Valve Edge Thickness
1.2 mm
0.7 mm
CYLINDER HEAD UNIT REPAIR
LTSM020101
BESM020066
02
• Measure the total valve height (1). If the valve
height is less than the limit value, the valve should
be replaced.
VALVE HEIGHT
DESCRIPTION
SPECIFICATION
LIMIT
Intake Valve Height
112.30 mm
111.80 mm
Exhaust Valve Height
114.11 mm
113.61 mm
Valve Guides
• Check the clearance (1) between the valve guide
and the valve stem, if it exceeds the limit, check
valve to valve guide clearance.
− Measure valve stem diameter (2) and valve
guide inner diameter (3).
− Check that clearance is within specification.
− If it exceeds the limit, replace valve or valve
guide.
VALVE TO VALVE GUIDE CLEARANCE
DESCRIPTION
SPECIFICATION
LIMIT
Intake Valve Clearance
0.020 - 0.050 mm
0.10 mm
Exhaust Valve Clearance
0.030 - 0.070 mm
0.15 mm
Valve Guide Replacement
• Press the original valve guide out of the cylinder head.
• Ream the valve guide hole until the hole diameter is the size of the new enlarged valve guide to be installed.
CAUTION:
When replacing valve guides, do not use a new valve guide that is the same size as the original
valve guide.
− Enlarge valve guide size 0.05 (11.05 - 11.068 mm)
− Enlarge valve guide size 0.25 (11.25 - 11.268 mm)
− Enlarge valve guide size 0.50 (11.50 - 11.518 mm)
CYLINDER HEAD UNIT REPAIR
LTSM020102
LTSM020101
• Install the new valve guide from the top of the cylinder head as shown in the illustration.
− Intake valve guide length: 45.5 mm
− Exhaust valve guide length: 50.5 mm
CAUTION:
The intake and exhaust valves are different
lengths, use care when replacing the valve
guides to install the correct valve guide.
• Install the valve guide to the specified height (1) of
14 mm.
• After installing the valve guide, insert the new valve and check for smooth movement.
Valve Seats
• Before machining the valve seat, check the clear-
ance between the valve guide and the valve stem.
If the clearance is excessive, repair the valve and
valve guide if necessary before machining the valve
seat.
• Repair the width and angle of the valve seat until
the valve seat meets specified values.
• After repairing the valve seat, use valve lapping
compound to lap the valves and seats in pairs.
Valve Seat Replacement
• Cut out a portion of the original valve seat and
remove the valve seat from the cylinder head.
• Select the replacement valve seat according to the
outer diameter of the enlarged valve seat.
REPLACEMENT VALVE SEAT SIZES
Intake valve seat
Enlargement size 0.30 mm
34.435 - 34.455 mm
Enlargement size 0.60 mm
34.735 - 34.755 mm
Exhaust valve seat
Enlargement size 0.30 mm
31.935 - 31.955 mm
Enlargement size 0.60 mm
32.235 - 32.255 mm
CYLINDER HEAD UNIT REPAIR
LTSM020106
LTSM020103
LTSM020104
02
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст