Mitsubishi 4d68 User Manual
4D68 ENGINE (E-W) -
Cylinder Head, Valves and Valve Springs
11A-9-5
VALVE
(1) Check the valve face for correct contact. If incorrect, reface
(1) Check the valve face for correct contact. If incorrect, reface
using a valve refacer. Valve seat contact should be
maintained uniform at the center of valve face.
(2) If the margin is smaller than the service limit, replace
the valve.
Standard value: 1.5 mm
Standard value: 1.5 mm
Limit: 0.7 mm
(3) Measure the overall height of the valve. If the specified
limit is exceeded, replace the valve.
Standard value:
Standard value:
Intake
114.05 mm
Exhaust
113.80 mm
Limit:
Intake
113.55 mm
Exhaust
113.30 mm
VALVE SPRING
(1) Measure the free height of the spring and, if it is smaller
(1) Measure the free height of the spring and, if it is smaller
than the limit, replace.
Standard value: 49.1 mm
Standard value: 49.1 mm
Limit: 48.1 mm
(2) Measure the squareness of the spring and, if the limit
is exceeded, replace.
Standard value: 2° or less
Standard value: 2° or less
Limit: Max. 4°
VALVE GUIDE
(1) Measure the clearance between the valve guide and valve
(1) Measure the clearance between the valve guide and valve
stem. If the limit is exceeded, replace the valve guide
or valve, or both.
Standard value: 0.05 - 0.09 mm
Standard value: 0.05 - 0.09 mm
Limit: 0.15 mm
VALVE SEAT
(1) Check the valve seat for trace of overheat and contact
(1) Check the valve seat for trace of overheat and contact
with valve surface.
Standard value: 0.9 - 1.3 mm
Standard value: 0.9 - 1.3 mm
PWEE9609
E
Dec. 1996
Mitsubishi Motors Corporation
6EN0542
Valve seat
contact
Margin
1EN0264
Free
height
6EN0279
Guide I.D.
Stem O.D.
1EN033
Valve contact
width