Section 01 ENGINES (1503 4-TEC)
Subsection 06 (CYLINDER HEAD)
VALVE GUIDE PROTRUSION
MINIMUM
12.4 mm (.4882 in)
MAXIMUM
12.8 mm (.5039 in)
NOTE:
For lubrication of the reamer use only cut-
ting oil. Turn the reamer only forward, in cutting
direction, never backward. Clean the reamer at
short intervals from swarf, moving the reamer on-
ly while turning in cutting direction.
Ream the new valve guide with a reamer 6 mm
diameter.
Clean cylinder head carefully. Check that the valve
seat is concentric with the new guide axis (check
contact surface with engineer's blue).
Valve Face and Seat
1
2
R1503motr107A
3
1. Valve seat
2. Exhaust valve contaminated area
3. Valve face (contact surface to valve seat)
Check valve face and seat for burning or pittings
and replace valve or cylinder head if there are signs
of damage.
Ensure to seat valves properly. Apply some lap-
ping compound on valve face and work valve on
its seat with a lapping tool.
Measure valve face contact width.
NOTE:
The location of contact area should be in
center of valve seat.
Measure valve seat width, using a caliper.
VALVE SEAT CONTACT WIDTH
NEW
Exhaust
1.25 to 1.55 mm
(.049 to.061 in)
Intake
1.10 to 1.30 mm
(.043 to.051 in)
SERVICE LIMIT
Exhaust
2 mm (.078 in)
Intake
1.8 mm (.07 in)
If valve seat contact width is too wide or has dark
spots, replace the cylinder head.
V01C1HA
B
A
A. Valve face contact width
B. Valve seat contact width
Valve Seat Grinding
NOTE:
The valve seats may be reground with
a valve seat grinder which centers on the valve
guide.
– Grind the valve seat at 45°. Remove no more
material than absolutely necessary to clean the
seat up.
– Using a 35° stone, narrow the valve seat until
the appropriate outer diameter is obtained.
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