Dodge Dakota Sport 2001 Service Manual page 1055

9 - 26 ENGINE 2.5L
ROCKER ARMS (Continued)
the pivot contacts. Install rocker arms, pivots and
bridge above each cylinder in their original position.
(3) Loosely install the capscrews through each
bridge.
(4) At each bridge, tighten the capscrews alter-
nately, one turn at a time, to avoid damaging the
bridge. Tighten the capscrews to 28 N·m (21 ft. lbs.)
torque.
(5) Install the engine cylinder head cover (Refer to
9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
Both the intake and exhaust valves are made of
steel. The intake valve is 48.768 mm (1.92 inches) in
diameter and the exhaust valve is 41.148 mm (1.62
inches) in diameter and has a 2.032 mm (0.080 inch)
wafer interia welded to the tip for durability. These
valves are not splayed.
STANDARD PROCEDURE—VALVE TIMING
VERIFICATION
• Disconnect the spark plug wires and remove the
spark plugs.
• Remove the engine cylinder head cover.
• Remove the capscrews, bridge and pivot assem-
bly, and rocker arms from above the No.1 cylinder.
• Alternately loosen each capscrew, one turn at a
time, to avoid damaging the bridge.
• Rotate the crankshaft until the No.4 piston is at
top dead center (TDC) on the compression stroke.
• Rotate the crankshaft counterclockwise (viewed
from the front of the engine) 90°.
• Install a dial indicator on the end of the No.1
cylinder intake valve push rod. Use rubber tubing to
secure the indicator stem on the push rod.
• Set the dial indicator pointer at zero.
• Set the dial indicator pointer at zero.
• Rotate the crankshaft clockwise (viewed from
the front of the engine) until the dial indicator
pointer indicates 0.305 mm (0.012 inch) travel dis-
tance (lift).
• The timing notch index on the vibration damper
should be aligned with the TDC mark on the timing
degree scale.
• If the timing notch is more than 13 mm (1/2
inch) away from the TDC mark in either direction,
the valve timing is incorrect.
• If the valve timing is incorrect, the cause may be
a broken camshaft pin. It is not necessary to replace
the camshaft because of pin failure. A spring pin is
available for service replacement.
STANDARD PROCEDURE—REFACING VALVES
AND SEATS
VALVE REFACING
The intake and exhaust valves have a 43-1/4° to
43-3/4° face angle and a 44-1/4° to 44-3/4° seat angle
(Fig. 19).
Fig. 19 Valve Face and
1 - CONTACT POINT
A,B,C and D Refer to VALVE FACE AND VALVE SEAT ANGLE
CHART
VALVE FACE AND VALVE SEAT ANGLE CHART
ITEM DESCRIPTION
A SEAT WIDTH
INTAKE
EXHAUST
B FACE ANGLE
(INT. AND EXT.)
C SEAT ANGLE
(INT. AND EXT.)
D CONTACT
SURFACE
Inspect the remaining margin after the valves are
refaced (Fig. 20). Valves with less than 1.190 mm
(0.047 in.) margin should be discarded.
AN
SPECIFICATION
1.016 - 1.524 mm
(0.040 - 0.060 in.)
1.524 - 2.032 mm
(0.060 - 0.080 in.)
43¼° - 43¾°
44¼° - 44¾°
—