Dodge RAM TRUCK 1500 1995 Service Manual page 871

B U S -
Fig. S Measuring Valve Guide Wear
Reamer 0 / S
Volve
Guide
Size
0.076 ram
8.026 - 8.052 mm
(0.003 in.)
(0.316-0,317 In.)
0.381 mm
8.331 -8.357 mm
(0.015 in,)
(0.328 -0.329 in.)
J9309-30
Fig. 7 Reamer Sizes
Slowly
turn reamer by hand and clean guide thor­
oughly before installing new valve. Ream the valve
guides from standard to 0.381 mm (0.015 inch).
Use a 2 step procedure so the valve guides are
reamed
t r u e
in relation to the valve seat:
• Step 1—Ream to 0.0763 m m (0.003 inch).
• Step 2—Ream to 0.381 m m (0.015 inch).
REFACING VALVES AND VALVE SEATS
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.
8).
VALVES
Inspect t h e remaining m a r g i n after the valves are
refaced (Fig. 9). Valves w i t h less t h a n 1.190 m m
(0.047 inch) margin should be discarded.
VALVE SEATS
CAUTION: DO NOT un-shroud valves during valve
seat refacing (Fig. 10).
(1) When refacing valve seats, i t is important t h a t
the correct size valve guide pilot be used for reseat­
ing stones. A true and complete surface must be ob­
tained.
3 J L ENGINE I • 27
CONTACT
i * •
A - SEAT WIDTH - INTAKE 1.016 - 1.524 mm (0.040 - 0.060 in.)
- EXHAUST 1.524 - 2.032 mm (0.060 - 0.080 in.)
S - FACE ANGLE (INTAKE & EXHAUST) 4374° - 43V.°
C - SEAT ANGLE (INTAKE & EXHAUST) 447.° - 44%°
D - CONTACT SURFACE
J9309-95
Fig. 8 Valve Face and Seat Angles
Fig. 9 Intake and Exhaust Valves
(2) Measure the concentricity of valve seat using a
dial indicator. Total r u n o u t should not exceed 0.051
m m (0.002 inch) total indicator reading.
(3) Inspect the valve seat w i t h Prussian blue to de­
termine where the valve contacts the seat. To do this,
coat valve seat L I G H T L Y w i t h Prussian blue then set
valve i n place. Rotate the valve w i t h l i g h t pressure.
I f the blue is transferred to the center of valve face,
contact is satisfactory. I f the blue is transferred to
the top edge of valve face, lower valve seat w i t h a 15°
stone. I f the blue is transferred to bottom edge of
valve face raise valve seat w i t h a 60° stone.
(4) When seat is properly positioned the w i d t h of
intake seats should be 1.016-1.524 m m (0.040-0.060