Dodge RAM TRUCK 1500 1995 Service Manual page 964

B R
8.0L ENGINE 9 - 123
Service valves w i t h oversize stems are available
(Fig. 15).
Reamer O / S
Valve Guide Size
0.076 mm
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. 15 Reamer Sizes
Slowly t u r n reamer by hand and clean guide thor­
oughly before installing new valve. R e a m the v a l v e
guides f r o m standard to 0.381 m m (0.015 inch).
Use a 2 step procedure so the valve guides are
reamed true 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 45° face an­
gle and a 45° to 44 1/2° seat angle (Fig. 16).
CONTACT
POINT
A - SEAT WIDTH - INTAKE 1.016-1.524 mm ( 0 . 0 4 0 - 0 . 0 6 0 in.)
EXHAUST 1 . 0 1 6 - 1 . 5 2 4 mm ( 0 . 0 4 0 - 0 . 0 6 0 in.)
B - FACE ANGLE (INTAKE & EXHAUST)
C - SEAT ANGLE'(INTAKE & EXHAUST)
D - C O N T A C T SURFACE
J9409-133
Fig. 16 Valve Face and Seat Angles
VALWES
Inspect the remaining m a r g i n after the valves are
refaced (Fig. 17). Valves w i t h less t h a n 1.190 m m
(0.047 inch) margin should be discarded.
INTAKE
VMVE
STEM-
VALVE SPRING
RETAINER LOCK
GROOVE
EXHAUST
VALVE
J9209-127
Fig. 17 Intake and Exhaust Valves
VALVE SEATS
(1) When refacing valve seats, i t is important that
the correct size valve guide pilot be used for reseat­
i n g stones. A true and complete surface must be ob­
tained.
(2) Measure the concentricity of valve seat using a
dial indicator.
Total
runout should not exceed 0.038
m m (0.0015 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
valve seats should be 1.016-1.524 m m (0.040-0.060
inch).
VALVE SPRING INSPECTION
Whenever valves have been removed for inspection,
reconditioning or replacement, valve springs should
be tested. As an example the compression length of
the spring to be tested is 1-5/16 inch. T u r n table of
Universal Valve Spring Tester Tool u n t i l surface is in
line w i t h the 1-5/16 inch m a r k on the threaded stud.
Be sure the zero m a r k is to the front (Fig. 18). Place
spring over stud on the table and l i f t compressing le­
ver to set tone device. P u l l on torque wrench u n t i l
ping is heard. Take reading on torque wrench at this
instant. M u l t i p l y this reading by 2. This w i l l give the
spring load at test length. Fractional measurements
are indicated on the table for finer adjustments. Re­
fer to specifications to obtain specified height and al­
lowable tensions. Discard the springs t h a t do not
meet specifications.