156—ENGINE
CHRYSLER SERVICE MANUAL
\ J73 REAM
IN
PLACE EXHAUST VALVE STEM GUIDE
/
\~~|RfcAM
IN
PLACE INTAKE VALVE STEM
GUIDEY
\
V' / /
MAXIMUM MEASUREMENT
51x36A
Fig.
15—Exhaust
and
Intake Valve Guides Installed
in Head (FirePower)
11.
REMOVAL AND INSTALLATION OF
VALVE GUIDES (FIREPOWER ENGINE)
Drive out guides through top of cylinder heads
with Tool C-3150. Install as follows: Turn cyl-
inder head with combustion chamber facing
up.
Drive valve guides into position with a suit-
able driver to dimensions shown in Figure 15.
After new valve guides have been installed,
ream each guide from .374 to .375 inch with
Tool
C-741.
Valves with oversize stems are
available in .005, .015, and .030 inch. Reamers
to accommodate the oversize valve stems are as
follows.
Reamer Tool C-3433 (.379 to .380 inch),
Reamer Tool C-3430 (.389 to .390 inch) and
Reamer Tool C-3427 (.404 to .405 inch). Slowly
turn reamer by hand and clean guide thoroughly
before installing new valve.
EXHAUST
VALVE
VALVE
SPRING RETAINER
LOCK
GROOVES
MINIMUM MEASUREMENT
54x330
Fig.
16—Intake
and
Exhaust Valve Nomenclature
Fig.
17—Checking Valve Stem Position (SpitFire)
CAUTION
Do not attempt to ream valve guides from
standard directly to .030 inch. Use step pro-
cedure of .005, .015, and .030 inch so the valve
guides may be reamed true in relation to valve
seat.
12.
REFACING VALVES
AND
VALVE SEATS
The intake and exhaust valves are faced to a
45 degree angle. When refacing valve always
check remaining margin (Fig. 16). Valves with
less than %
4
inch margin should be discarded.
The angle of both valve and seat should be
identical. When refacing valve seats with Tool
MTH-80,
it is important that correct size valve
guide pilot be used for reseating stones. A true
and complete surface must be obtained. Check
concentricity of valve seat using a dial indica-
tor; total runout should not exceed .002 inch
(total indicator reading). When the seat is
properly positioned, width of intake seats
should be y
16
to %
2
inch. The width of exhaust
seats should be %
4
to y
le
.
When valves and seats are reground, the po-
sition of valve in head is changed, shortening
operating length of hydraulic tappet. This
means that plunger is operating closer to its
bottomed position, and less clearance is avail-
able for thermal expansion of valve mechanism
during high speed driving. Design of plunger
travel includes a safety factor for normal wear
and refacing of valves and seats. The dimen-
sion from valve spring seat in head to valve
tip should be checked with Gauge Tool C-3436
for SpitFire Engines and Gauge Tool C-3061
for FirePower Engines, (Figs. 17 and 18).
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