Specifications

1-12
GROUP 1-ENGINES AND EXHAUST SYSTEMS
Seat Width Scale
,
v
_^ CHECK DIAGONALLY
2) CHECK ACROSS CENTER
A1207-A
FIG. 11-Cylinder Head Flatness
guide cleaning tool. Use cleaning
solvent to remove dirt, grease, and
other deposits.
INSPECTION
Check the cylinder head for
cracks, and the gasket surface for
burrs and nicks. Replace the head
if it is cracked.
Cylinder Head Flatness. Check the
flatness of the cylinder head gasket
surface (Fig. 11).
Valve Seat Runout. Check the
valve seat runout with an accurate
gauge (Fig. 12). Follow the instruc-
tions of the gauge manufacturer. If
the runout exceeds the wear limit,
reface the valve and valve seat.
Valve Seat Width. Measure the
valve seat width (Fig. 13).
REPAIRS
Replace the head if it is cracked.
Do not plane or grind more than
0.010 inch from the cylinder head
gasket surface. Remove all burrs or
scratches with an oil stone.
Reaming Valve Guides. If it be-
comes necessary to ream a valve
guide (Fig. 14) to install a valve with
an oversize stem, a reaming kit is
available which contains the follow-
ing reamer and pilot combinations:
a 0.003-inch O.S. reamer with a
Runout Gauge
FIG. 13-Valve Seat Width
standard diameter pilot, a 0.015-inch
O.S. reamer with a 0.003-inch O.S.
pilot, and a 0.030-inch reamer with
a 0.015-inch O.S. pilot.
When going from a standard size
valve to an oversize valve, always
use the reamers in sequence. Always
reface the valve seat after the valve
guide has been reamed.
Refacing Valve Seats. Refacing of
the valve seats should be closely co-
ordinated with the refacing of the
valve face so that the finished seat
will match the valve face and be cen-
tered. This is important so that the
valve and seat will have a good com-
pression tight fit. Be sure that the re-
facer grinding wheels are properly
dressed.
Grind the valve seats of all engines
to a true 45° angle (Fig. 15). Remove
only enough stock to clean up pits,
grooves, or to correct the valve seat
runout. After the seat has been re-
faced, measure the seat width (Fig.
13). Narrow the seat, if necessary, to
bring it within limits.
If the valve seat width exceeds
the maximum limit, remove enough
stock from the top edge and/or
bottom edge of the seat to reduce
Tool-T58P-6085-B
352 AND 390 V-8
A1208-A
FIG. 12-Valve Seat Runout
Tool-T52L-6085- AEE
MILEAGE MAKER SIX
AND 292 V-
A1210-B
9L» « isa m
FIG. 14—Reaming Valve Guides
TO REMOVE STOCK
FROM BOTTOM \
OF SEAT, \
USE 60° WHEEL
45
TO REMOVE STOCK
FROM TOP OF SEAT,
USE 30° WHEEL
'VALVE SEAT WIDTH:
0.060-0.080
A1211-B
A1209-A FIG. 15-Valve Seat Refacing
the width to specifications (Fig. 13).
On the valve seats of all engines,
use a 60° angle grinding wheel to re-
move stock from the bottom of the
seats (raise the seats) and use a 30°
angle wheel to remove stock from the
top of the seats (lower the seats).
The finished valve seat should
contact the approximate center of
the valve face. It is good practice to
determine where the valve seat con-
tacts the face. To do this, coat
the seat with Prussian blue, then set
the valve in place. Rotate the valve
with light pressure. If the blue is
transferred to the center of the
valve face, the contact is satisfac-
tory. If the blue is transferred to
the top edge of the valve face,
lower the valve seat. If the blue is
transferred to the bottom edge of
the valve face, raise the valve seat.
VALVES
CLEANING
Remove all deposits from the
valve with a fine wire brush or buff-
ing wheel.
INSPECTION
The critical inspection points and
tolerances of the valves are illus-
trated in Fig. 16.
CHECK FOR
BENT STEM
— DIAMETER
FOR
DIMENSIONS
REFER TO
SPECIFICATIONS
DO NOT REMOVE ?
MORE THAN 0.010 !
INCH 1
VALVE
FACE
RUNOUT
A1OTO-A
FIG. 16—Critical Valve Tolerances