Hudson 1948 - 1952, Service Manual

Page: 82 / 333

3. Raise car and remove right front wheel and fender shield
with extension.
4. Remove both valve covers and breather pipe.
5. Using KMO-484 Valve Spring Lifter compress the valve
springs and remove spring keepers and retainers.
NOTE: Place corks or wood plugs in valve chamber oil
return holes to prevent valve locks from dropping through
these holes into the oil pan.
6. Remove valves from the engine and place them in a valve
rack to protect them from any damage and to insure that
the valves are returned to the same seats from which they
are removed.
7. Check all valves for warpage and burning, replace any
excessively burnt or warped valves.
8. Valves should be refaced on an accredited refacing
machine.
NOTE: The following chart used in conjunction with the
letters and dimensional lines in Figure 45, should be used
as a guide when performing any valve work.
NOTE: Seat diameter of valve head must be concentric
with valve stem within .002" total indicator reading.
Valve stem end should be ground flat and square with axis
within .002" total indicator reading.
A valve head face that is not concentric with the part of
the stem that operates in the guide will contact the valve seat
on only a small part of the total circumference. It will slap,
rattle, leak compression and affect valve timing.
Valve seats in the cylinder block should be cut with a
suitable valve seat cutter. The seats should be cut only
enough to remove pits and surface glaze. If seats are made
too
too wide in the cleaning up process, use a cutter with the proper
size pilot to obtain proper valve seat width. When reducing the seat
at cylinder head face use a 15° cutter and a cutter at port end.
FIGURE 45
A properly refaced valve will contact the valve seat throughout its
entire circumference e and the valve stem will "float" in the guide,
free from valve stem friction.
NOTE: The best valve grinding and aligning job will go for
naught if care is not used when tightening the cylinder head.
Always use a torque wrench and tighten the cap screws or stud
nuts in the sequence recommended to the following torque spec-
ifications 60-65 foot lbs. for both aluminum and cast iron heads
6 cylinder engines, 40-45 foot pounds for all 8 cylinder engines.
VALVE GUIDES:
Before reconditioning a valve seat it is important that the valve
guides be checked for wear.
Valve guides that are worn .003" more than the clearances
recommended in the following chart should be replaced.
3 - 40 ENGINE
INTAKE EXHAUST
6 cyl.
A- 45°
B- 1.831"
C- .1135"
D- .0495"
E- .083"
F- .016"
G- .054"
H- 1-11/16"
8 cyl.
45º
1.500"
.1135"
.036"
.0765"
.005"
.0575"
1-3/8"
6 cyl.
45º
1.561"
.1525"
.0496"
.103"
.008"
.075"
1-3/8"
8 cyl.
45º
1.375"
.1295"
.036"
.0935"
.0045"
.078"
1-7/32"
6 Cylinder
Valve Stem
Valve Guide
Exhaust
.3407
.3437
Intake
.3417
.3437
8 Cylinder
Valve Stem
Valve Guide
Exhaust
.3397
.3437
Intake
.3412
.3437