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ENGINES-8-CYLINDER
9-35
Fig. 7 7 4 n s p e c t i n g Valve Spring Squareness
49 to 57 pounds when compressed to
ll1ll6 inches and
137 to 150 when compressed to 15/16 inches for 273
and 318 cubic inch engines. For 361, 383, and 426
cubic inch engines see specifications. Replace springs
that do not meet specifications.
(2) Inspect each valve spring for squareness at both
ends with a steel square and surface plate, as shown
in Figure 77.
(3) If the spring is more than
'/I6
inch out of square,
install a new spring.
lnstallet ion
(1) Coat the valve stems with lubricating oil and
insert them in position in the cylinder head.
(2) Install new cup seals on the intake and ex-
haust valve stems and other valve guides, as shown in
Figure 78 and 79 and install valve springs and
re-
tainers.
(3) Compress the valve springs with Tool C-3422A.
Install locks and release tool.
NOTE: If the valves and/or seats are reground,
measure the installed height of springs. Make sure
measurement is taken from the bottom of the
spring seat in cylinder head to the bottom surface
of spring retainer. (If spacers are installed, measure
from the top of spacer.) If height is greater than
ll1lle
inches for
273
and
318
Cubic Inch Engines or
lS7/-
inches for
361, 383,
and
426
Cubic Inch En-
gines, install
a
'Ilo
inch spacer in head counterbore
to bring spring height back to normal.
HYDRAULIC TAPPETS
(361, 383 and 426 Cubic Inch
Engines
Only)
(1) Before disassembling any part of the engine to
correct tappet noise, check the oil pressure and the oil
level in the oil pan. The pressure should be 45 to 65
pounds at 1000 RPM.
Fig. 78-Valve
Assembly lDisassembled View1
(2)
The oil level in the pan should never be
above the "full" mark on the dipstick,
or below the
"add oil" mark. Either of these two conditions could
be responsible for noisy tappets.
(3)
Oil Level Too
High-If
the oil level is above the
"full" mark on the dipstick, it is possible for the con-
necting rods to dip into the oil while the engine is run-
ning and create foam. Foam in the oil pan would be
fed to the hydraulic tappets by the oil pump causing
them to go flat and allowing the valves to seat noisily.
(4)
Oil Level too
Low-Low
oil level may allow the
oil pump to take in air which, when fed to tappets,
causes them to lose length and allows the valves
to
seat noisily. Any leaks on the intake side of the pump
through which air can be drawn will create the same
tappet action. When the tappet noise is due to aeration,
it may be intermittent or constant, and usually more
w
RETAINER
SEAL-
Fig. 7 9 4 n s t a l l i n g Valve and Cup Seals
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