Continental L-Head Overhaul Manual - Igor Chudov

Page 46 CONTINENTAL L-HEAD ENGINE MANUAL
If the points are servicable, they should be
dressed down with a fine-cut stone or point file.
The file must be clean and sharp -- never use
emery cloth to clean contact points.
After filing, check the point gap and reset to
.020 -- the breaker arm must be resting on the
high point of the cam during this operation.
When replacing points, make sure they are
aligned and that they make full contact. Bend the
stationary arm to obtain proper alignment -- do
not bend the breaker arm.
4 -- Lubrication -- is required at the shaft, advance
mechanism, breaker cam and pivot. The
shaft may be either oil or grease cup lubricated
and should be given attention every oil change.
Make sure the breaker arm moves freely on its
hinge and apply a drop of light oil. A trace of
ball bearing lubricant such as Mobilgrease Special
(with Moly) should be used sparingly on the
breaker cam unless lubricated by a felt wick with
a few drops of oil.
CAUTION:
AVOID EXCESSIVE LUBRICATION -- AS
THE EXCESS MAY GET ON THE CONTACT
POINTS AND CAUSE BURNING.
SPARK PLUGS -- A spark plug consists of two
electrodes; one grounded to the outer shell of the
plug and the other well insulated with a core of
porcelain or other heat resistant material. The
space between these two electrodes is called the gap
which should be set at .025 on standard plugs, and
.035 on resistor type plugs for Continental L-Head
Engines. Correct and uniformity of the gaps of all
spark plugs in the engine is important for smooth
running.
GAP--
CERAMIC INSULATOR
~ -SEALS
LECTRODES
Figure 98 ~ Sectional view of spark plug
Spark plug gaps are best checked with a wire
gauge unless the points are dressed to obtain a correct
reading with a flat gauge. The adjustment
should always be made on the side electrode and
never on the center electrode which may cause a
broken porcelain.
"Gapping" the electrode tip is more easily done
with proper tools.
GAPPING THE SPARK PLUG. This illustration
shows the use of the gapping tool which both
measures and adjusts the electrode gap.
Figure 9Om Checking spark gap
Spark Plugs must operate within a certain temperature
range to give good performance -- not too
hot and not too cold. The abidty of a spark plug
to conduct heat away from the center electrode
and porcelain is controlled by the design of the
shell and insulator -- so varying the length of the
insulator below the gasket shoulder controls the
temperature.
COLD
PLUG
HEAT AWAY
FROM OORE HEAT AWAY
FROM CORE
SLOWLY
Figure 100 ~ Cold ~ Normal ~ Hot Spark Plugs
Cold-Normal-Hot Spark Plugs
Examination of a used spark plug will show if it
is in the correct heat range for the operating conditions.
If the plug runs too hot, the insulator will
blister or crack and the electrodes burn away
rapidly. If the plug remains too cool -- soot and
carbon will deposit on the insulator causing fouling
and missing.