1938 Cadillac V16 - GM Heritage Center

new plugs if the old plugs are badly worn. A.C. Spark
Plug Model 45 is recommended for Cadillac V-16 cars.
Cleaning the timer contact points in the distributor and
setting to a gap of .012-.018 inch. Replace contact points if
they are badly worn.
Retiming the ignition to the timing marks on the harmonic
balancer at the front of the engine.
Carbon and Detonation—Most automobile owners
have been taught that a detonation or "ping" in the engine
is an indication of an over-advanced spark or of carbon in
the engine, and probably the latter. While this is true, the
following supplementary information must be included when
considering "ping" in any high compression engine.
On cars with high compression engines, slight detonation
occuring on rapid acceleration at low speeds and disappearing
at about 15 miles per hour, is normal and indicates that
the engine is performing at top efficiency. Detonation at
higher speeds can be eliminated by checking and correcting
the following:
Grade of gasoline used—The Cadillac V-16 engine is
designed for use with premium (ethylized) fuels. Gasoline
of a lower rating should not be used.
Over-lean-mixture—This may be due to an incorrect
carburetor adjustment or to an obstruction in the fuel feed.
Spark plugs—One or more faulty spark plugs will cause
pre-ignition in their respective cylinders. Replace these
with A. C. model 45 spark plugs.
Accumulation of Carbon—Accumulated carbon can be
removed by scraping after taking off the cylinder head.
Removal of carbon by burning is not recommended.
Carburetor—The only adjustment required by the
carburetors is the idling adjustment.
The idling speed should be set with the throttle stop
screws to the equivalent of 6 miles per hour. The idle
needle valves should then be adjusted until the engine runs
smoothly. These adjustments must be made when the
engine is hot.
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Accurate synchronization of the two carburetors is
essential to good engine performance. This can be done
most satisfactorily at an Authorized Service Station.
Air Cleaner—Your Cadillac V-16 car is fitted with air
cleaners of the "oil bath type," which operate very efficiently
in removing dust from the air drawn into the engine. As
this type of cleaner accumulates considerable dust and
dirt, it requires regular cleaning every 2,000 miles, or
oftener if extreme conditions are encountered.
The cleaners are cleaned and re-oiled in the following
manner:
Remove the gauze units and wash thoroughly
in gasoline, taking particular care to
wash all the accumulated dirt and dust out
of the wire mesh.
Dry all the units thoroughly, either with
compressed air or an adequate drying period.
Pour one pint of S.A.E. 50 engine oil (S.A.E.
40 in winter) in each reservoir and assemble
the wire mesh and cap.
NOTE: No oil should be placed on the wire
mesh.
Gasoline Filter—Gasoline filters are provided at the
fuel pumps on the front of the engine. Any accumulation
of water or sediment should be cleaned out when it can be
seen in the glass bowls. Remove the bowls by unscrewing
the thumb nut and swinging the yoke to one side. If the
screen strainer sticks, remove it by pulling straight up.
Any dirt on the strainer should be washed off with gasoline,
and the bowl should be wiped clean. Then reinstall
screen and bowl, making sure the bowl seats properly against
the cork gasket and tighten.
Other Service Operations—Major service operations
on the engine, such as valve grinding, replacement of bearings
or reconditioning of cylinders, should be performed only by
experienced workmen having the necessary instructions and
equipment.
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