1935 Cadillac - GM Heritage Center

105
practicable. Burning the carbon, if properly
done, will give good results on these engines at a
much lower cost to the owner.
If this method is used, the carbon should be
allowed to burn slowly to obtain the best possible
results. Quick burning will do only a partial
job. The rate of combustion can be controlled
by the proper regulation of the oxygen supply to
the combustion chamber.
While the carbon is being burned, particular
care must be taken to prevent injury either to
the valves or to the external fittings on the engine.
The proper procedure is as follows:
Remove the spark plug wires and distributor
cover, or use a suitable asbestos cover plate to
protect them during the burning operation.
Remove all spark plugs.
ENGINE
The next step is a matter of extreme importance,
that is, to be sure the valves are both closed in the
cylinder being burned. If the valves are not
closed, they are very likely to be overheated,
causing them to warp.
The only positive way to make sure the valves
are closed is to use a test light and crank the engine
to the firing point on that cylinder. See Fig. 20,
Plate 38.
Allow the carbon to burn slowly until it has all
been burned.
Burn out all of the left-hand cylinders first, in
the order in which they fire; then burn the right
hand cylinders. The firing order, is, of course,
indicated on the distributor cap.
Removal of carbon in the V-8 engines should
be done by scraping as in the past.
14. Main Bearing Clearance
Use dial indicator and special fixture (Tool No
HM-65530) for checking bearing clearances. If
bearings are found to be worn beyond specified
limits they should be replaced. Replacement
bearings are furnished to exact size and do not
require reaming or scraping. No shims or liners
are used on the main bearings and no attempt
should be made to take up if worn.
Always install new wooden plugs in grooves in
sides of rear main bearing cap in Cadillac engine
to prevent oil leaks around the cap. These plugs
should be well greased to facilitate installation in
the grooves.-
15. Cleaning Oil Filter on 370-D and 452-D
A Cuno disc-type self-cleaning oil filter is used
on the 370-D and 452-D cars.
The oil, in circulating through the filter, passes
between thin rotating discs, stacked one upon
another, and separated a few thousandths of an
inch by a series of thin stationary plates. The
filtering discs are mounted on a shaft which
extends above the filter and is connected to the
brake linkage in such a way that the discs are
rotated a partial turn each time the brakes are
applied. -
When the filtering discs are rotated the accumulated
sediment is scraped off by the stationary
plates and falls to the bottom of the tank.
The only attention required is the draining of
the tank every 6000 miles.
16. Using Stud for Removing V-8 Cylinder
Heads
The cylinder blocks used on Cadillac V-8 cars
are not equipped with studs for attaching the
cylinder heads. Instead, cap screws are used
because of the necessity of turning the head
slightly counter-clockwise, when removing, to
clear the hood shelf.
When removing or installing cylinder heads,
particular care must be taken to hold the head in
position. If this precaution is not taken, there is
a possibility of the head striking and bending
those valves which are open.
Fig. 16. When removing the cylinder head on V-8
engines, replace one of the center cap screws with a
stud before removing the remaining screws to prevent
the head from sliding down and damaging the valves.
A good way to avoid this possibility is to
replace one of the two center cap screws with a
stud before removing the remainder of the screws
as shown in Fig. 16. The head will then be held
in position until it is lifted off, pivoting on the one
stud when turned to clear the hood shelf.
A stud can be made by sawing off the head of a
-r\ in. x 14 American National thread cap screw,
about 3 in. long. The cap screw, part number
122340, used at the front and rear bumper tube
support brace can be used for this purpose.
17. Adjusting Cadillac Engine Supports
Before aligning the engine, all supports should
be loosened and the intermediate engine support
brackets should be loosened from the frame by
removing the bolts from the casting.
The intermediate support bracket is attached
to the frame by means of three bolts, the two
lower ones with the heads inside of the channel of
the frame side bar with the nuts toward the engine.
The upper bolt faces the opposite direction with
the head toward the engine and the nut inside the
side bar channel. On later cars, an opening has