1935 Cadillac - GM Heritage Center

97
ENGINE
General Description
The chief difference between the Cadillac and
LaSalle engines is that all of the Cadillac engines
are of the "V" type, while the LaSalle engine is of
the straight type with all of the cylinders in one
line.
CADILLAC
ENGINE
The Cadillac V-8 engines have a 90° angle
between the cylinder blocks. The intake manifold
is arranged to supply all cylinders with the same
amount of fuel mixture. Each of the four end
cylinders receives fuel through separate individual
passages. The intake manifold is heated by the
exhaust gas in the exhaust header.
These engines, as well as the 12- and 16-cyhnder
engines, are mounted in rubber at five points—one
at each side at the front, one at each side at the
rear of the crankcase and one at the rear of the
transmission. The support brackets at the front
end of the engine are at the sides of the front cover
and rest on the frame in the 370-D and 452-D and
on the X-member in the remaining cars. The
supports at the rear of the crankcase are attached
to the frame side bars and the one at the rear of
the transmission to a special cross-member connected
to the "X" member of the frame.
The 370-D and 452-D engines are of the same
general design, with a 45° angle between the
cylinders. This gives ample room on the outside
of the cylinder blocks for manifolds and carburetors.
A harmonic balancer is used on the front end
of the 370-D and 452-D crankshaft in addition to
counter weights forged integral with the crankshaft
cheeks.
The 370-D and 452-D engines have overhead
valves which are provided with an automatic
adjusting mechanism. This mechanism automatically
maintains zero valve clearance and
effectively overcomes the objectionable noise
usually characteristic of this type of valve.
The lubrication of all engines is full-force feed
to all bearings including the valve rocker arms on
the 370-D and 452-D. The oil filter on the 12-
and 16-cylinder engines is connected in the line
leading to the valve mechanism to eliminate any
possibility of foreign matter getting into the dashpots
of the automatic adjusting mechanism and
interfering with their operation.
The pistons on all engines are of the aluminum
alloy type with the wearing surfaces anodized by
an electrolytic process. This process greatly
increases the life of the piston as it provides a hard
aluminum oxide surface, being practically equivalent
to a hardening process.
The pistons are also finished slightly out of
round about .0065 inch on each side at the top
end. The initial contour of the pistons is such
that when the engine is heated to normal running
temperature, the pistons conform to the shape of
the bore. This piston design is very effective in
giving good engine performance due to the close
fit of the piston at running temperature.
The pistons are also slotted on both sides with
the slot in one side in the form of a "T." The
purpose of these slots is to compensate for expansion
of the piston.
The compression ratio of the 370-D and 452-D
may be changed by merely using a cylinder head
gasket of different thicknesses. To change to
lower compression a special gasket with a sheet
steel insert of a definite thickness between the
layers of asbestos should be used. This makes it
possible to change to a lower compression at a
very slight cost wherever the fuel situation
demands it.
This method of changing the compression ratio
is not practical on L-head engines, because of the
fact that it involves less expense to change cylinder
heads on an L-head engine.
The 12- and 16-cylinder engines are the only
Cadillac engines on which the factory sanctions
carbon burning. When this operation is performed
properly, the results are quite satisfactory
in these engines. On V-8 engines, however, where
it is a simple operation to remove the cylinder
heads without interfering with the valve mechanism,
the carbon can be removed to better advantage
by scraping.
Fig. 3. Details of Cadillac Pistons. LaSalle pistons
are same except for size and ring arrangement