1938 Cadillac V16 - GM Heritage Center

Cadillac-LaSalle Preliminary Service Information 11
The 135° angle between the cylinder banks permits
uniformly spaced power impulses every 45°
to provide maximum smoothness of operation.
This wide angle permits an L-head valve arrangement
and convenient location of carburetors, distributors,
and other engine accessories.
The crankcase and cylinder block construction
follows, in general, the principles used in the V-8
engines. The crankcase casting has seven ribbed
bulkheads which add to rigidity and which, with
the front and rear walls, support the nine main
bearings. Bearing caps are of cast iron. Removable
shell type bearings of steel-backed babbitt are
used.
The cylinder heads are of cast iron, in accordance
with the usual Cadillac practice. The combustion
chambers are machined all over to avoid
compression pressure variations between cylinders.
The standard compression ratio is 7-0 to 1, which
necessitates the use of ethylized or other high
octane fuel.
The design of the crankshaft assures maximum
rigidity and smoothness. Dynamic balance is
achieved by the use of eight counterweights
forged integral with the shaft. Nine main bearings
resist bending forces while large bearing
journals with a %-inch overlap provide torsional
rigidity. (See Fig. 7.)
A rubber torsional vibration dampener is included
in the belt pulley assembly at the front of
the engine. It is similar in principle to the design
previously used, but is more compact. A "damped
bending" flywheel, as used on Cadillac V-8's, is
not required, due to the lighter power impulses
and the greater resistance to bending of the nine
main bearings.
•LOCKING SCREW
CONNECTING «00
CRANK PIN
Fig. 7. The 38-90 crankpin bearings overlap the crankshaft
journals
Fig. 6. The 38-90 V-16 engine has a single casting for cylinders and crankcase, with a 135° angle between the
cylinder banks