1938 LaSalle Production - GM Heritage Center

automobile. For further Cadillac refinement, however,
this new type . of flywheel has been designed which
results in a silky smoothness never previously achieved.
Instead of the usual rigid flywheel, the cast iron rim
of the new design is attached to the crankshaft by a
flexible steel disc. Damping plates press against both
sides of this flexible disc. When the engine is run at
speeds at which crankshaft bending occurs, the flexibility
of the disc permits the cast iron flywheel rim to
run in a true circle regardless of crankshaft deflection.
If the crankshaft bends, however, the damping plates
rub against the flexible disc, thus absorbing or damping
the motion of the crankshaft just as the vibration of a
violin string is damped if the finger is placed upon it.
All Cadillac V-8's also have a torsional vibration
dampener on the crankshaft. While torsional or twisting
vibrations are characteristic of crankshafts in all sixes,
straight eights and V-12's, they are for all practical
purposes eliminated by the short crankshafts of four
cylinder and V-8 design engines. The dampener is used
on Cadillac solely as an additional refinement to a
powerful engine.
Main
Bearings
Due to the inherent cancellation of inertia forces in 90°
V-type design, main bearings have no work to do other
than support the crankshaft and absorb combustion
forces. Hence, only three are necessary. These are
rigidly backed and babbitt-lined. They have very wide
surface areas which retain oil longer than seven or nine
small bearings. Three bearings are more easily aligned
and more easily accessible.
A new positive rear main bearing oil seal is used in
addition to the slinger-type seal. This design consists of
an asbestos composition packing being held in the
crankcase and main bearing cap by metal retainers.
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