Los Angeles herald., 1910-10-16
ENGINE MUST BE PERFECT
FIT TO BALANCE CAR

Perfect smoothness of running can
only be secured by fitting the car with
we'll l-balanced engine. This would ap-
pear to be a very easy matter as al
most every maker of a gasoline engine
claims that it is perfectly balanced,
whether it be a single-Cylinder one,
a tWo-cylinder, three-cylinder, or
whatever number of cylinders it may
have. In fact, when balancing is thus
referred to, a very loose interpreta-
tion of the word is, or should be, in
tended The balancing of a recipro-
eating engine might appear at first to
represent the very simple problem
which, in the single-cylinder engine, is
usually solved by forming weights on
the crank arms to balance the re-
Volving and reciprocating masses; but
after this has been done without go
ing into refinements that would be of
interest to an engineering student, but
could scarcely be followed by the gem
eral reader), there remain in the YER
tical engine unbalanced inertia forces,
caused by the moving parts, which
produce a vertical hammering action
Now, if instead of a single-cylinder
engine with cranks at $50 degrees and
reciprocating masses equal, there are
certain forces and couples which can
not be balanced and they result in a
fitting effect which tends to rock the
engine in a fore and aft direction and
causes serious vibration. But with
three cylinders, with equal masses at
the crank radius and the cranks at
$50 degrees, and reciprocating masses
equal, there are certain forces and
couples which cannot be balanced, and
they result In fitting effect which
tends to rock the engine in a fore ana
IL, u
bration. But with three cylinders,
with equal masses at the crank
radius, and the cranks at 120
degrees, the engine can be ar
ranged to run with a more uniform
turning action and with the vertical
hammering action practically elimi-
mated, a distinct advantage over the
two-cylinder one; but, so far as the
rocking action, due to certain unbal-
anced couples, is concerned, this en-
CINE has little or no advantage over
the two-cylinder one of the same
power. Now, by adding another cylin-
der, we get a four-cylinder engine,
which gives the designer much better
chance Of approximating to true bal
ance, for with cranks at $50 degrees
apart, the usual arrangement in motor
car engines, a perfect fore and aft bal
ance is possible; but the vertical ham
mering erect can only De lmperIectly
dealt with, in fact, with no more sue
cess than in a two-cylinder engine.
Notwithstanding this. it cannot be de-
MED that our-cylinder engines are
produced which, when run at the speed
they were designed to work at, are
hard to beat for smoOthness of run
ming. But those who have paid atten-
tion to these matters will know that
to attain the highest possible condi-
tion of balance in an engine six cylin-
ders are necessary. Even with the re-
ouired number OF cylinders the eXer-
else of consummate skill in designing
the balance system is necessary to pro-
duce an engine that will run without
vibration; indeed. wealth of mechan-
ical genius has been iavished on the
evolution of the highest form of gaso-
line engine and some elegant expedl-
ents have been devised in solving bal
ancing problems. So it will be seen
that balancing of engines Is subject
on which the man in the street is not
likely to be very well informed. In
fact, is most likely to be easily mis-
led