Evening star. [volume] (Washington, D.C.) 1854-1972, 1927-01-23
Opened by the Throttle.

/
| Just when Smith thinks he has
delved into every possible subject re
garding his car and his motoring,
some simple thing suddenly dawns
upon him as subject that he has
completely overlooked. Recently he
hanDened to be sitting at the wheel
| having a little fun by himself, in a
sort of absent minded way. idling and
racing the engine alternately. We'll,
of all things" he thought. Here I
am just getting acquainted with the
throttle"
The throttle is a big subject in
itself. He could not grasp it all in
one sitting but some of the things he
discovered as he sat there fussing
with the hand gasoline control are
worth recording.
IT noticed for the first time that
while the hand lever controls the &C
celerator the latter does not govern
the position of the hand lever" he
, said when we were discussing it later
This is a very simple matter, yet it
means, much. 1t means. for one thing,
that if ! take my foot off the accel.
orator while the hand lever is higher
than the idling position, the effect is
the same as if | still held my foot on
the accelerator That might be dan
gerous in a pinch.
Il can see where II Is advisable
to have a spring working on the
hand lever as we'll as on the &C.
celerator, so that if [ should forget
to push the hand lever back to the
idling position when about to stop
or shift gears it would go back of
its own accord. just as the accel
orator pedal comes back to the off
position"
Springs Role Important.
while I think of it," | Interrupted,
"one of the important things about
the throttle is the rate of speed at
which it closes. When you take your
foot off the accelerator the spring
attached to 1t almost instantly closes
the throttle to the idling position.
This is important when you want
to make a quick stop, because, as
you probably know. the engine can
be an excellent brake. Its own COM
preston Is a means of retarding the
speed of the car, provided you cut
down the gas to a point where the
engine would have practically no pow
er to drive the car. If your throttle
is sluggish in closing, naturally the
engine is slower to go into action as
a brake.
Your hand control of the throttle
pulls down for speed and pushes up
for idling, and is not equipped with
a spring. In other words, it stays
where you happen to put it, and must
be pushed back if you happen to have
advanced it, which you might do IL
driving the car in some tight place
where you need your feet on both
clutch and brake pedals. Where the
hand levers work up for speed and
down for idling the situation is little
better. The lever tends to drop or
slide back to the idling position be-
cause of the bouncing of the car
Vacuum Tank Affected.
Something that Smith hadn't no.
ticed before was that the throttle
had lot to do with the functioning
Of the vacuum tank. the vacuum sue
ton windshield wiper. the lubricating
system and other things as well.
When l told him about this he was
astounded and wanted proof. So we
started a demonstration.
With the windshield wiper going I
showed him how / could stop it alto
gether by sudden opening Of the throt-
tie, as in acceleration. Opening the
throttle diverted suction from the
small suction pipe which is connected
into the intake manifold just above
the throttle. This was simple enough.
Next / showed him how to speed
up the wiper when. as 1t often hap
pens on hills, the device slows down
or stops altogether. / simply lifted
my foot from the accelerator for an
instant This closed the throttle and
created an intense suction through
the wiper tube. The wiper went back
into action Immediately and with a
vengeance Smith decided that this
was important when driving through
the rain, even if it meant dropping
back into second gear.
The vacuum tank fills most rapidly
when the throttle is closed and the
engine is turning over fast. That,
as / explained 10 him, is because the
air which the revolving engine sucks
in must go through the suction pipe
and the idling jets of the carburetor,
rather than through the high-speed
openings of the carburetor. which
then are closed by the throttle.
Tank May Go Dry.
II conditions are just right, and
IL the car travels too slowly with the
throttle rather far open, suction is
taken from the vacuum and 1t may
go dry. Such a condition occurs IL
one drives too slowly up a long, steep
grade. The throttle has to be rather
wide open for such performance, and
the car must drag.
Next we shot the speed of the car