Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1920-10-10
.S|MPL|F|ED LESSONS IN
CARE OF AUTOMOBILES
Expert Gnclrlich Explains tho
Special Carburcter Used on
Ford CprS

There Is ono carburctor. namely
/, The one used on the Ford cars, which
because II operates on different
and because of the great number OF
these cars I'm use. demands specia!
explanation.
known as the puddle or surface car
buretor. Al the higher speeds. how
ever, 1t is really spray carburctor.
We learned that the easoline will
liquid 10 n gas at a temperature OF
about 30 degrees. when under atmos-
ppherio pressure: but at much lover r
less than atmosphere. or a vacuum.
Thus. II we had a puddle OF gasoline
IN a vessel and we've 10 create n
vacuum over. the puddle. tho gasoline
would vaporizc.
II a current of air were TO pass
over this puddle At a fair rate Of
speed the tendency TO .vaporize would
agitation OF the liquid and partly be-
cause OF the friction Mt tho surface
Of the liquid the air will carry with
it some fine particles OF the liquid.
and also because this friction will
make the top of the LIQUID warm.
:. 1t Is on the above principle that The
Ford carburetor is designed.
from the supply tank. sc" the iioat
chamber, with It's cork noat valve.
M and ID. is the puddle chamber.
liquid in the float chamber is slight
iy-one-eishthN of an inch in prac-
tice-higher than the bottom OF the
puddle chamber: thus there will be
a thin puddle OF gasoline in the cham
Der.
Note that because OF the curve in
race or area OF the top OF the puddle
VIII be greater when the depth or
thickness Of the puddle is increased.
and vice versa.
us no &c
cause of the suction stroke. q vacuum
Will form in the manifold III" and
SO In the puddle chamb Der, with the
result that the gasoline willvdporizc
air viii enter at "F'' and go carry
this gas to the cylinder. mixing with
IL on the way thereto.
How IS the proportion OF gasoline
70 air in the mixture controlled or
regulated? AS the gasoline vaporizes.
the puddle Will disappear or become
Ter 20 take the place Of that used.
Now. If we were TO control the en-
trance OF this fresh gasoline so as 10
Keep the puddle NJ certain thickness
top of the puddle. or the surface from
which the gas can vaporizc to 4 GER
tain amount and we would thus con-
troll the per cent OF gas in the mix
turc.
Tho entrance OF the fresh gasoline
IS controlled by the needle valve &c"
Obviously. as this needle is screwed
down the mixture will he learcr or
weaker, and when screwed up richer
AS matter OF fact, the amount OF
gasoline which will vaporize will be
exactly tho amount which will enter
through the hole ~" or needle valve
because of the greater vacuum al the
higher speeds. more gas will enter
through this opening, just ms II does
through the spray nozzle of the car
vuretor explained previously.
The above lie the action at the lower
speeds, but at the higher speeds all
OF the puddle Will be swept away, so
that the needle valve ~" will really
become spray nozzle, its action he-
ing much the same as that of the noz-
g,c OF the spray type Of Cartureto-
TX in the Illustration is the but
terfy or throttle valve operated bv
the lever M" which lever is in turn
operated by the lever on the steering
cnlumn. Notice the screw Il" called
the stop screw. The purpose Of this
i IN determine the idling speed OF
the engine; hat is, its speed when 1t
y running, but the car = standing
stun. as when az the curt Or IN traffic
lou Will note that x determines the
amount the throttle valve can be
closed. AS Il is screwed back II al
lows the throttle to close more. and
so the engine VIII 60 slower while IL