The Salt Lake herald-Republican. [volume] (Salt Lake City, Utah) 1909-1918, 1910-05-08
LUNGS /
ARE MADE Strong.
New Carbureter Design Said to
Furnish Exactly What
Is Wanted.
ENGINE DRAWS IN THE AIR
VENTURE TUBE KEY TO EFF
CIENCY OF IMPROVEMENT.
By GEORGE ). DUNBAR.

No detail OF automobile construction
has been responsible for so many ex-
periments as the development of carbu-
rotor design. Research and constant
application OF g carDuretor. truly called
the lungs Of a car" that furnishes a
mixture which is right at both high and
low speeds-an end long sought after.
To do this we provide combination
OF three Ventura tubes placed in the
intake pipe of the carburetor, each tube
concentric with the others. but in vary
ing positions longitudinaIly. Into the
three, we admit the gasoline from the
spray nozzle. The amount of vacuum
or suction being greater as the speed
of the passing air increases, II follows
that II the speed of the air at low
engine speed is very high over the top
of the spray nozzle 1t will draw q COM
paratively large quantity OF gasoline
with II, and 1t will do this through a
Inasmuch as the friction of liquids
through 3 small orifice increases rap
idly with the speed at which 1t Is
even though a greater force were ex-
erted. tending to draw this liquid
through the orifice. one would not get
additional liquid in proportion to the
Engine Draws the Air.
We have a definite speed of air
engine speeds and this speed increases
with the engine speed. although not as
fast. The means Of obtaining the re-
latively high air speed at low engine
speeds. and obtaining It in such g
manner that the maximum quantity of
air and gasoline necessary to entirely
fill the cylinders Will be admitted at
high speeds. is the problem that we
have solved.
The method OF doing this is to make
what might be termed a three stage
Ventura tube carburetor. in which the
engine draws the air through the out
side tube at speed varying with the
speed Of the engine.
The Ventura tube is a tube which is
constructed in the center so that the
speed of the air at the center of the
tube is greater than at either end A
sectional view of the inside of this tube
would present somewhat the appear
ance of an elongated hour glass.
The three tubes are arranged so that
the large end of one of them comes at
about the center of the one surround
ing 1t Each successive tube being
placed away from the engine or the
side from which the suction is induced.
If the speed of the air through the
outer or largest tube at either end is
ten feet per second the speed in the
center will be, for example, twelve
the speed of the air surrounding the
ENDS of the second or intermediate
tube If this is twelve feet per Sec
ond the speed Of the air in the center
u Tie SCSOnQ OF intermediate TUBE
might be taken at fourteen feet
This increased velocity Is due to the
fact that the largest tube is injecting
air into the intermediate tube, which
IN turn is performing the same func-
ton for the smallest tube, with the re-
suit that the final air velocity over the
gasoline nozzle would be considerably
greater than the velocity of the air
through hole of equal size not having
the additional tube
The effect of this arrangement, in
addition to furnishing the proper mix
ture automatically at all running
speeds, is to furnish proper mixture at
ordinary cranking speeds, and as a re-
suit the steadiness so essential