El Paso herald. (El Paso, Tex.) 1901-1931, 1918-03-23
Engine Types of Today
Popular Science Expert Deals With the -Four Popular
Types; Poppet Valve, Knight, Air Cooled and
Steam and Tells Advantage of Each.


z n THE somewhat more than Is
years since the American motor
car passed from the experimental
stage. no part OF the mechanism has
gone through a more interesting
process OF evolution than the engine
or motor. as It IS commonly called
Many types OF power plants have
come and gone and today construc-
tion has practically standardized four
types the conventional pOppet valve
design. the air cooled engine, the
sliding sieve OF knight motor and
the steam power plant
In the years that have gone before
we have seen many other types make
bids for popularity and for some rea-
son or other fail The list Includes
the rotary valve engine, the revolv-
ing cylinder. cscillating sleeve de-
signs, piston valve engines. two cycle
plants and others. Today there Is the
Diesel. e definite type. which has not
yet been tried for passenger car work,
but which looms Up as a possible de-
velopment OF the future.
We shall concern ourselves first
with the four types that hold the
center OF the passenger car stage to-
day as they alone are OF practical
Interest to motor car owners. The
poppet valve engine IS the prevailing
type. Nor are the reasons far the su-
premacy Of this type Of power plant
far TO seek II Is cheap to manu-
facture, IS simple in operation, IS re-
liable and generally efficient. It is
difficult 20 beat this array u quail
6cations
The poppet valve engine has the In.
take and exhaust valves placed at
some location in the cylinder head
In the pOppet valve engine, the valves
or devices for controlling the flow Of
gasses 70 and from the cylinder, are
In the form OF mechanically operated
discs. Take a silver dollar, bevel the
edge and fasten a stem peucil-shaped
to the center and you have q pOppet
valve IN appearance. The stem Is
moved by mechanical connection, BY
means OF a cam, so that as the cam
turns around II strikes the inter
mediary which in turn pushes the
valve upward. The valve is closed by A.,
spring pressure. This type OF engine ]
Is used on practically all modern l
automobiles While Il has been dem
onstrated that other types OF engines I
may give better service under certain /
conditions, II is almost automatic that /
the poppet valve type gives greater /
returns on an equal expenditure and 1
this Is why Il finds place on most I
OF our passenger motor cars.
The air cooled engine Is used today l
by two makers, Franklin and Holmes. |
Both these engines are OF the pOpper ]
valve type, but their radical differ I
5nce In cooling method certainly en-
titles them TO distinct classification.
among the obvious advantages OF I
the air cooled power plant. one Of the I
chief Is the saving IN weight through I
the elimination OF the radiator. water I
Jackets, pump, etc. The freedom /
from freezing in winter Is 8 point I
that the past few months have served /
10 emphasize. The air cooled engine i
shows certain definite economies over I
It's water cooled rival. principally \
through the weight saved. However
the water cooled engine OF the same /
size as an air cooled one, will give a 1
greater power output In ordinary
service the question OF power produc-
ton Is not q paramount one After I
enough power IS assured. more is
simply excess, so that the air cooled /
limitations in this direction
are more theoretical than real
The Knight sliding sleeve valve en-
CINE Instead OF the ordinary popDet \
valve. utilizes sliding sleeves inside ]