The Bismarck tribune. [volume] (Bismarck, N.D.) 1916-current, 1926-02-27
'kNlCKTTYPE
MOTOR CALLED
ECONOMICAL

During the past five years, the de-
mands put on the power plant Of the
automobile have increased by leaps
and bounds.
The increasing price for fuel has
set up an even greater demand for
fuel efficiency. popularity expressed
iii more miles to the gallon.
Motor Reliability Sought
The vast improvements in roads.
with hundreds Of thousands Of miles
of improved highways inviting motor
lists to long trips. has resulted in a
call for increased motor reliability
and stamina.
The turn toward enclosed cars has
brought with it an appreciation Of the
finer qualities Of construction. quiet
or operation. but, perhaps Of greatest
Importance, pleasurablc comfort un-
der all weather conditions.
Motor engineers have been asked
to combine economy with power, in it.
self no mean accomplishment.
They have been expected to COM
bine endurance with silence. a prob
lem Of no little import. And they
have turned to the finer builders to
I'D the answer.
Engines More Refined
European builders go in for greater
rcfinements in engine building than
do American engineers. The original
cost of the car. in countries of low
production. does not play the same
part as it does here where we go in
for colossal. production. Many Of the
European cars are hand built.
But the theories and practices Of
the European engineers. worked out
along American production lines. have
taught us a great many important
and interesting things.
In Europe, fuel economy Is an abb
solute necessity with petrol at 70
cents gallon.
All European economy records have.
been established by knight-type mo-
tors. following the small bore. long
stroke design.
Two important reasons for economy
in this type Of motor are inherent in
its design.
There is constant clamor for pow
or among users of cars in this coun-
try. To get power from poppet-
valve type Of motor. the valve areas
must be large. To lift the large
valves requires heavy litter construc-
tion. The result is that there is leak
age Of unburned gases by the valves.
Economy has to suffer If power is to
be obtained. Hence, the noppet-valve
motor ceases to be economical in the
same ratio as it develops power.
Slide by Each Other
With. the knight type motor, the
intake and exhaust operations are
cqHtrolled by the positive actions Of
the sleeves, which slide by each
other
by the position and size Of the ports
in these sleeves. At the moment Of
ignition, the cylinders are completely
"scaled" and there is no opportunity
for leakage. Hence. demands for
power 10 not decrease the opportun-
lty -. economy.
The same valve construction in the
pUppct-valve motor. which precludcs
economy adds to the necessity for
mechanical attention.
The load put on the cam shaft by
the spring tension in the valve
mechanism, the charge in the capac-
ity of the valve springs with the
change in motor heat. the action Of
the exhaust gases on the valve heads.
all contribute to the necessity for
frequent adjustment of the poppet-
valve type of motor if it is to be
kept at anywhere near its best ef-
flciency. This means frequent re-
course to service stations and repair
shops.
The mechanism which actuatcs the
sleeves in the knight type motor
consists Of two small connecting rods,
positively controlled, and with no
Necessity for adjustment.
Silent Operation Demanded
Again. the demands for silent opcr-
altion put in the present day motor
car. are defeated in the poppet-
valve type of motor by the fact that
the entire operation Of this form of
construction requires the incessant
tapping Of metal against metal. The
cam striking against the litter rod.
which in turn strikes against the
valve stem. and the waive head
smashcs down against The metal
valve rest.
Six cylinders, each with two valves.
repeating this operation thousands
OF times a minute. with the valves
netting out of correct mechanical
adjustment. put an impossible task
On the engineer who cndcav0rs 10
Quiet all the noise.
In the Knight type motor there is
no clash of metal. The connecting
rods run in oil, the sleeves slide by
each other with an oil film between
and the whole operation is inner
entity silent.
Virtually all of the present day mo-
tor adjustments and ills are. the di..
rect result of valve operation and
carbon.
The knight type motor Is con
structionally free from any trouble
due to either of these two causes
HEADLIGHTS