El Paso herald. (El Paso, Tex.) 1901-1931, 1914-03-14

3
! line and have been advised to change car
buretor to a StrOmL erg and then could ma ke
II miles to the gallon Do you think TINS
advisable, or to have the Old car hurelor
fixed by the Studebaker company and nave
the defective parts re'lsv ana poSSlpI
would get about u miles TO the gallon+ II
you know Of a carburetOr that would give
me better mileage than the Stro:nEe-g ould
certainly appreciate any advice Thanking
you. am, sincerely WOnsOhn-
Answer-If you are sure you will obtain
such an increase in mileage, 1t viii certain
/ view Of the fact that the old type has not
given satisfaction, it would not be adVis-
able to entail greater expense EXPERIMENT. il5
ing. Considerable progress mas Deen Hlaue
in carburetor construction during the past
two years By effecting the saving in gaso-
line you can soon offest the cost OF new
carburetOr Of modern type
Motoring Department, The Herald have have
of trouble Last December had com
Dlete set Of differential gears installed Yes
terday heard a grinding noise IN the rear
axle. so took same down and round that
three Of the spur gears were broken,
tooth broken off one OF the internal master
gears. and the rest OF the gears were con-
siderably worn The axle was assembled
and aligned properly at the time these gears
were put in Can you suggest what caused
these gears to break and wear quickly
A reply will be appreciated-LeWis Ihomp-
Answer-During 1910 a number Of differ-
ent makes of cars used a spur gear type oif-
ferential. 1t is a known fact that this par
The main reason seems 70 nave 1een ~
the parts were not Of sufficiently liberal size
The little spur gears IN question anu ass
the master gears endure considerable slraln
and should be much heavier Just as soon
as a little play develops these parts are
ground TO pieces. Any back iasa IN tne
drive shaft and universal joints will great
ly augment the trouble and cause very rapid
In view Of the fact that there have been
so many instances Of the kind you mention
it seems reasonable to assume that II these
parts were Of more liberal dimensions Jne
trouble would be eliminated. It IS hardly
possible for you to obtain and install larger
size parts, but you can install the bevel type
differental in place OF the spur gear we;
The bevel type has proved its efficiency anu
durability and while this change may en-
tail considerable lnltlal expense, never t -
less the change would seem advisable rather
than to be replacing the broken parts IN the
old type at such frequent intervals
Motoring Department, The Herald
would be interested to know the advantage
obtained from using an aluminium crank
case I am having made small engine FOR
my own use, and am told that cast iron will
do as we'll I notice that most every auto
mobile engine has an aluminium case Is TINS
better than cast iron? YOU'D ike some IN
formation about this.-Reader.
It is not advisable to use pure aluminium
for a crank case. This would not be strong
enough for the purpose. An alloy containing
s percent copper viii make very strong
case with a tensile strength Of approximate
" 20. 600 pounds per square inch This should
answer your purpose we'll You can also use
manganese bronze which has a greater ten
sile strength but is more expensive A cast
iron case must be very heavy in order to at-
ford the necessary strength In automobile
construction it is necessary 10 eliminate
weight much as possible hence the use
Of aluminium
Would suggest that you use an aluminium
alloy, even at an increase in cost, since this
undoubtedly will prove more satisfactory
for your purpose.
Motoring Department The Herald
would be pleased to have you answer the
, following questions:
inch exerted on the piston head by the eX-
plosion in a gas engine .,..,-..,-
piston is the pressure the greatest?
Third-Does the pressure decrease rap
idly during the stroke OF the piston, or Is
a uniform pressure maintained during the
Fourth-Does a long stroke engine derive
any additional power from the expansion OF
cured.-John P. Meadows.
Answer The maximum pressure within
the combustion chamber ranges from 800 to
$50 pounds per square lncn.
2 The pressure is greatest when the pis-
ton is at the highest point OF compression
| that is to say, when the gases are fully com
| pressed and ignited. As soon as the piston
begins to move downward the pressure de-
g. At the instant heat energy is converted
| into mechanical energy the pressure de-
J creases. The decrease in pressure is, OF
course, very rapid. due to the downward
movement Of the piston as well as OF the
absorption of heat units through the cylinder
walls etc At the time of ignition the pres
sure rises to approximately $50 pounds per
square inch. 1t decreases very rapidly at ap-
prOximately so pounds per square inch.
The long strok motor derives additional
power through the increased thermal ef-
ficiency. This is manifest through the en-
tire stroke. OF course the design of the
motor materially determines the efficiency
Numerous tests have cOnclusiyely proved
that the long stroke motor when properly
designed is considerably more efficient in
power than the short stroke type.
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