The Brookings register. [volume] (Brookings, Brookings County, S.D.) 1903-1971, 1916-12-07

What final ratio is considered best on
cars with 80 by 4 inch tires. and what
speed should be obtained from this
ratio2
The size Of the tires is not the oil
important factor in determining the
proper gear ratio. ms there are many
other points TO be considered, such as
the most efficient speed of the motor,
the weight of the car, etc. These may
so alter the proper gear ratio that the
mere size Of the tires becomes insig-
niticant In determining the final re-
duction. With this in view, 1t is i'm
possible to state that any. given final
reduction Is best for a given tire size.
| have changed the 80 by 3 inch front
wheels and tires or my car to 80 by 3Ia
in order to have the same size all
around. How much more than a mile
will have to travel before the speed
ometer registers one mile2
Unless YOU have replaced the entire
wheels you should not have changed
your 30 by 3 for 80 by 312, as the rim
profile for a 80 by 3 tire Is different
from that of n 80 by 3a. In changing
your equipment from 80 by 3 to 80 by
3D. ON the same wheel il would be nee
cSsary TO cut the felloc of the wheel
one-half inch all the way aroun and
buy II new rim OF different profile.
Without changing either the wheel or
the rim you can use a 81 by 3h tire, In
which case the distance travelled by
the car would be 1888 per cent greater
than the spcedometer reading would
show. If you change the wheels and
rims and use the 80 by 3L2 size In place
Of the 30 by 3 your speedometer read
ing would not be affected.
What is the setting Of a magnetic on
racing cars in seneralf
In general, the timing for a racing
motor Is advanced from one to two
teeth on the timing gears ahead OF
touring practice. The exact number Of
degrees OF advance will depend upon
the make OF magnetic, and hence no
definite rule can be laid down for this,
but where It is common touring prac-
tice to have the full retard occur on
upper center in II racing motor, the
full retard position will be advanced
one or two teeth on the timing gears.
Can you give me a formula for a So
luton to be used in soldering aluminium
as muriatic acid is with sheet ROM
The luX generally used with alumni
mum IS chloride Of zinc, but with the
solder yon speak Of this might not
prove to be the best.
Where is the best place for the spark
plug in any type of engine?
The best place in the combustion
space for Il spark plug Is at the point
Of purest mixture. This will vary with
different types OF motor, owing to the
differences in shape In the combustion
chambers. The reason for this is that
where the charge is less diluted by
~unscavengcd gases 1t win burn quick
est and surcst.
Some engines stop almost immedi-
ately after the switch is cut off, while
other engines seem to lose their mo-
mentum gradually. Why is this?
When the switch is cut off on an en-
CINE il is merely a matter OF bringing
to rest the moving parts which are no
longer propelled by the explosion of
the gases in the combustion chamber.
Only one influence is probably great
enough TO be considered as the Oppos-
ing factor 10 the movement of the mo-
tor, and this is the internal friction.
When this has eXertcd its influence to
such an extent that the motor Is un-
able to turn itself over against the com-
preston of the cylinders 1t will come
to rest. The compression IS not an OPP
posing factor unless the momentum Is
insufficient to carry the motor over top
center, because when il Is carried over
top center the expansion Of the ON
pressed air gives up practically all the
power which was utilized In compress
ing II. If the compression were used
before the engine will be unable to
turn itself over the dead point. With
these considerations it will be easily
seen that Il motor with tight bearings.
tight piston rings and high compression
will come to rest much quicker h
one which has the opposite conditions.
What factors determine proper valve
dimensions?
The method for determining the
proper size of the valve depends upon
the gas velocity through the valve and
the piston speed. Gas velocities are
calculated on the basis of piston speed
and a full opening Of the valve.
When an inflated tire is in a station
airy position at which point is the high
est PRESSURE?
The pressure Is the same throughout
the tire. 1t Is n Of the fundamental
physical properties Of gases that when
a mass Of gas Is inclosed In a vessel 1t
exerts a uniform pressure against ev-
cry square inch Of the surface Of the