The Twin City star. [volume] (Minneapolis, Minn.) 1910-19??, 1915-05-08

How oan ono tell whom magnetic
needs rsmasnetizins?
When the magnets will not lift and
hold about fifteen pounds they are
said to be weak. Missing fire at low
speeds is the result Of weak magnets.
w. this occurs the magnets should
be recharged.
What arc tho respective advantages
and disadvantages Of the 7 head and
L head types of notors7
The T head motor, because its valves
are located on opposite sides, allows of
the use of large valves, and hence more
power is obtainable than in the L head
variety, other things, of course, being
equal It Is usually more costly to con-
struct than the L head type and has a
more symmetrical appearance. The
T head, however, is heavier and more
complicated than the L head design,
the latter using only one cam shaft and
having the valves all on one side.
What are tho advantages and dis
advantages Of tho valve in the head
motor7
The chief advantage claimed for the
valve in the head motor is that, for q
given size, it has more power than an
L head or T head, because Of the fact
that larger valves may be used and
the combustion chamber given a more
spherical shape. There are number
Of manufacturing advantages, one of
which is that the entire combustion
chamber may be machined and given
high polish, thus preventing, to a great
extent, the accumulation Of carbon.
The loss Of heat through the cylin-
der walls Of motor depends to great
extent upon the surface Of the walls,
and In a properly designed valve In the
head motor this wall area Is small,
compared with that of another type of
motor Of the same size. This reduc-
ton Of wall area is obtained because
Of the absence Of valve pockets
The main disadvantage of the valve
in the head motor, especially one using
valve cages, is that the valve seats can
not be cooled as effectively as If the
seat were part of the casting. This
is true in the cage construction, be-
cause the heat, In order to get from
the valve seat to the water Jacket.
must overcome the resistance Of the
joint between the cage and the cylin-
der casting. This lack of cooling would
not materially affect the inlet valves,
as they are kept comparatively cool by
the incoming gas, but it would mean
more valve grinding In the case of the
exhaust valves.
10 II possible to maintain pressure In
. rear fuel tank whom the tank cap 10
mIssing7
In cases Of this sort take an old in
ner tube, cut out piece about eight or
ten inches long, tie one end tightly, 50
as to be air tight, then insert the tied
end into the tank. Next remove the
valve connection from the pump, in.
sert the hose in the open end Of the
tube and pump until the tube com
pletely fills the hole In the tank. Then
tie the outer end securely. This con
trivance will hold several pounds pres
sure in the tank and will last for some
time.
Is three sishths Of an inch too much
play in the wrist pin bushins7
Three-eighths of an inch is entirely
too much play for the wrist pin bush
ing. assuming that up and down play
Is meant There should be 80 little
play that it cannot be felt by move
ment of the wrist pin.
Can ! siIverizs glass rsfiectors7 II
90, what are the ingredisnts and In
what proportions are they used7
An amateur can silverize refectors,
but it is very difficult to make a good
job Of It. The method by which this
work has been carried out is as fol-
lows: First fasten to a block Of wood
the finest possible grade Of emery
cloth. With this the reflector is
smoothed down to a fine finish 1t is
hCAl uCSCccdiy " udfo q hcitluB put
and a thermometer which is capable
Of measuring more than PIP degrees.
Two ounces Of lead, two ounces of tin
and four ounces Of chemically pure
bismuth are melted together Eight
ounces Of mercury are added at PIP
degrees F. and mixed with the melted
mixture. This is applied while warm
with q smooth camels hair brush.
Which will give the better results,
go or ~ test gasoIins7
As between 60 and "a test gasoline.
the 60 test fuel has been found to give
the best results as far as mileage Is
concerned. The gasoline which we get
nowadays Is much heavier than that
on the market, say, FIVE or ten years
ago.
Can an expert gain any advantage
by changing from automatic to hand
control in a battery ignition system7
A skilled driver might get better re-
suits with a hand control of the
spark than could be obtained with
the automatic type Of ignition control
for the reason that grade climbing can
be accomplished much easier and the
loads of the motor considered. In 9th
er words, the driver can shift his