The Twin City star. [volume] (Minneapolis, Minn.) 1910-19??, 1915-05-22

How oan one tell when q magnetic
needs rsmagnetizing7
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 are the respective advantage
and Disadvantages Of the T head and
L head types Of motors7
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
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 the valve In the head
motor7
The chief advantage claimed for the
valve In the head motor Is that, for
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 q more
spherical shape. There are a 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 or 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 itspossibIs to maintain pressure In
rear fuel tank when the tank cap 10
snissing7
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 eighths Of an inch too much
play in the wrist pin bushing?
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 so little
play that it cannot be felt by a move
ment Of the wrist pin.
Can ! silverize glass reflectors? II
80, what are the ingredients and In
what proportions are they used7
An amateur can silverize reflectors,
but 1t is very difficult to make a good
job Of 1t. The method by which this
work has been carried out Is as fol-
lows: First fasten to block Of wood
the finest possible grade Of emery
cloth. With this the reflector is
smoothed down to a fine finish. 1t is
next necessary to have a melting pot
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 camel's hair brush.
Which will give the better results,
go or ~ test gasoline?
As between 60 and IA 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 battery ignition system?
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
loadseof the motor considered. In 9th
er words. the driver can shift his