Pine Bluff daily graphic., 1915-05-09

needs rennaaretizing?
 When the magnets will not lift anc hold about fifteen bounds they are said to be weak Missing fire at low speeds is the result of weak magnets. When this occurs Ihe magnets should be recharged
 What are t..e respective advantages and disadvantages of the T head and L head types of motors?
 The T head motor. because its valves Are located on opposite sides. allows of the use of large valves, and hence more power is obtainabe 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 the advantages and dis advantages of the valve in the head motor?
 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 number of manufacturing advantages. one of which is that the entire combustion chamber may be machined and given q high polish. thus preventing, to great extent, the accumulation of carbon.
 The loss of heat through the cylin der walls of d motor depends to great extent upon the surface of the walls. and in properly designed valve in the heud motor this wall area is small. compared with that of another type of motor of the same size. This reduc- tion of wall area is obtained because of the absence of valve pockets.
 The main disadvantage of the valEe 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 ill 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.
 Is it possible to maintain pressure in rear fuel tank when the tank cap is missing? ~ a'"
 In cases of this sort take an old in ner tube, cut out Il piece about eight or ten inches long, tie one end tightly, so 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 ill the tank and will last for some time.
 Is three -eiehths of an inch too much play in the wrist pin pushing?
 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 move. ment of the wrist pin.
 Can ] silverize glass refIectors? # so, what are the ingredients and in what proportions are they used?
 An amateur can silverize refectors but it is very difficult to make 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. It is next necessary to have q 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 212 degrees F. and mixed with the melted mixture. This is applied while warm with smooth camers hair brush.
 Which will give the better results, 50 or "A test gasoline?
 As between 60 and 74 test gasoline. the GO 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 systeSa?
 A skilled driver might get better re- suits with 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 tr H. AL ;