Arizona republican., 1917-09-16
INSTRUCTION IN
 GRINDING VALVES

Carbon deposits in the internal com hustion engine are like measles in children-inevitable They particular ly afflict the cylinders, the piston heads, the valves and valve seats. The substance is the residuum left from the burning of gasoline and oil. In the beginning the carbon deposits are sim ply in the form of dust, but gradually as oil comes into contact with the car bon and enters the mass, it becomes a cake which is hard enough to require a chisel or similar tool for removal.
 The presence of carbon interferes with the operation of the engine. To begin with, the motor loses it's accus- toned pep and proportion of it's power: overheating may result and misfiring and backfiring are pretty cer- tain to set in sooner or later; the en- zine cannot be throttled down satis- factorily and frequently firing con- tinues after ignition has been shut off; a knocking may develop and the en- zine may not respond readily to the spark advance. All in all the power plant will become sluggish in action, as if it were suffering from Senlle decay.
 So much for the effect of carbon on the body of the engine, but it exercises just as baleful an influence on the ac- tion of the valve system. Here the carbon is deposited on both the valve faces and the seats. Tiny particles of. this hard substance are gradually ground into the metal, until they pre- vent the valves from seating properly. The result is that the fuel escapes from the combustion chamber, com~ pression is seriously lessened and eventually misfiring will result.
 Carbon also is deposited on the spark plug ends in such a way as to cause a short circuit.
 Probably the commonest carbon trouble is from deposits in the cylinder. These deposits consist of small par ticles protruding into the combustion with the heat of the explosion and re- tain their white heat long enough to fire the next incoming charge. The results in just the same metallic knock that comes from advancing the spark lever too far.
 When the combination of lack of power, overheating and knocking oc- CUTS the car owner may be certain that he has case of carboniZation on his hands. In a new car these symp- toms sometimes occur after 300 miles of running, but generally 800 miles is lIt OtSliiliiilS OI lillS liOuOlt Illt DtW car requires an excess of oil, and rich mixture and burning oil is the greatest source of carbon deposits, hence the rapid formation during the early oper- ation of the vehicle. Of course gaso- line also produces carbon. If the mix ture is too rich, much of the gasoline vapor burns instead of exploding and the result is carbon. Obviously then, correct fabrication. not an excess of oil and properly proportioned fuel mixture will do much to prevent car bon deposits. very much more desir- able solution of the problem than re- moving them afterward
 Within recent months there have been placed upon the market num- Der of devices generally called steam injectors, which introduce live steam from the cooling system into the fuel vapor. These are claimed to remove carbon from the cylinders and prevent its ever forming again. We doubt the ability to remove carbon already formed, but the introduction of steam into the combustion chamber does cause any carbon formed to enter into a chemical combination with the gases of the explosion and leave nothing in the chamber.
 Now as to the removal of carbon de- posits already formed. There are a number of methods of doing this work;