AIR ESSENTIAL.

Press, Volume LXVIII, Issue 20510, 1 April 1932, Page 6

AIR ESSENTIAL.

EFFICIENCY OF PETROL ENGINES. If a petrol engine could breathe more air into its iron lungs greater automobile efficiency could be obtained, according to Charles D. Hawley, an American expert. Air. he says, is the limiting factor in automobile and aeroplane engine power development. "Many people think that the amount of power generated by an automobile engine is due entirely to petrol," Mr Hawley explains, "but air is just as essential. It is easy enough to inject more petrol into the engine, but increasing the amount of air taken in at high speeds is quite difficulty Approximately 1200 cubic feet, or about 901b of air. are taken into the engine for every gallon of petrol consumed. " Both air and petrol are chemicals. The first is composed of about 20 per oeiit. oxygen, 79 per cent, nitrogen, and a small percentage of other gases. Petrol is composed of compounds of carbon and hydrogen. It is the oxygen content that makes air necessary in a petrol engine.'.' SAFETY FACTORS. CARS PAY FOR CARE. Although more safety factors are added to automobiles each year by the manufacturers, they are pointing out that these are no guarantee against the neglect by car owners, which often result in grief. Among the causes of misfortune emphasised arc operating motors in closed garages; failure to check batteries at least once a month; and omitting to grease cars every thousand miles run. Many radiators have been ruined when cold water was ponied into them while they were excessively hot, and oiling systems become clogged because the filter cartridge has not been renewed each 10,000 miles. Draining and thoroughly flushing the entire cooling system twice a year will add life to the motor, and an inspection of the ignition system in the fall and spring will reveal any' wear which may lead to trouble. Most defects which develop in automobiles are the result of Jack of proper care, the makers Say, rather than any inferiority in materials, since these' are all rigidly inspected before they arc put into the vehicles. SLUGGISH STARTER. GETTING BEST RESULTS. Sluggish action of the starting motor is not a sign that the expensive battery needs renewal. Those with some knowledge of electrical theory will realise that a six-volt starting system must be free from resistances caused by poor contacts if the necessary starting current of more than 100 amperes is to flow through the motor. Battery contacts often suffer, owing to the creeping action of the acid, and it may he necessary to fit new terminals on the cables, which is quite a cheap ioh. The terminal posts of the battery should be scraped bright and coated with heavy oil, while the cable terminals are smothered with vaseline before replacing. After the car has bad a couple, of years of the frame terminal should be removed, and both the terminal and the portion of the frame against which it is boHrr] should bo 'polished with emery cloth and slightly smeared with vaseline before roplncin'si. Tighten up all switch and motor terminals. Inspect die commutator of the startin": motor, reached "by removing the thin metal band damned around it. If oily, clean it with petrol. Tf the coin'mutator anneai's to be burnt or pitted, "csuo'-iiillv if (bo hiii-niii? is patebv. it should be overhauled by an expert. During the twelve months ended 'September 30th, 1031. the number ot private ears registered in England tor the first time was 1-11,12.52. compared with 153,459 in. 1930, a decrease of 12,207.