“MY RACING EXPERIENCE.”

Southland Times, Issue 20538, 14 July 1928, Page 5 (Supplement)

“MY RACING EXPERIENCE.”

LECTURE BY CAPTAIN MALCOLM CAMPBELL. Captain Campbell—the famous English racing motorist—in a lecture recently given to the motor trade at Manchester, England, took for his subject, "My motor racing experiences.” He set out to show (a) how racing improves the motor industry and (b) how it improves the breed. He referred to his twenty-two years' interest in speed work and to the progress of the records from 126 m.p.h. on a Benz car in 1914 and the post-war figures from K. Lee Guinness up to the latest achievements. Up to 1924, he remarked, nobody could tell whether beaded-edge or straight-side tyres were better. Both crept round the rim on acceleration. Deciding on the former tyres with an ample number of security bolts, he did 145 m.p.h. in Denmark, and two back tyres came off. “The car swayed, but we managed to control it.” Therefore, straightside tyres with security bolts were fitted on the rear and beaded-edge on the front. One of the latter came off and killed a boy. The lesson of it all was that beaded-edge tyres were a thing of the past, useless for high speeds. “It shows racing does help to bring improvements,” said Captain Campbell. After describing various other record-breaking runs, the speaker said: “I never seem to hold the record for very long.” The lecturer described his record attempt in America. At 180 m.p.h. he met a bump on the sand, causing the car to leap and jump 30 feet. It was lucky the car did not break in half and that the springs held; but it made the springs soggy. "We broke all our shock-absorber brackets and cracked the body. But I have a wonderful set of mechanics. On Sunday, February 19, we got the record.” As to the sensations at high speed, he declared: “There is no exhilaration. The actual feeling of speed at 220 m.p.h. is not as you sitting here may visualize it.” He declared the big job was to keep the car straight for 5i miles, and told how his wrists ached on the return run after a bump on the outward stretch. “I had an awful job to get into second; I had to take my foot off the accelerator twice on the return run.” Hence the speed then was 199, against 214.7 outward, or an average of 206.95. He described White’s six-ton car (the American car which now holds the world’s speed record of 207.55 m.p.h.) as a means of trying to get records by brute force; but in generous terms he referred to the sportsmanship of his American rivals, and told how the late lamented Lockhart just lived for his job. Racing improved the industry, he declared, helping British goods to grip foreign trade, and, incidentally, developed international goodfellowship. He spoke highly of modern tyres as being now in front of the speed, whereas formerly it was the reverse.” SOME CAUSES OF FIRE. LEAKAGE OF PETROL. AND THE VAGRANT SPARK. A frequent cause of fire is the leaking of the carburettor of the pipes leading to it. Sometimes a union in the petrol supply pipe between the tank tap and the carburettor is troublesome. It may not leak badly, but when the car is parked or garaged there will accumulate a layer of petrol-impregnat-ed air, which is explosive and if ignited may set fire to the petrol in the float. Some of these leaks are hard to find. It takes considerable time to locate them, since the petrol vaporates almost as rapidly as it leaks out and the surface may seem dry. But the inflammable gas is being made, and is dangerous. A badly seating float chamber needle valve is a very frequent cause of petrol leaks which may be dangerous. When the engine is running this is not so serious, as the petrol may be drawn fast enough to prevent flooding. But when the engine is at rest the float chamber will overflow and the results may be dangerous. This petrol-impregnated air may be ignited by a spark. Even the spark which may occur at the contact-breaker of the magneto or of the coil and accumulator system may cause a flare-up if the air is carrying petrol fumes. This may often occur after the car has been at rest with the engine stopped, and on the first attempt to start the motor. In the case of the garage the same conditions arise. The car left standing should have the petrol turned off. It is a good plan in the case of pressure feed petrol tanks—where the petrol is under pressure from a pump as in many cases—to release the pressure when leaving the car for any time in the garage. These pressure tanks are almost invariably below the level of the carburettor, hence the need for a pressure above the fuel to lift it to the carburettor LOSS OF TUNE. FINDING THE CAUSE. REMEDIES EXPLAINED. A car engine is a complex piece of mechanism, and though reliability now is its outstanding characteristic, it is apt to develop faults after some thousands of miles’ running has removed its original “tune.” This is particularly the case when maintenance work has been neglected. Loss of “tune” is made noticeable by various signs, chiefly loss of power and acceleration, and when they appear a driver almost always suspects the carburetter is the cause of the trouble. Frequently, however, such is not the case, and in attempting the cure an owner may do a good deal of harm to a piece of mechanism which is innocent of defect. Faults in diagnosis arise mainly because most engine troubles show symptoms which superficially appear as carburetter faults. Yet beyond the periodical cleaning of jets and filters, little can go wrong with the modern carburetter. Almost certainly after giving lengthy trouble-free service it will not suddenly alter and cause trouble. For example, if a car has averaged, say, 25 m.p.g., for a period of months, and suddenly fuel consumption increases to 18 m.p.g., a first cause might be carburetter flooding, or fuel leaking in the piping. Both faults are visible ones, and accompanied by the .‘fnell of escaping petrol. If an inspection fails to reveal them, then the cause of the sudden excess consumption must be sought elsewhere. The most common cause is a faulty plug, probably one that only “misses” at intervals. Next come gummy, or stuck valves, while the other main causes are binding brakes and insufficient lubricant in the back axle, or gear-box. A faulty plug is easily replaceable, but a gummed or stuck valve may cause an owner to rush his car to a garage for an engine "take down.” Gumming usually reveals itself by backfiring, or popping, through the carburetter, and mis-firing. The most effective remedy is to squirt paraffin through the valve spring on to the stuck valve while the engine is idling. The trouble also may be cured by allowing drops of oil—preferably a high flash point oil—to drop into the air aperture of the carburetter and be sucked into the engine. Again, both popping back and missing are causable by a too weak valve spring, which should be replaced, and by an induction leak. The leak usually is remedied by screwing up the nuts holding the manifolding to the cylinders, or by fitting a new manfold gasket. In these days of over-silent cars, few motorists appreciate how the blocking of the exit apertures within the silencing "box” can adversely effect engine running and increase consumption. The fault, however, occurs frequently, and the symptoms usually appear as if the supply has failed. Further, it will be found that the engine seldom will run for long at more than half-throttle without backfiring. The remedy is to dismantle the silencer and clean out the carbon deposits.