ON IGNITION

NZ Truth, Issue 1216, 21 March 1929, Page 19

ON IGNITION

Motorists Have No Trouble Now Now that ignition systems have attained a degree of perfection which cannot easily be increased, it is. interesting to look back to the, early days when matters were very different. . »'. MANY of the pioneer motor-cars : . were "fitted Avith tube ignition— a system . borrowed from, early gasengine practice. Fitted into the Cylinder head was a tube — quite often made of ' platinum — its Outer end closed and surrounded by. a casing lined with asbestos. \ A "blowlamp was used to heat the tube, arid on the compression stroke the mixture, corning Into contact with the interior of the incandescent tube, was fired. Generally, there was no, method by which the moment of ignition could be controlled, so that backfires were frequent. The tank containing the supply of fuel- for the blowlamp was carried, on some cars, behind the front-seat squab. ■'' In this position the pump for keeping up the necessary pressure and the needle valve which controlled the supply of fuel to the burner were fairly; accessible, but fires owing to the blowlamp "lighting back" were rather frequent. A separate burner and tube were, of course, required for each cylinder of the engine, and it was a; problem often to keep the burners alight or to relight them after they had been blown bufc— la very usual trouble. I In spite of the unreliability and general annoyance of tube ignition, however, \ there were many pioneer motorists who regarded any form of electric ignition with the deepest suspicion. - The early magnetos and coils certainly .were very 'troublesome, hut it was not long before improved design and woi'kmanship resulted m their gaining favor, so that existing, tubeignition engines either were scrapped or converted, and no more were built. Most of the early magnetos \yere of the low-tension type arid very cumbersome. They were used m conjunction with a make-and-break working m the cylinder; the "points" were separated at- the correct instant, by an internal cam, and a naming arc was formed m the gap.