REMEDY FOR PRE-IGNITION

Shannon News, 10 February 1928, Page 4

REMEDY FOR PRE-IGNITION

u Pro-ignition is, of course, due to ■ ' Some part of the combustion chamber having been so hot. that it is t . actually incandescent. A small part of metal heats up more quickly than a large one, and consequently it . is usually a plug point or some particle of -caibon deposit which is causing the trouble.' The remedy is simple. In the first case a now plug of the correct type should be litted, and in the second the engine should bo dccar . bonised. The use of aluminium' pistons has done much to remove pro ignition, for aluminium conducts the ' heat away very quickly. Noverthc less, there are many engines, which largely owing .to inattention, pre ignite after a burst of full throttle and. the pro-ignition is not always re cognised. It may be very slight; if so, practically the only symptom .Is loss of power. On the other hand, it may be severe, when tho engine will feel as if there were actually a brake upon it. An engine should never be driven against pre-ignition, for this is what, happens. On a certain throttle ‘ opening pre-ignition is causing a loss of, say, 25 per cent- power. To con-tinue-at the same speed, therefore. , the throttle must be opened farther, which will make the engine hotter and the pre-ignition worse, until eventual ly a seizure may take place.