EVOLUTION OF PETROL

Press, Volume LXX, Issue 21329, 23 November 1934, Page 19

EVOLUTION OF PETROL

♦ ELIMINATING "KNOCK" POWERS OF ETHYL DEMONSTRATED The evolution and powers of super .Plume ethyl petrol were described and demonstrated to a meeting of 30 representatives of motoring interests conducted by the Vacuum Oil Company, Pty., Ltd., in the Chamber of Commerce Hall last evening. An interesting address on the evolution of petrol and the elimination of the "knock" to increase speed was given by Mr J. E. Batchelor, chief fuel engineer to the company in New Zealand. ~ , The story of super Plume ethyl was largely the story of the modern motorcar, Mr Batchelor said. Contrasting present-day cars with the earliest cars, there was a great difference to be noted, and the fuel which suited the earliest engines could not be expected to be suitable for the modern vehicles. Engines were increased in size with the object of getting greater speed, and at one stage they grew too big to be covered with bonnets. It was found that it was possible to reduce, the size and weight of material by using different materials. These included alloying steel with several rare metals, by which lighter parts could be made, and the use of aluminium had also been discovered. More power I could be put into the back wheels from a smaller motor. Seeking Greater Speed One of the most important advances lay in the increase of the compression ratio to give greater speed. This had been followed-right from the start, and far greater speeds had been developed. Various stumbling blocks had been overcome, probably the biggest of which was the fuel. In a single drop of petrol there might be scores of hydro-carbons, each of which had a differing boiling point, and this had caused difficulties. The Ethyl Corporation was originally formed as a merger of petrol and motor interests. General Motors, Ltd., was one of the biggest shareholders. The refiners had done their part in improving fuels, but the Ethyl Corporation was formed with the object of eliminating the petrol "knock which occurred when the compression ration was reduced. The corporation started on a research programme to eliminate the knock, and during investigation tests about 33,000 substances which were soluble in petrol were tried. About 30 were selected which had an effect in the combustion of the fuel. A knock in an engine was no more than an extremely rapid burning of the fuel. There was nothing really mechanical about it at all. No Corrosion Of the 30 substances referred to one was found that controlled the combustion of the petrol and prevented it from reaching the stage at which the knock occurred. Experiments were made with engines, and it was found that this substance caused corrosion. Complaints had been made that ethyl was corrosive, but these had been wrongly based on a little knowledge of one stage of the research. Ethyl fluid could not be fairly judged by the results reached before it was marketed. It was impossible to get corrosion from ethyl petrol as used today. Mr Batchelor demonstrated with an engine especially designed to prove the value of ethyl. He showed that the ethyl fluid controlled detonation and eliminated the knock, at the same time increasing speed.