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Additives can eliminate smoke
Page 72
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THE DEVELOPMENT of smoke-depressant additives is described as the most significant development in fuel technology over the past five years in a paper, "Developments in Lubricants and Fuels", recently presented at a meeting of the Institute of Road Transport Engineers by Mr. W. A. Patrick of Lubrizol (GB) Ltd.
Mr. Patrick said the results of engine bench tests, covering a wide variety of engine types, had confirmed that an average smoke level reduction of between 20 and 40 Hartridge units could be obtained for engines with smoke levels ranging between 40 and 80 units.
Judged by visual rating methods, he said, this represented a range from "visible but acceptable" to "objectionable"; in all but the worst cases a reduction of 20/40 units would eliminate smoke as a public nuisance.
Smoke-depressant additives also extended injection-system overhaul life, improved internal engine cleanliness, provided better fuel stability and reduced fuel-system corrosion. Because the optimum injection timing for minimum exhaust smoke increased fuel consumption by as much as 4 per cent, the use of a smoke depressant would permit an engine to be tuned to give minimum consumption and still maintain an acceptable smoke level under all conditions.