The Internal-combustion Engine ...

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Blackie and Son limited, 1923
 

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Seite 147 - In the case of six-cylinder engines, however, it is by no means so easy to do this, and it then becomes desirable to employ vibration dampers or other means to check torsional vibration. The most important consideration to-day is to reduce the rate of wear. This, as shown previously when dealing with lubrication, is a function of the surface hardness, both of the shaft itself and of the bearing material in which it runs. The harder the shaft and the softer the bearing material the better, provided...
Seite 41 - ... the usually accepted theory. (2) That the rate of burning increases very rapidly with slight increase of flame temperature, and that whether it will prove sufficiently rapid to produce detonation or not depends upon the ratio between the rate of evolution of heat by the burning portion of the mixture and the rate of heat loss.
Seite 77 - Further, since all these engines were designed on the same basis having the same valve. opening diagrams, and all running at sufficiently high speeds to eliminate any appreciable variation in the heat losses, the results are directly comparable ; and the deductions to be drawn from them are probably quite reliable. The results of some of these tests are shown in fig. 20, from which it will be seen that, while both the mean pressure and fuel consumption differ very considerably, depending both upon...
Seite 43 - Tizard's researches, that two factors determine whether or not a fuel will detonate: (1) The self-ignition temperature of the fuel/air mixture. (2) The rate of acceleration of burning as the ignition temperature is exceeded.
Seite 106 - If an engine consumes its air efficiently, then it is an efficient engine and to render it economical in fuel is a question solely of carburetion and distribution. If its air consumption is heavy, then no amount of finessing with carburetor adjustments or distribution design will render it efficient.1 FUEL • INJECTION ENGINES 14-29.
Seite 58 - There are three factors in an actual engine which modify the temperature attained by the combustion of a mixture of any given energy content. They are the (1) Heat put into the mixture by compression. (2) Loss due to cooling by the walls of the combustion chamber during combustion. (3) Effective weakening of the mixture due to dilution with the residual exhaust products. Factor (1) is allowed for by laying off the heats of compression for various ratios by the marks "R=5," &c., on the line PPx near...
Seite 170 - Lubrication Systems.— Broadly speaking, the various systems of lubrication may be divided into two classes ; namely, those which supply the needs of lubrication alone and those which make use of the oil both as a lubricant and as a cooling agent. To the former belong all systems of trough or splash lubrication and those in which a small measured quantity of oil is fed to each bearing, while to the . latter belong all those systems in which oil is fed under pressure directly into the bearing itself.
Seite 31 - ... The highest useful compression ratio for, and therefore the power output obtainable from, any petrol is governed by the relative proportions of aromatics, naphthenes, and paraffins it contains — the smaller the proportion of the latter the better from almost every point of view. (12) To judge of the quality of a fuel by its specific gravity is entirely misleading. If naphthene and aromatic fractions are present in any large proportion (as is frequently the case), then a high specific gravity...
Seite 59 - ... ft. Ib. per cub. in. and a compression ratio of 5 to 1, the actual maximum flame temperature, as obtained from the above diagram in fig. 17, allowing for the additional heat of compression, the wall loss during combustion and the dilution by residual exhaust products, will be 2475° C. (4487° F.), corresponding to an energy content of 44-5 ft.
Seite 106 - Where means are available for air measurement, the efficiency of any form of combustion chamber can very readily be determined from the measured air consumption. If an engine consumes its air efficiently, then it is an efficient engine, and to render it economical in fuel is a question solely of carburation and distribution. If its air consumption is heavy, then no amount of finessing with carburettor adjustments or distribution design will render it efficient.

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