Benzoic and How to Use It.*
Page 8
If you've noticed an error in this article please click here to report it so we can fix it.
Points to Aid Users who are Desirous to Make Tests.
Some General Remarks.
llenzole is a colourless, volatile and highly inflammable liquid of the hydrocarbon series. In appearance it is very similar to petrol, but chemically there is considerable difference, and it can be divided into various series, e.g., paraffin, olefines and benzines. Speaking generally, the majority of benzoles are mixtures of the three series mentioned in varying proportions, and they are obtained either by extraction from coal gas, or by recovery from the distillation of tar.
The various processes and plants in use are numerous, and can be divided into high and low tem
perature .distillation processes. Temperatures approximating to 2000 degrees Fahr. are employed in the former, while in the low temperature series they range from 580 degrees Fahr. to 950 degrees or 1000 degrees Fahr.
The amount of benzole recovered byThigh temperature processes varies from 21 to 3; gallons per ton of
coal coked. In low temperature distillation the quantities are very largely increased.
Benzole as a Motor Fuel.
It is essential that good quality spirit only should be used. An unwashed or insufficiently washed spirit cannot prove successful. If in appearance the spirit is of water-white colour it is probably of good quality. A yellowish appearance suggests caution, although under certain circumstances it may be quite suitable. The only safe way to prove whether a spirit be suitable or unsuitable is by means of a chemical test which indicates the extent of the presence of coumarine.
Coumarine is a dark, sticky, oily-looking substance, which, if present in the spirit, deposits itself on the valve stems near the heads, trickles down into the guides, and after a time "gums up" the valves, prevents their prompt return to their seats under spring pressure and so renders the engine inefficient. A. properly-washed spirit has the harmful proportion of colunarine removed and can be used with complete success. The Petrol Substitutes Joint Committee is giving close attention to this question of washing.
How to Use Benzole.
With the majority of carburetters benzole may be used equally as well as petrol. When first using it, do not alter the carburetter. After about a 20-mile run, notice if there is any sign of extra heating about the engine generally, or if the exhaust gases are extra hot. If extra heat is observed, adjustment of the carburetter is needed. In carrying out any adjustment of this nature, although somewhat paradoxical, it is a practical truism that benzole gives better results on the less-benzole-to-the-same-air idea than it does on the same amount of spirit with more air. This is an argument therefore for reduction of jet orifice.
After a run of about 50 miles, remove, say, a plug in one of the front cylinders and a valve cap in one of the rear ones. If there is anything in the nature of a sooty deposit, reduce the size of jet orifice. At the end of the next 100 miles do the same and so on until such time as the right proportion has been obtained, and the car runs without any deposit of soot at all. These successive jet reductions should be very slight.
The Question of Exhaust Gas and Sulphur.
Should the exhaust be malodourous, i.e., to a greater degree than with petrol, and the smell be sulphurous, it. argues in the direction of too high a
sulphur content in the spirit. The committee is at present conducting experiments to determine the maximum amount of sulphur than can 'be permitted without producing unsatisfactory results, and although the tests are not yet completed, it would seem that anything up to 250 or even 300 grains of sulphur per gallon of spirit may be allowed, without a inalodourous exhaust being produced, or any chemical action being caused on the metals in the engine.
The Solvent Attributes *I Benzoic.
As benzole is a stronger solvent than petrol, temporary troubles my be caused by paint (from the inside of the tank), small pieces of rubber, etc., which were inocuous in petrol being carried into the jet by benzole. If such troubles should occur, fill the tank with benzole overnight, and empty it in the morning, through a strainer. Particular care should be taken not. to spill benzole on the coachwork of cars, as it may attack the paint or varnish.
No Engine-knocking and Its Lesson.
Another feature is that the use of benzole will stop knocking in practically all cases where engines are inclined to knock on petrol. The motorist, therofore, must bear this fact in mind and not "hang on" unduly to the top gear on hills just because he notices that the engine does not knock, otherwise excessive strain is being put upon the bearings, gudgeon pins, etc.
High Compression.
The use of benzoic permits of higher compression
without causing pre-ignition or knocking. This point, perhaps, is of more intrinsic worth in connection with cars intended for racing purposes than for the ordinary motorist.
Extra Air.
The prevalent idea that an extra air valve is needed with benzoic is not correct. With the older type of carburetter, an extra air inlet may prove advantageous, but it is preferable to go on the lines of jet, reduction with the same air inlet than to try to use the same quantity of spirit with additional air.
In addition to reducing the size of jet orifice, it is also desirable to raise the level of the spirit in the jet in order that it will flow more easily, thereby facilitating efficient carburation. This can be done in a number of ways, one of the simplest being to atl.i to the weight of the float by putting a little solder on the top. In doing this, care should be taken to add the solder in such a manner as not to interfere with the efficient working of the toggles.
With many carburetters, heating of the induction pipe also adds to the efficiency of the carburation, and if desired, this can be done easily by adding a small auxiliary pipe from the circulating system in such a manner that the induction pipe is encircled.
More Power and Mileage.
From 12 per cent. to 15 per cent. more power is obtainable when using benzole, and an increase of something in the nature of .20 per cent, more mileage per gallon. This latter fact should be borne in mind in regard to the question of price. Really good benzole commands a fairly good price at present, and undoubtedly there are a large number of benzoles obtainable at the moment on the open market which are superior to peticl. If, after trying ben. zole and attending to the points enumerated in these notes, the motorist does not get good results, then it is time to put a query through to sallIC authority on the subject and try and find out the reason