MOTOR AND CYCLE.

Taranaki Daily News, Volume LVII, Issue 113, 6 October 1914, Page 7

MOTOR AND CYCLE.

ALL TUB WORLD OVER,

T(ie following is from a £ome_joitfi ml.—.A reader complains iliftv ,f ' lc t place* lu'd hand against the air i .of his carburetter when the engine W : running he feels that "a ivet spray" is ! being blown back, and he asks if 'this j* ■ 'responsible for the veny. high petrol i .consumption of his machine, and if so, I 'vhat ig the remedy. There is always , l'« certain amount of "Mow-back" in an inlot valve; while the .inlet valve is cpen, tine mixture is surging engineiwarda at furious velocity, and, when the inlet Talve shuts,, the tail of the procession of gases, so to speak, i 6, brought up with a jerk and surges back, upon itself; with a short inlctt pipe, this rebound must be' ' perceptible at the air intake. If the blow-back is excessively damp, Uk carburetter is probably failing to vaporise the petrol efficiently, with a good modern canburetter, the rebound is perceptible, but docs not feel "wot" and should not stain a sheet of clean Wotting paper kid over the air intake. It is further possible that a weak explosion ia taking .place while the inlet valve is open, which may be due to pie-ignition or to a false magneto timing. Year by year, as the motor-cycle becomes, more handy and reliable, so it is used to a greater extent by business men. It is surprising, however, that more travellers do not make use of the motor-cycle or sido-car machine. Miuch time can be saved if it is necessary- to make eross-coumtry runs*, as the majority of travellers and doctoral do, an.l tbexe is little doubt that, even if the | motor-cycle is no cheaper than the train —which matter has never really been settled—the user's independence enables j him to cover far more ground than he

■would otherwise be able, to do, and- thus, ;n the long run, gain considerably. It has often surprised us that more manufacturers do not make a greater appeal to travellers. A company which really took the trouible to produce a machine with ideal mudguards, and an arrangement of footboards which would somewhat resemble the undershirt] of ; i c»r, and which went out of its way to demonstrate to fousiriesa meiv the cleanliness of their production, would reap an enormous harvest. A most interesting consumption test with various kinds of fuel was recently carried out in England. Petrol, benzol, methylated spirit and a half-and-half mixture of benzol and methylated epirit were "tried out" on a 20 h.p. fourcylinder car, and gave most interesting it-suits. The figures obtained can be accepted as being reliable and practical for the affair was under the supervision of the Royal Automobile Club (London), and the materials, were 'bought retail in the ordinary way immediately prior to the test. The comparativei tcBults from petrol and benzol did not differ in any degree from those previously published on mkiny other occa'siona. Petrol was shown to be slightly less economical than benzol, but yielded a slightly greater maximum power and Bjeed, while methylated spirit -was very much less economical, tat improves proportionately on; its admixture with benzol. At twenty miles per hour on Brooklanda the relative consumptions were: Petrol '35, benzol 40'/,, and methylated

spirit 23% mi'cs per gallon. At bhirtyfivo miles per honir the figures were I BO'/a. 31-'4, and U% miles per gallon respectively. With equal parts alcohol l"and benzol 32"/ 2 miles per gallon was the ! consumption at twenty miles per hour, ; And 25% at thirty-five miles i)>er hour. Bo far nothing very remarkable lias to jhe noted beyond the extravagance of | alcohol. But when the car was let loose under open throttle to register its maximum speed the results were 43'/ t 'miles per hour with petrol, 40% with methylated spirits, and 40'/o with a mixture of equal parts benzol and alcohol. I Here it 'will he seen, all differences be- | tween benzol and nKithylated spirit I practically vanish, while the advantage |.!of petrol over alcohol in less than 5 per cent. As the zenith carburetter used was separately adjusted for each fuel, Ibenzol having a smaller jet,, and alcohol a larger one than for petrol, it may be that, the adjustment favored methylated spirits; or it may be that tho timing of the engine was more correct, for the I I glower rale of combustion in alcohol. Without some such explanation the phenomenon is eurio-i.-. We know that 'alcohol requires a much higher ratio of compression than petrol or benzol to develop its highest efficiency. In this instance it was unaltered at 4.3 for all. jjand it may be that suvh a ratio was more favorable for alcohol than for the other fuels, fuch an assumption, howI ever, will nob be. accepted by the experts, who, therefore, are left to exI plain the puzzle. Otherwise it would be I logical to suggest that if the engine compression were increased alcohol would actually show a superiority: in power over b«nzol. and even over petrol too. This has not yet been claimed for it, bo we must await the analysis of those results, which will elucidate the riddK Messr s Laccv and Co. have the lara-mal-.i agency 'for the famous Darracn -motor cars! The firm have just landed! a 1014 Olegg model do luxe, and the machine is one that will bear close inspection. It is lfl-h.p., beautifully sprung and balanced, and the painting is of and right tint for summer. The lighting is 12 volt C.A.V. set and the h°odis easily manipulated by one man. Toe : cut created a great impression at Hie Olvmpia Motor Exhibition, and altogether is a machine well adapted for Taranaki work. The gears number four and are splendidly adjusted, the steepest hill lieing easily negotiated on lop gear. The ear has tho further advantage of running almost sikntlr. Messrs Spedding, Ltd., announce in another column that they have just imported direct a very large stock ot motor-cycle tyres, the prices of which they claim to be the lowest m the district. In addition to the tyres they have a large stock of other accessories.