MOTOR NOTES FOR MEDICAL MEN
H. M. Buist
BMJ (Clinical Research Edition)
HOW TO READ THE SCOTTIsH TRIAL RESULTS. WHILE tlle Royal Scottish Automobile Club, like the Royal Automobile Club, is unable to create what might be called new fasllious in cars, nevertheless by recent enterprise both organizations are helping to pave the way to the production of velicles tlhat will sulit thbe needs of owner-drivers in particular hotter tllani tlhoee hiitlherto available. Tllus even in' tlle case of th0e Manx motor racina' for the Tourist T'roplhy and for the " i Fifteen
... " Trophv, which is really one of the final plhases of experimental work, very valuable progress has been made under tlhree Ileadings, among manv otlhers-namely, in the direction of the evolution and use of mixed fuels with power alcolhol as au essential ingredient; in the evolution of brakes to all four wlheels; and in tlle demonstration of the fact"th at thee coided typ'e of tyre makes for amazing durability aiid economy auid 'will presently be available, witiout undue weiglht, on the straight-sidcd principle with liglht rim. The thixed-fu'el proposals will-interest medical men in very ricLLilt fas1mion -at no distant date, for some of our lCrgiest lucldlistributing p'ganizations lhave already completed prans or,9engaging in tlhe business on a commercial scale. Thie mixed -fuels are, evolved in mneasure as tle, liquid-fuel iatern-al-comblstion' engine is developed. THE COM1ING OF MIXEIn FUELS. If tca standardl car tril in Scotlaud, or the special racing ca"s rtin in tle Isle of Man, or, more particularlv, those which will be raced for the Grand Prix on the Strasbot;rg circuit in the middle of tllis mointlh, be examined, it will be found that tlle' greatest progress 'is beinig made in the direction of producing more powerfromii smaller engines. Thllis is made possibo by bthe use of comlpression ratios far higher tlian tlose formierly employdcl. For exam-ple, when the war broke out a 51 'to 1 compression ratio was considered almBost too hiiglh even for aircraft engines; wlhereas tlle Vauxlhall cams raced in the Isle of Man hnad compression ratios of about 7 to 1, and several cat s that will figure on tlle Strasbourg circuit will lhave at least tlhat. One result is that we are getting 90 h.p. out of a 2,OOOc.cm. eDgine, or what we slhculd call approximately a 14-h.p. type Tmrasury ratinig. But tlhese powers, wlich are capable of propelling chassis 'tit extraotdinarily ligh speeds, are being de!v'1oped -With an amazin"g fuel economy, particularly if we east our minds back -to -the days wlhen we were racing with engines of ten times the-volume that figured in the "Fifteen Hunidred T. T.," the carlier vehicles achieving only 60 per cemit. of speed on aneasy course and uEder better weather conditions than obtained in ttie Isle of Man last mith' whien the miniature etngined vehicles were raced. In other words, a glance' at tlle story of racing reveals plainly that we bave beeil r3ducing car weiglht, increasing reiability. and reducing-tlhe eng,inie space in relation to the clhasss s ,aee, as well as. the fuel -ail tyre consumption in relation to the work done. -Special bi-fuel carburettors are ready for standardizatioe; and' the motorist will have the opportunity of choosing eitler -to develop greater-lhorse-power or to save 25 per cenit. of' -is fuel bitl and develop as much power as at prcsent, or toco6mbite paets -of the two gains. '---; , I '3ut at present, thoughl-th-e straiugt-sided tyres certainly make for economy under the most severe test of all-namely, racing, wvlereinthe wheels lhave to be bkidded rouund ;the eornersand-tlle side str-ains are tlherefore at tl e maximum, nevertheless tlhe weialgt of the detaclhable rims is at present atn ob jection 'to tlheir immediate universal use. Information of whlichl I am Fosscssed,-liowever, leaves me no manner of oubt tlhat this particular weiglht problem will be sclved t no distant date. FuLrther, the risk of tlle detachable rim ruasting 'in 8iIt is likely to be elimin-ated by tlle materials that will vbo .emlployed. Already: it is possible with the co-deddtyre on the beaded-rim principle to obtain anaverage of two and a lhalf times the tyre mileage that was possible witlh canvas tread tyres. -When it slhall become possible to use a straihlit-sided tyre without extra weight and without any possibility of the rim rusting, tyre mileage'will be increase still more. Thus already we 'have reached the point at wlAcli tyre costs are lower than they 'wer6before tthe .war -if we put tllem on the only possible scientific basisnamely, cost per car mile. POINTS ABOUT SMALL CARS. In the recent trial of standardised small cars by tlle Roya;1 Scottish Automobile Club, the awards in coninexion with which were published in these columns last week, i is interestina to note tlhat, thouglh under the heading of tyre trouble each competitor was allowed sixty minutes during tlhe wlhole week in the course of 1,020 miles running witlioht being penalized, only one competitor of the forty-four'who started exceeded tlhat allowance, and thlat by a nmargin of three minutes only. Firom this the conclusion might be drawn that these cars are adequately tyred as a class. But I tlinuk it would be an erroneous one. At least, the impression Igat1hered myself when watching some of the hiill-climbing work in the Highlands was that' there is a tendency by the trade to under-tyre small cars as a class. Curiously, in tlhe otlher extreme there is a tendency in some of thie middle-class cars to over-tyre. -One useful result of tlle Scottisli trials will, I think, be to cause some of the leading makers of small cars to fit larger tyresnext year. BLat as long as we use tlle beaded-edge type of tyre, which. i3 likely to be with us for another season or two in the majority of cases, there is no question that it is necessary to lhave proportionately somewhat larger tyres, botlh for comfoyt. in riding and as to the air space, to ensure the neceissary strengtll. Vast improvements have been made in the corded tyre, and I gained another impression in Scotland conccrning tyres for small cars. I am quite su-e some of the competitors strove to save tlleir springs in what wvas certainly a punishliing test-many of tlle road surfaces were of an extrenely irregular character-at the expense of their pneumatiwby running them somewhat slacker than the tyre makers spoeify. This is a foolislh policy and is bound to lead to trouble. No car owner should ever slacken lhis tyres with a v-iew to saving hlis sprinas; it is sure to result in nipping, ripping, or otlherwise destroying the tubes, while the wrong sort of play occurs to tlle walls, particularly when corners are takcn; therefore thetreads get worn out untimely. -THIS YEAR-AND NEXT. In face of the very great proportion of hill climbing tliat had to be done in the course of the tour and of the fact that some of the ascents over which tlle competitors were not timed were of more severe gradient than those over which they were it means a deal for tlhese little cars to average 20 miles an lhour from point to point. Indeed, I have in mind one particular hill climb, not in the timed area, along, the descent following wlhich we were r.ding in a big 6-cylinder car at from 10 to 12 miles an hour only because tLe.back axle was crashing against the side members of the car framo every now and again the moment we went any faster" so irregular was the surface of tlle mouLntain road. Tlle drivor of this non-competing, lightly laden car tried to sootlhe our anxiety wlhen we hinted that we mi(glht be getting hiome somewhat late by sayina that it was impossible th14,:the small cars could go as fast as we over that route. I roinited out, however, tlhat ancording to their showing they would keep up the schedule, tlhoughi, admittedly, on some of tlle steeper ascents they could not average 20 miles an hiour on tlhe climb; therefore their only chiance of keeping to schledule wvas to go over the ground we were traversing at 10 to 12 miles an hour t 25 or 35 milcs an hout-. That is precisely whlat they did, it being quite remarkable hlow closely-these little vehicles kept to schedule. I saw: them come in at the end of that day's run, as on other nights. Quite 80 per cent. of the competitors -came in within a minute of their schedule time on 'a day's run of aniytlhing from 160 to 180 miles. The tests slqowed clearlv that these little vehicles can be built to stand rattling over bad roads. Furtlher, tlle club's methibd of examining the cats that appeared to do best in the Trials -at the end of the test, to make -sure that they eallywere 'in good condition before granting awards, is a wvise move, and makes such awards of additional value. Some would urge that tlhe trials should bs extended.c.xt year -to embrace vehic!es 'witlh engincs up t' 2,000 c.cmn. 0olume,-instead of setting the limit at 1,600 c.cm. as-tllis year, b4ut that woald be a mistake. There is no particular need to try thicies as large as 2,000 c.cm. enigine'volum-ein -tests of this sort next year. Tllere will be forthcoming 'then qjuite-as many-1,600 c.cm. vehicles as even the Royal S4tislm Athe Bomobile Club iOf could hand!e because many membWs. of te riti, and'1European, indusltry who abstained this year have suddenly recognized the value of wlhit is the-imost scien-.