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Show Ifr . i High Altitude Effects Motor Vehicles Says Noted Expert Ludlow Clayton Explains ihe Reasons for Trouble With Autos in Various Parts of the Country Where Altitude Is One of Factors fl Speaking In a general sense, a mo-' I tor ought to run hotter at night than I lit the daytime-. Whether it does I haa been matter of '.argument I tween motorists eyer motbrlsts I existed, and one -readily I lulumns of discussion that lasted for: I eara In almost all the early auto-' I mobile mai izlm IJealI thi thing is very almple, Bays I thai engineering authority. . Ludiowl I Clayton, in the current Issue Of Motor ( I Lite. One Is likely to forgot that two H th.ngs are burned In a gasoline motor,1 I gasoline and air Neither can burn H without the other. Also to get the H best and most powerful combustion1 H Ufa proportions of gasoline to :lr can-J H not vary very much To one cylinder H lull of air Just so much gasoline and H no more can be added. 1 To one cylinder lull of air' What Is H a cylinder full? The answer Is that It H nil depends upon what you till It from Everybody knows that when driving in very high altitudes the rarefied air1 H causes a noticeable loss of power; H anyone who has driven at f.OOu feet; H elevation cannot fail to have observed, PISTON" SICKS AIR. 1 Now the real reason for the loss of; power Is that owing to the rarefying, effect of the altitude, the piston can H 01 ly suck in a smaller amount of Mr which will only carry with it a .smaller amount of gasoline and so will only produce a more feeble explosion. Of, course, the volume of air taken in on the suction stroke Is Just the same J whatever the altitude, bill Its weight is less In proportion as the altitude increases and the rutio for best com- B bustlon Is between the weight of the fuel and the weight of the air neees- H sary tu insure- reasonably com I' I B combustion. Other things have the same effect as altitude For Instance, heat rarlfles air by expanding It so that on a hot day the air charge which an engine can breathe In is smaller in weight H than It would be on a cool day In testing airplane engines It is an inva-riu-ble practice to make an allowance fbi the temperature of the atmosphere I because the difference in power is' Quite appreciable. With a 300-horse 1 power engine a variation of fifteen H herse power or more can easily occur ( by reason of nothing elst but change in the air temperature B Here is one of the principal reasons better al night. Night air la almost' always cooler than day air, .so al night' the engine can get a heavier charge and so produce a more powerful Im-pulsi Im-pulsi at each explosion. -Not only is the air taken into the engine cooler and so heavier, but the presence of a cooler atmosphere -means always was noticeably less. In automobile engines It Is unlikely that the water cooling will be more effective, that the motor "will In itself be cooler. This helps to make the charge drawn In still better because the air csmes into the carburetor cooler and Ut heated less on itr. way throuuh the rii r.ifolds ami within th i ylindor n-self. n-self. Also the Oil will be cooler, lis lutrrlcallng properties therefore bet-ter, bet-ter, and so there will be less friction in the motor. DAMPER A 1 11, Yet another th;n- Is that night air orten is damper than day air. The poetic mlats of eventide cool down the i i tor as well as perhaps making the er turn up his coat collar. Haven't noticed how the motometer nek in a rain shower? Well, the f dampness In the air is Just . , same. Not only does the damp help by cooling 6l!ghtl hettcr in what might! bt called burning quality. The best kind of an explosion is obtainable from air that Is not absolutely dty. Damp-i.ess Damp-i.ess In the air within the cylinder makes the explosion less violent The combustion, one might say. Is flowed down ever so little so that the gas gives more of a push and less of a kick to the piston. All thesti thlngn are very small in degree and are limited in range For example, because cold air gives more lower than hot air It does so only so long as it Is not so cold that the gasoline cannot m.x with and vaporize vapor-ize In it pr.Tn 1 1.. Comlnp back to airplane engines agnin. the most power seems to be produced wltii air Somewhere around freezing point, if colder the motor sputters and coughs but let It not bo forgotten that this Is with very high-grade gasoline One can do little more than guess, but the chances an automobile motor Is at Its normal best In an atmosphere around 40 to 60 degreea, PRO ES VRGUMEJ I A British manufacturer of motors was the first to prove conclusively that motors really did run belter a times xther than the middle of the dt.y. He did It by setting up nn en- glne which for some years was run ji.st a half hour or less at 6 In the1 morning at noon, and at 6 In the eve-1 ning.. Averaging all the hundreds of runs he found that there was not much difference between the power mornings and ovenlngs, but that the middny power that all th effects of night air taken together would make a difference of more than ;E per cent, it indeed so much, but this'conld easily represent two or three horse power Dbd perhaps Just make the difference between making some grade on high oi not making It. So when you fanc your car Is running run-ning better In the cool of the evening ou don't have to blamo !t on your Own poeUc state of mind Induced by tiioughts of the Gray's elegiac variety. The chances are the motor reallj Is en-Joying en-Joying the fresh night air. |