MOTOR NOTES.

Hutt News, Volume 3, Issue 13, 21 August 1930, Page 4

MOTOR NOTES.

A PRACTICAL JOKE

An amusing practical* joke was play-, ed on the owner of a sports ear near Brooklands recently. The perpetrators • securedj,three bloaters which they concealed and -wired) under 'the exhaust manifold. The unsuspecting owner started up nad xii-oeeeded on his way, followed by the perpetrators'in another ■ cai\ As the engine warmed up to its work so the blbaters commenced' to" cook. The sports car uaiver, however, continued on his way undaunted, much to the surprise of those following, who were regaling themselves on the smell floating astern. Eventually both cars camo. to rest and-surprise turned t<3 consternation, when it was discovered that the sports car driver had attributed a faint smell to "a new -gra&e of oil he was trying out. vj . COLOURED TYRES It is cabled from London that tyres coloured to match motor ear bodies are the latest novelty in. JEngland. Birmingham dye experts ha^e, it is stated, devised shades of blue, green maroon, and yellow for tyres, which will withstand the "severest road tests. It is hoped that the innovation will make 1931 models ! even more attractive than those now used. Coloured covers have already been extensively usexl in Australia. In 1916 ana 1917 the standard Dunlop motor tyres made and sold in that country were white, whilst- iii 1918' the red tread ,'*.' Railroad^' cover was introduced anjj popular deinanci right up to the introduction of the balloon type of tyre dn 1924. The colour of these cover? was of course, introduced when compounding the rubber, and the colour was permanent. .The English suggestion obviously does; not apply to this method of inanu: facfiiring coloured tyres, but evidently refers to colour impregnation of the sur-. ''face-of:'the outside of the cover by dye after'its ; ! construction, somewhat aft.-r the method" of applying the spo/ial' tyre j paints niarketpd to-dayV "With the Use of penetrating (lyes the eolnur would, no doubt be m6re 'pf'irnaiient. Further de- . tails of the Birmingham i^xpoviments will be awaited by-many motorists' with interest. .:' ■ : MILEAGE PER GALLON The majority of drivers have not a very comprehensive knowledge of the more technical parts of the car, and consequently are content as long as the car continues to perform satisfactorily. When driving -faults have been corrected there still remain' a large number' of adjustments to-be done, and some of these are beyond tjie^.average driver. The slight expense incurred in having them done would be more, than covered by-the infproved performnjice. !There are however, some adjustments^tvhieh can easily be carried out by the ; veriest novice and among these the most outstanding is the correct inflation" of the • tyres. If the tyres v are not correctly inflated it takes more power to propel the ear, and in consequence naore petrol is ' used), while the tyres also wear much faster. Again, binding brakes consume power, while a poorly tuned engine cannot give - its ; maximum efficiency if tappets, valves and springs are not functioning at their best. Man motorists to-day are not obtain- , ing the maximum miles per gallon, that

their ear ' is--capable- of-for the simple reason that the carburettor is not adjusted *foi^ (economical running. Slight L alterations in choke and jets can. effect ■ surprising reductions in petrol consumption, without any sacrificing of engine efficiency. Wheel alignment is one of the most expensive defects that motor cars are heir to, and if tyre wear is irregular or" unduly pronounced, steps should be taken at once to see. if the trouble is not attributable to this cause. There, are many other minor factors that effect power output,' but sufficient have been, cited to bring under the "■ notice of motorists ceftain methods of increasing their mileage per gallon and thus avoid the extra cost of petrol by increasing the efficiency of th«ir ©ar. • AIR-TESTING THE ENGINE One of .the newest tests for pisboh ' rings ■ involves, the use of ; air - 'unaer: pressure. A special plug is inserted into each cylinder in:"' turn and a tyre air hose attached to a suitable coupling. The amount of leakage by the rings can be determined bjr the amount of oil mist that rises from the oil filler pipe. It is necessary /<yl}en making +h« test to place 'the bar in gear, otherwise tli>i air will start to "run" the^engine. This would upset calculations, since movement of the pistons would escape. The method can be used- to test valvesj since escape of air through intake or exhaust when the piston is at upper dead centre indientes that they do not seat properly.