“SUN” SERVICE STATION

Sun (Auckland), Volume III, Issue 740, 13 August 1929, Page 6

“SUN” SERVICE STATION

tram ‘Motordom' section 0! Thu Sun mcludea In Its service to readers a Queries and Answers Department. the object or which ls to give accurate lnrormatlon regarding mechnnlcal and touring subjects Whatever the partlculal puzzle may be In either dlagnoslng Irritating troubles. or motoring Information of any kind. "Headllght" will endeavour 'lO help. or refer the palm to men who are recognised automobile experts In their respeqtive lines. All communications must be accornpanlea by the lnqulrer’a name and address (not (or publication). and sent to THE SUN “Service Station. Motordo‘m." THE SUN Auckland. Ans-Wers will appear weakly In this column.

“Workshop.’{—\Yould it be possible to exchange. the tyre covers of a. Chevrolet and a. Chrysler 5: of about the‘ sanm; nxodels?

..- T T No. because the sizes are slightly different. The Chrysler 52 has a cover sized 29 :{’4.75 and the Chevrolet tyre is 30 x 4.50.

“Argument."—\\'e would be glad to 'know the difference between What is Called an ~S.;‘..E. thread on a nut or bolt and .1 “\j’hitwgrth” Ehread.

The S.A.E. thread is the standard measurement of threading adopted by the Society of Automotive Engineers. and is used by all American car manufacturers. The W'liitworth is the standard of all English manufacturers. although a few are adopting the S.A.E. measurement. Roughly, the S.A.E. thread is slightly “rider than the \Vhit—worth; at any rate, wide-enough to render impossible the use of S.A.E. nuts on \Vhitworth bolts, or vice \‘ersa.

Contributor.—“’ill you please explain in your valuable paper what the Cause'uf the following things are in 3. nxotor? “’hat is the reason of the—t batfiery throwing a light fully 50 yards while the: car is standing. and as soon as you get out on the road. the. lights almost go gut. I have just had the battery done up, the: cells well cleaned and acid put in also. I keep plenty

of distilled water in it. Trusting you will be able Lto exglain. _-

If your lights are good when the car is stationary and dim when running, that indicates a bad connection either between the battery and the power fuse, or in the light circuit. You do not say whether you mean the engine is running when the car is stationary. If it is not, and the trouble occum when the engine is running, then’ the trouble is in the generator. either a fuse or in the cut-out. I would be inclined to blame the cut-out. What may happen is that the generator is absorbing power from the battery instead of supplying it with power. This will cause a big expense bill if not repaired at once. The ammeter shouid show you what is happening. If it shows a marked discharge when the lights are on and the engine running. then your cut-out. brushes and coil should be examined at once by a competent electrician.