“SUN” SERVICE STATION

Sun (Auckland), Volume IV, Issue 1006, 24 June 1930, Page 6

“SUN” SERVICE STATION

THE ’Motordoin' section ol The 6’ti Queries and Answers Departmei accurate Information regarding meclu ever the particular puzzle may be In or motoring information of any kind, refer the point to men who are rec respective lines. All communications must be acoc address (not for publication), and s Motordom” THB SUN Auckland.

Constant Reader. —Would you kindly supply me with the following information: (1) Is there any difference in the timing of valves on the English, American and Continental cars? (2) Could you inform me where I could obtain an instruction book for the 3926 Majola car, and if there is an agency ip Sydney or Melbourne?

(1) Yes; valve timing varies in most cars, depending upon design of the motor, number of cylinders, peak revolutions, volumetric efficiency and similar factors. (2) There is not an agent for Majola cars in Australia. J.W. —Could you enlighten me on the most probable cause of one (only) big end of connecting rod burning out. It is a Fiat 509 car, and has been running well until it suddenly developed a knock, and on taking the engine down I found that No. 3 connecting rod bearing bad burned out. T realise that it is useless to re-run it without finding the cause, hence my inquiry. Overhaul tlie lubricating system. It may have ceased to supply oil to the bearings, in which case the failure of one big end would have been followed by more serious trouble. If the system is functioning properly, the failure of a single big end points to a choking of tlie hole through which the oil reaches the oil channels in tlie bear- “ Overland.,” —(1) I have an Overland car, 192 6 model, fitted with a Stewart vacuum tank, and lately when running up a steep hill in top gear it develops a rattling noise. It also happens on the level if the accelerator is pressed right down. I have definitely traced the noise to the tank, as the same noise occurs if the car is shaken when stationary with engine stopped I have removed tlie p’ug at the bottom and about a pint of petrol flows out. I have also cleaned the strainer at the

m includes to Its service to readers a nt, the object of which ts to give anlcaJ and touring subjects. Whati either diagnosing Irritating troubles “Headlight* will endeavour to help, or cognised automobile experts in their

irnpanied oy the inquirer's name arid sent to THE SUN “Service Station, Answers will appear weekly in this

top. Would it be necessary to dismantle the tank? (2) Does the generator or starter need any attention on this make of car?

(1) I do not think the rattle complained of has anything to do with the interior of the vacuum tank, but probably is caused by the bolts or brackets holding the vacuum tank to the dash, a loose petrol pipe in dash clips, or a top

rear bonnet clip vibrating when extra strain is applied to pull over a bill. The float in the vacuum tank could develop a slight tapping noise, caused by the guide pin of the float tapping against the guide brush, but only being noticeable when the engine is stopped and the car rocked. The vacuum tank at all times will be found to contain approximately one pint of petrol. To test if the trouble is caused by the mechanism of the vacuum tank so as to enable to test on valve assembly by removing the pipe unions together with eight metal screws leaving sufficient petrol in the vacuum ank so as to enable to test on a bill, taking care that the vacuum tank end of the suction pipe is temporarily blocked up, so as not to cause an air leak. (2) The Autolfte generator and selfstarter do not generally require any attention beyond oiling occasionally "with very light sewing machine oil. M.R. —I have on my Rover 9. a Lucas generator which has stopped charging. I have looked over this unit, but am unable to find the fault. With the engine running and closing the cutout in the switch-box, there is an 8 amp. discharge, but on releasing cutout, it will not charge in. I have checked all connections and fuse, which seem O.K. When the generator first gavd trouble, the amp. meter would waver and not charge in readily. I would be obliged if you would advise me. If the commutator is clean and bright, the trouble is probab v in the brushes or in the wiring of the generator. The discharge when you close the cut-out merely shows that the power output of the generator is not sufficiently strong to overcome the desire of the power in the battery to earth itself. If the brushes are not worn and have good bearing surfaces, possibly the brush holders are clogged by oil and dust, and will not allow the brushes to fall into position on the commutator. Examine these, and try a variation of the position of the third brush. If the trouble is not i ■ have Hie coils examined by an expert.