“SUN” SERVICE STATION

Sun (Auckland), Volume II, Issue 550, 31 December 1928, Page 6

“SUN” SERVICE STATION

'li t] Motordom” section of Th« Sun includes in its service to renders a. -*- Queries and Answers Department, the object or which is to give accurate information regarding mechanlcaJ and touring subjects. Whatever the particular puzzle may be in either diagnosing irritating troubles, or motoring information of any hind, -Headlight*' will endeavour to help, or refer the point to men who are recognised automobile experts in their respective lines. Ali communications must be accompanied by the Inquirer's name and address (not tor publication), and sent to THE SUN "Service Station, Motor, dom.” THE SUN. Auckland. Answers wili appear weekly in this columu.

“Wiring.”—l notice that the ammeter of my car seems to show a discharge when the lights are on and the engine charging the battery. Until recently it showed a slight charge at this point. I have looked over the generator and that seems all right, so I wondered if it was possible that the current might be leaking by contact of a wire with the chassis. The car has a “double pole” system. Could you tell me if the current could earth if the insulation had worn off one of the wires by rubbing on the chassis?

Current cannot escape, or, in other words, a short cannot occur in a “double pole” system, unless both wires are bared and contacting with the frame. This only happens in a single pole system. Still, if there are any bare or worn spots on your wiring, take a roll of insulating tape to them immediately, or you will strike trouble. The cause of the ammeter’s reading cannot be as you suggest. I would

advise more research in the generator. The commutator may be dirty, or the brushes worn, stuck or not seating properly.

F.S.—My 1926 model Chevrolet car engine gets very hot after a mile's run. The oil boils. In fact, I can touch nothing it is that hot. I keep water and oil extra clean and engine well lubricated.

It appears that you are troubled with overheating, and being a 1926 model car, which would probably have run 20,000 miles by now, I suggest that you check the following points: Has the radiator been drained and flushed out regularly every two months? Is the water circulation correct? Is the ignition timed correctly ? _ When were the valves last ground in. and is there any carbon deposit? Lastly, is the mixture correct? In my opinion the trouble is probably due to the circulation of the water. As you are probably aware, the Chevrolet is one of the coolest engines on the road, and it is very hard without examining the car to decide just what is the actual cause of the trouble. 1 suggest that if you are able to obtain the loan of another radiator core from a friend, and run the car for a few miles, it will prove if the trouble is in the core. If the trouble is not overcome by the change over of core, of course, the other items mentioned above should be checked over. N.A.R—My car is a 1925-6 model Hudson, and once when tuning I was “revving" it up rather highly (in neutral) and at a certain period it gave vent to a weird squeal, which seemed to come from the generator or clutch. It occurs at a definite period, for in second gear it occurs at 25 m.p.h., and resembles the noise made by engaging the starter when the engine is running. It ceases if throttled down to 34 m.p.h. A friend also has a Hudson (an earlier model), and it howls too. Since it occurs in neutral, it is not the gearbox, which I have lately oiled, and since it occurs at a definite period only It is not lack of oil. My friend and I would be very grateful to any reader who can solve the puzzle—we can't! The squeal is probably caused bv lack of lubrication at the top of the pistons when the motor is revving fairly hard, as it is at 35 m.p.h. in second gear. I have had cars with similar complaints in my care, and have traced the troubles to dry pisby , a Process of elimination. Tpper cylinder lubrication is a suggested remedy. To test the effeft of this pour a quantity of oil into mo U .or VaC a Um taDk ’ and then rev the ™isappeared° U th *