“SUN” SERVICE STATION

Sun (Auckland), Volume II, Issue 468, 25 September 1928, Page 6

“SUN” SERVICE STATION

fT*HE “Motor dom" section of The Sun Includes in its service to readers a Queries and Answers Department, the object of which is to give accurate information regarding mechanical and touring subjects. Whatever the particular puzzle may be in either diagnosing irritating troubles, or motoring information of any kind, “Headlight'* will endeavour to help, or refer the point to men who are recognised automobile experts in their respective lines. All communications must be accompanied by the Inquirer's name and address (not for publication), and sent to THE SUN “Service Station, Motardom," THE SUN. Auckland. Answers will appear weekly in this column.

J.C.—Would you kindly let me know through the medium of your Motor Column what is the trouble wih my car, an Essex coach (1928 model). (1) Th© car bumps and jerks in high gear at low speeds, even at 14 m.p.h., and the engine misses. I had the valves ground and cleaned two weeks ago. (2) I lifted the bonnet in the darkness one evening while the engine was idling, and all the wiring and plugs were firing or shorting like a fireworks display. I raced the engine a little and the firing disappeared.

(1) Your carburettor needs adjusting, and would suggest cleaning the inside thoroughly with ordinary brass polish. (2) Apparently rain had got in through the louvres of the bonnet and soaked the wires. When the engine had been running a little the heat generated dried everything. In wet weather it would be a good idea to line the inside of the bonnet with felt or old linoleum. F.F.—What is the maximum speed of a 1926 4-cylinder Willy s-Knight Sedan? * * * About 65 m.p.h. J.M.O’L.—Can you tell me why my 1926 Cowley, after a run of 17 miles, heats up to such an extent that you can barely put your hand on the radiator? Car was purchased new, anci has only done 7,000 miles, has lately been decarbonised, valves were ground in at 5,500, everything else working O.K-, and oil quite fresh; still she heats up very quickly. Any of the following items may cause the trouble you are experiencing:—Clutch slipping, brakes binding, fan-belt slipping, valve timing incorrect, oil pump not functioning correctly, insufficient oil in sump, oil of the wrong grade, ignition timing too late, engine requires decarbonising., valves not seating correctly, carburretter out of adjustment, radiator tubes or water jackets choked with foreign matter. All these points should be checked.

You do not state whether the radiator actually boils. If this is not happening, you have no reason to worry, as with a thermo-syphon cooled engine the radiator water has to heat to approximately 200 deg. before it starts to circulate correctly.

J.L.C.—When trying to find the reason why my car has been running badly, and hard to start, I found that the valves seem quite loose on the valve guides. I believe that air leaking in through the guides would cause the trouble I have had. Could you tell me if this is so, and how I can stop the trouble?

I experienced the same trouble with an old Overland with exposed tappetts. I remedied same by fitting a fairly thick, tight-fitting felt washer on the valve stem. This washer was held in place by the valve spring, and when soaked with oil helps to* lubricate the valve stem and guides- I feel sure this will cure your complaint.

J.M.D. —My ear seeds to be decarbonised. I have been told that it is possible to have this done without taking the cylinder head off. Which is

the best way to do it? Can a satisfactory job be done without removing the head? * * * The method of removing carbon by oxygen flame is probably what you mean, and it is not much used now, since detachable heads are standard. When used by an expert, it used to be quite a success with the old-fash-ioned plug-ports which were sunk in the head; but I do not think it could be managed through the small plugholes. Peroxide mixed with the petrol will remove carbon from the top of the pistons, but neither of these methods takes the carbon out of the valve ports or piston ring grooves. Anyhow, the valves will want grinding, too, so it is best to take the head off and get everything done at once.

L.O. —I would be greatly obliged if someone could give me information concerning trouble I have been having with my car. The car, a 1927 Overland Whippet, 96 model, has done 6,000 miles without any trouble, and now is only doing 30 miles, or even less. I lose up to six pints of water. The engine and top of radiator get very hot. A new gasket has been replaced, but of no avail. All tire waterways have, been gone over. It has been kept in a wonderfully clean state, also the fan and pump are working 0.K., as numerous engineers have decided on that point. I . can leave car over a week and no loss of water occurs, but it heats up, and a great quantity is lost through overflow pipe in starting. Could it be that a correct circulation is not occurring, and the lower part of radiator is the cause? I would indeed be greatly obliged for some advice on the matter.

The cooling system of the Overland Whippet is very efficient, and the only likely way in which overheating or loss of water will occur, if no external leaks are apparent, is through the compression leaking into the water jacket, and blowing water out of the radiator. This would be due to either a cracked cylinder block or head, or a leaking gasket.