Motoring Notes

King Country Chronicle, Volume XXIX, Issue 4747, 17 September 1935, Page 7

Motoring Notes

STARTING TROUBLES. Difficult starting on cold morning's is often attributable to a cause to which motorists give too little thought, and the same difficulty repeats itself when the car has been left standing exposed to cold for hours on some parking site. When the car is so parked or is garaged for the night after a run the engine and all its environs under the bonnet are warm and frequently Hot. Petrol is a volatile substance, and under influence of the heat it vapourises. Unfortunately it is the lighter factions that disappear. The starting trouble originates from this vapourising of the petrol in the carburettor. The more volatile and consequently most valuable part of petrol for starting purposes disappears, while the engine and everything about it, including the standing petrol, become stone cold.- Instead of a high-grade volatile substance, occupying the carburrettor the motorist is left a liquid from which the most valuable part has disappeared. As remedial measures the following may be given. In the case of gravity or vacuum feed, the petrol should be turned off overnight and the engine allowed to run until- it stops on account of the carburettor having been emptied as far as possible. When the petrol tap is turned on preparatory to starting in the morning the carburettor will be charged with fresh spirit.

With mechanical, or electric, fuel feed, as a rule, the carburettor cannot be drained overnight, since normally no tap is fitted. A somewhat clumsy but quite effective expedient is to remove the top of the float chamber before attempting to start the engine and decant any petrol residue by means either of a syringe or by soaking it up with a clean rag. A better plan is to have a petrol tap fitted in the pump-to-carburettor pipe. This is turned off when the car is parked or put away in the garage, and allowed to "run itself dry." Such an arrangement need cost only a very few shillings.

FITTING THE GASKET.

REPLACING THE HEAD

COMMON SOURCE OF TROUBLE

Car owners who do their own decarbonising sometimes spoil a good job by the way in which the cylinder head is replaced. Only rarely is it possible to make a satisfactory job by using the old gasket, because this fragile part is usually damaged to some extent when the head is removed. A new gasket should be procured before the engine is dismantled and care should be taken to ensure that it is precisely similar to the one in service. - Sometimes there are minor differences in the positions of stud holes or of the orifices through which the water passes, and so it is impossible to get satisfactory results. The gasket should slide easily over against the flat sux-face of the cylinder block. Be sure that the gasket is put on the right way up. This sounds a simple precaution but it is often overlooked.

In the engines where gasket trouble is frequent it may be a good plan to treat each side of the component with gold size before it is installed. The most common source of trouble is the extremely narrow partition left in some engines between adjacent cylinder bores. The corresponding section of the gasket possesses little strength and unless fully supported by the nipple action of the head and block will blow or burn away, so permitting leakage between one cylinder and the next, in which case it is necessary to take off the head and do the whole job over again.

Gasket troubles are often traceable to distortion caused by uneven tightening' 1 of the cylinder head nuts. These nuts should be pulled up bit by bit, -taking them in sequence as shown in a numbered diagram usually included in the instruction book. This sequence normally consists of working from the ends towards the centre and should be repeated until all the nuts are fully home. After running about 50 miles on the road, during which the engine will become hot, it i-- wise co go over the r.uts again with -a powerful spanner, not forgetting that the right sequence of tightening should be followed. Persistent gasket troubles may indicate a warped head, in which case rectification by experts is necessary.

INVESTIGATE NOISES. WHAT VARIOUS SOUNDS CAN MEAN. Noise from the dynamo of a car is worth investigating promptly. If of a rumbling or pounding variety, it is due usually to slack bearings, and at that stage costs little to rectify. Should it be allowed to continue, however, there is risk of the armature fouling the pole pieces, with serious results. Squeaking arises from the commu-

tator and does no harm. Do not attempt to deal with its lubrication, but have the brushes properly bedded down. This will improve and steady the charging and prevent burning of the commutator.

The method of seating the brushes is to pass a strip of fine glasspaper around the commutator and grind in the brushes on to it to the correct curvature by revolving the armature. This is essential when new brushes are fitted. Similar paper may be held against the commutator when it is revolving to clean it, but if it is badly burnt, pitted, or out of round, it must be removed for facing in a lathe.

Rapid brush wear is due to the mica projecting between the segments or to the commutator needing refacing. The mica should'be undercut slightly below the level of the copper with a piece of hacksaw blade. Use glasspaper afterwards to remove any burring of the copper.

SPARKLETS. "Did the driver of the lorry say anything?" asked the magistrate. "Yes, he said a lot," replied the witness. "What did he say?" "May I leave ' out the swear words?" "You may." "Then he said nothing." The new road that is being built between Cairo and Jerusalem, when finished, will cost £2,000,000. Motorists will be able to make the journey in less than 40 hours. The Israelites took as many years to do the same distance.

A perforated form of number plate which is claimed not to become obliterated by dirt and mud is being tested by the German traffic police. The dirt is supposed to fly through openings in the characters.

Used motor oil can be given in part exchange for new, in Germany, according to a Reuter message. An appeal has been made reminding oil users that economy is necessary owing to the straitened currency situation, and that the used oil can be reclaimed.-

"Women cling to their - youth," says a writer, but they shouldn't do it while he is driving a car.