1930-06-07 — Page 14

THE HONGKONG TELEGRAPH, MOTORING SUPPLEMENT.

DESTROYING OBSOLETE MOTOR

CARS.

One hundred and sixty condemned automobiles were stacked up in a pile at Long Beach. Calif., and at night were set afire.

USEFUL HINTS.

But retarding the spark will not a similar knock, for they may cure the trouble. If there is an strike the shoulder in the cylinder accumulation of carbon in tho at the top or hattom and produce How to Detect Trouble.cylinder head, it should be scraped sharp knock at each turn of the Dut Carbon causes preheating motor. It is therefore advisable and detonation, which in turu to have the cylinders rebored and

pistons and brings on the clink-clink of the fover-size

rings engine.

VARIOUS NOISES.

[By Israel Klein.]

A clink, a rattle, a siap, a thud and the ear of the experienced driver can tell where to look for the source of auch noise. The sound, however it may come, is generally termed a knock, but an engine knock varies with cause.

installed.

If the ignition is timed too If a piston ring happens to early, or is caused by a sticking break or become loose, it will automatic spark advance, the same cause a light rattle, keeping up steadily and repeating about twice sort of knock will result.

to every revolution of the motor

= * 22

If a lighter rattle is heard from| the engine, the cause may be an improperly adjusted timing chain. But this occurs when the engine

rods. the is idling and not at a pull, as in the case of a carbon or ignition Wherever two parta move knock. If the timing chain is too against each other, there is a tight, however, it will produce a source for a knock if they fail to steady ham at all speeds. work together properly. They Sometimes worn timing gears may be too tight, or they may be loose. If they are not fitted just right, they'll cause a noise that has been referred to as a knock. are too tight, they also will cause; The heavy thud may be the Know each knock and you'll be a steady hum or grinding noise result of loose engine support able to tell the mechanic imme-at all speeds.

bolts. This makes the entire diately what might be the cause

engine vibrate and might cause of your engine trouble,

Whether a piston is loose or considerable damage unless the tight, it will cause a knock in the bolts are tightened immediately. Perhaps the

common form of a slapping noise. This sagino knock is the clinking, noise is noticeable most on acce-

The heavier sort of knock, almost like a thud, may be traced to the main bearings or to misat connecting

The heavy knock may not be noticed at idling speed but will begin its thud-thud as soon as the engine starts to pull. The same sort of thud may be heard when the will cause a slight rattling noise crankshaft is out of true, and this at idling speed or at about 30 comes out particularly at a pull miles an hour. And If the gears, and at low speed.

most

1

*

*

common knock is the

SATURDAY, JUNE 7, 1930,

WATER FOR THE STARTLING FACTS.

RADIATORS. Impurities Which Harm Cooling Systems.

RAINWATER. GOOD.

Cost of Motoring

At Home.

TAX PILED ON TAX.

We are pleased to see that the Motor Agents Association in follow. ing up the good work it performed last year by tasuing leaflets getting out the startling facts concerning excessive motor taxation.

The water which is generally Available in England for use in radiators can be divided into three classes rainwater, soft tap water and hard tap water. The iron of which the cylinder jackets are made is unprotected, and thereupon burden fore becomes rusty very quickly, no matter what kind of water is employed, but other phenomena occur which are influenced by the impurities which the water con- tains.

There are very many factors

the affecting

efficiency of a motorcar engine, of which the cooling system Is only. one,

The object in view is to induce Nevertheless, it is extremely im- all motorists to write to their mem- portant that the cooling system ber of Parliament setting forth should be adequate to cope with their views on the subject. The the great heat evolved by the leaflet sets out the following facts: burning mixture which wouldThat the motorist in this coun- otherwise damage the working try is now paying an average tax parta and make cylinder lubrica-per vehicle five times as high tion impossible. A primary re- as that imposed in the United quirement is that the surface with States. That the average tax per which the "water is in contact vehicle in 1920 was £14; in 1925. should be kept, as far as possible. £19 and in 1930 £27. The yield in clean and free from scale. these three years shows the follow- Whether or not this can be met ing increases: In 1920, £4,970.- depends to a large degree upon 000; in 1925, £16,485,000; and in the water habitually used.

1930, approximately $41,000,000. For the current year the petrol tax will cost the motorist £16,000,000, and since it was imposed in April, 1928, the motoring community have These figures show how burden paid £26,612,000.

is piled upon the shoulders of road transport, and an effort to bring individual members to realize that motorists firmly be lieve that the limit has been reach- ed and that they are entitled to re- lief is surely worth while. Deputa tions and memoranda apparently have little effect. The motorist must himself get in touch with his member, state the facts and tell him what he thinks about the excessive burdens he is called upon to bear.

Exchange.

Two processes of rusting pro- ceed on the internal surfaces of the cylinder jackets, one being simple corrosion, due to moisture, carbon dioxide, and free oxygen; this produces a uniform surface of rust. The other is local corro- sion, due to galvanic action which produces pitting.

WELL SUPPLIED.

From the 1929 automobile reg-

If pure iron be immersed in "pure" distilled water no trouble of any kind occurs, but these con- ditions are never obtained in prac- istration figures of Canada it is tice. Distilled water has a found that that country is the greater solvent effect on metals second largest motor transport- than, water containing certain using land in the world. The ratio ear for every nine salts in solution, and may attack there is one copper parts of the radiator, de- persons. positing the copper on the iron jackets in the form of green spots around which a galvanic action and pitting will occur. This action would only be slight, and with distilled water there would

cooling.

USE MUCH RUBBER.

Eighty-five per cent of the rub-

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COME AND INSPECT THEM.

ratling sound that reveals carbon leration or a pull, or on changing clicking sound that comes from be no incrustation to impede ber production in the United THE SINCERE Co., Ltd.,

or ignition trouble. It is heard from high to low gear. In means, the valves. It may be due to too mostly when the engine is pulling of course,

up hill or under any other load. Leylinders.

pistons Worn

and much clearance between tappet and valve, or to worn valve faces, It can be softened, or eliminated, Installing new oversize piston or worn valve lifter rollers or pins. for the time being by retarding rings in such a case may not help If the valve guide is loose it will the spark.

at all. In fact, these may cause click each time the valve is lifted,

Speed

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Stamina

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(New Reclamation)

Tel. 20406.

Causes of Galvanic Action-

however, other There are, causes of galvanic action; thus, contains impurities, the iron irregularly distributed, such as manganese and sulphur. Between spots. rich in such impurities and adjacent portions of iron of differ- ing composition u galvanic couple is set up, resulting in rapid corro- sion. Uneven incrustation may also be a cause of intense local galvanic action,

At the other end of the scale there is hard, calcareous tap water, containing calcium-car- bonate, both salts being held in solution by carbonic acid. Calcium-sulphate is often also present, and the crust deposited on the walls under the normal temperature conditions which obtain in an engine is hard, dense and cohering. As it is a bad con- ductor of heat it impedes cooling to a marked degree.

In addition to the above car. bonates held in solution water ofen contains small quantities of the sulphates, chloridea and nitrates.

Characteristics of Rainwater.

Rainwater collected artificially is a typical soft water containing little mineral matter.. Streams. running through districts devoid of vegetation have very nearly the same characteristics. As a rule, however, they dissolve peaty. matter on their way, owing to the absence of salts. (Hard waters will not dissolve the calcium salts of vegetable acids). Peaty water contains díssólved oxygen, and its 'action on metals is enhanced by any oxide formed, so that it may render corrosion. somewhat serious.

+

Rainwater collected as cleanly as possible offers to the motorist a not unhappy via media. Even in districts suffering from bad atmospheric conditions the water. is tolerably pure, particularly when the rain has been falling for some time.

A water yielding a heavy scale is thoroughly objectionable, but one which produces a slight film is not entirely, harmful, as the film may actually serve to provide some protection from corrosion from other sources. It is interesting to note that a new car obtained from the Midlands will have been tested and run in with water that"pro- duces such a film in a short space of time,

and if the valve springs are broken or weak, the same clicking rattle will result.

This sound may start with a tap-tap and end in a pronounced clicking. The valves should be corrected before they come to the click.

States is consumed by the motor vehicle and tyre manufacturers, according to the U. S. Department of Commerce.

SOLE AGENTS.

TRUST A THORNYCROFT WITH YOUR Transport

DEAL DIRECT.

THORNYCROFT

SIX-CYLINDERED

COACHES & OMNIBUSES

MOTOR VEHICLES

Pioneer Manufacturers of Commercial Motor Vehicles

4 or 6 Wheels

4 or 6 Cylinders

30 Cwt. to 10 Ton LoadsTM

20 to 70 Passengers

JOHN L THORNYCROFT & CO., LIMITED

UNION BUILDING...

.HONGKONG

FIFTH FLOOR.

Write us and our representative will call.

Telephone 24881.

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