1928-04-07 — Page 13

THE HONGKONG TELEGRAPH. MOTORING SUPPLEMENT, SATURDAY, APRIL 7, 1928.

OLDSMOBILE | HINTS.

SIX

RODUCT OF GENERAL MOTOR

111-inch Wheelbase-19.84 H.P. (R.A.C. Rating)— 185 cubic inches piston displacement-1928, models.

Dickey-seat Roadster

4-seater

G.$1,175

Touring Car .......

.5-acater

1,175

Sedan (2-door)

b-geater

1,250

Sedan (4-door)

.6-seater

1,350

FOR THE

MOTORIST

by

ALBERT L, CLOUGH

A

་་་

OPENING AND CLOSING

OF VALVES.

AN EXPLANATION OF OPERATIONS GIVEN.

[By Frederick C. Guerrlich.) Many people, even auto mechanics, are of the impression that the Inlet valve of the engine opens the moment the piston la at the top of its stroke ready to go down on the suction stroke' and. closes immediately upon complet- ing. this stroke; that is, that it opens on top dead centre and closes on bottom dead centre.. This is not the case.

Too Close Valvo Adjustment. fens unduly when exposed to cold Too loose valve adjustment-o or to oil in which some water has Probably the pump much space or clearance between collected. the ends of the valve-stems and keeps filled for a time, but oll, re those of the push-rods while it in- turns so slowly through the fine

The usual practice is to have the volves clicking nolae and, if meshes of the strainer that, after inlet valve open slightly after the

reduction excessive, some

in a time, the all level falls below the piston and, therefore, crank pin much; ond of the oil suction pipe and the has completed this stroke and has engine power, is

tight pump is not supplied. On the other travelled upward on the next, or less evil than too adjustment-the lack of some free hand, oil may enter the pump suc- compression stroke, about one-sixth space or clearance between valve-tion at first, but after a time ice of the upward travel of the crank stems, and push-rods, during the crystals may be drawn in and clog pin, when it is closed. porlod in which the valves should the pipe. We don't know exactly

The reason for having this valve bo fully closed. Valve parts always what happens, but advise you to try open so long is due to the great tend to wear to a loose adjustment, to adopt a more nearly coldproof speed of the engine. Many engines never to an overtight one, but when oil and frequently to draw off, make about 1,200 revolutions in a éver valves have been ground and through the drain plug, any water minute when the car le travelling even sometimes when the cylinder- which may have collected in the oil-thirty-five miles an hour. From this you will see that the piston head has been removed and replaced reservoir. merely, there is likelihood that valve)

Question.I think there is a pla.makes cach stroke in about one- adjustment may become too tight, ton stap in one cylinder of my 1926 fourth of a second.

This is a very short space of through the incidental taking up of

This may prevent engine, is there any way of tell- oll clearance. the complete scating of some of the ing which cylinder it is in, without time, and you can readily under- stand that, as the incoming gases taking off the head?

must pass through pipes and a valvos and cause them to leak gas sufficiently to spoil the performance Answer--The cylinder can prob- valve, which tend to throttle or of the engine or even to prevent its ably be identified by tho ues of one check their passage, they must have being started,

Grinding 'n valve of the pump type of engine testers, time enough to get into the cylin deeper into its sent, brings the bot-The suspected piston is set at about der. It is to give the gases time tom of its stem nearer the top of half stroke and the hand of the enough to enter the cylinder that its pushrod and, unless this change tester operated to give alternate the inlet valve is held open for the is counteracted by adjusting the top pressure and vacuum, causing the extra one-sixth of the crank pin of the pushrod alightly lower there loose piston to tilt and produce a travel as mentioned above. may be no clearance left at all and characteristic knock. It can prob Because of the great engine the valve will hold open and leak. ably be located also, by shortcircuit-speed, the exhaust is also opened for An engine with valves that thus ing spark-plugs, with the engine a comparatively long time, it never completely close, is often very running, preferably before it is being opened when the crank pin hard or impossible to start, for an warmed up. Correctness of the has still to travel one-sixth of the unseated inlet-valve will allow results obtained by the above way down on the stroke before the the charge to escape on the methods can be further checked by exhaust, or on the power stroke. THE DRAGON MOTOR CAR CO. LTD. (compression stroke and a leaky ex-injecting a liberal quantity of very it is held open for the full upward haust valve will permit an air leak heavy oil into the auspected cylinder exhaust stroke and slightly after that renders the mixture too lean through its spark-plug hole and im- completing this stroke. to ignite. Even if an engine with mediately running the engine. If The reason is this. The gases, imperfectly sented valves is started, the slapping ceases, due to the after explosion, are under a very n cylinder the exhaust valve of cushioning effect of the heavy oil, high pressure, and wille they lose which is holding open, will fire only it may be inferred that the piston most of this pressure in pushing at times and when it does fire, its in the cylinder under treatment is exhaust valve will be sealed and the loose one. warped by the flaming gas, prema- turely escaping past it.

All prices subject to change without notice.

Keen appreciation has grected Oldsmobile's smart new beauty. Naturally such modish lines and striking colours would win the lion's share of admiration from those who know it only by sight. But every day Oldsmobile perform- ance seizes the attention of those who never knew it before- because you can't know it till you drive the car. This thrilling, smoother performance is the crowning feature of Oldsmobile the overflowing measure of value now youra at prices lower than ever before.

Telephone Central 1246 or 1247.

88 WONG NEI CHUNG ROAD, - - - HAPPY VALLEY.

1928

Triumph Cycles and Side Cars:

HAVE ARRIVED.

NEW COLOUR

NEW DESIGN

and wonderful to look at.

Alex. Ross & Co. (China) Ltd.

Prince's Building and No. 1, Chater Road.

A single

inlet valve holding open will entire- normal carburetion and

GENERAL MOTORS (G. M. C.) TRUCKS

Type T-20 Trucks are powered with the famous Buick Standard Six valve-in-head Motor-six 36" by 415”. Cylinders-207 "cubic inches piston displacement R.A.C. Rating 23.44 II.P.-develops 50 H.P. at 2,000 R.P.M.-63 H.P. at 2,500 R.P.M.-20" wheels-30 x 5 xima-80 x 5 Pneumatic Cord Tyres, front and, rear-16" brake drums-454 square. inches braking area. These General Motors Model T-20 trucks have a maximum. payload capacity of 3,000 pounds and are available in 'the following chassis types:

T-20-A chassis 132" wheelbase

T-20-C chassis 150′′ wheelbase

G$1,345. G$1,465.

The above prices are for delivery in Hongkong or Kow- loon. All prices and specifications subject to change without notice. General Motors, Trucks are supreme in flexibility and in endurance. Equally remarkable are the low prices which are only possible because of the tremendous volume of General Motors Production. General Motora (G.M.C.) chassis are available in payload capacities ranging from 1,000 to 20,000 pounds "A Truck for Every Purse and Purpose."

The Dragon Motor Car Co., Ltd.

!

Telephone Central 1246 or 1247.

33, WONG NEI CHUNG ROAD.

ly defeat Burbulion, may cause 90-MILE MOTORWAY. there would be no suction due to past top centre on the suction

HAPPY VALLEY.

#

pletion of this stroke.

To set the valve timing gears after they have been removed, pro«, ceed as follows:

Remove the genr

(or chain, if chain drive) and then bring the piston to top dead centre and a very slight amount beyond, and re- place the gear.

the piston down, whon the power is opened about one-sixth of the stroke is completed they will still way before the beginning of the ex- be under considerable pressure.haust stroke. Now, if there were still to be pres- From the above we see that the sure in the cylinder when the pia-inlet valve opens when the crank ton starts on its suction stroke, pin has travelled about ten degrees the downward travel of the piston, stroke and closes about thirty de- backfiring into the intake and is likely to cause the engine to stall

as the old gasses would aimply ex-grees after the crank pin has com-

Generally the gears are marked. incessantly. Even though a perfect grinding job has been done on ex- Birmingham to Liver-pand until their pressure was gone. pleted the suction stroke and is on

So you see that there must also tho, compression stroke. The ex- There will be a mark on the tooth- be considerable time allowed to let haust valve opens about thirty-five of one gear and a mark at the root the exhausted gas lose its pressure, degrees before the boginning of or hollow of the other. The mark- or, in other words, come to atmos-the exhaust stroke and closes ed tooth should mesh into the mark- pheric pressure. Thus, the valve about five degrees after the com-ed hollow.

pool Scheme.

Traders of the Midlands

are

hnust-valves, if any of them are kept from Beating fully, through faulty adjustment, the effect of the grinding will soon be lost, as their much interested in a proposal to faces and sents will become burned, lay down a big motor-way from almost at once. Every time valves Birmingham to Liverpool in order are ground and even every time the

cylinder-bend in disturbed, as soon to link up the industrial areas of as the head stud-bolts have been the West Midlands with the sea. fully tightened, each valve should The road will, be 30 miles long, be inspected with the crankshaft will cost £6,000,000, and will, in in the position in which it should be the course of its construction, find closed to see that there is a great employment for 10,000 men. clearance between its stem and its It has long been the dream of pushrod as the manufacturer re Midland industrialists to obvinte cummends, usually from 0.001 to

0.010 inch, incasured with the en- the delays and hindrances experi gine hot, by means of a thin strip enced in existing transit by estab- of metal or feeler of the required (lishing a means whereby their thickness. A valve-grinding opera- merchandise could be taken direct Lion, unless it is followed up by a from their factories to the port. careful adjustment of valve clear-Hitherto the only, scheme that ances, is likely to do more harm has appeared to be at all practic- than good.

able has been the development of the existing canals, and for some- Interrupted Oil Circulation.

thing like twenty years various Question-During the recent ex-proposals for connecting Birming- tremely cold weather, after start-ham with the sea, either by way ing the engine of my car, the oil- of the Morsey or the Severn, have gage would show pressure for afbeen the subject of exhaustive in- minute or so, and then would stop quiry. Nothing definite, however, registering. Can you explain this? has resulted, and just as the whole The lubricating system works fine matter had come to be regarded in warm or medium cold weather. as hopeless, and business men Answer. This trouble is prob- were predicting the migration of ably due to the use of oil that stif- big industrial concerns from inland

Studebaker

HONGKONG HOTEL GARAGE

(THE HONG KONG SHANGHAI HÓTELS, LTD.)

4

CAR BALES

ACCESSORIES

Phone 0.4755

SERVICE

PARTS

Phone 0. 4602

Studebaner

areas to moro convenient sitea nearer the coast, there le evolved. a scheme which is infinitely more acceptablo than the development of the, waterways, and which is being heralded by traders and local authorities in the Midlands with equal enthusiasm.

The idea is to start the road as near the mouth of the Mersey as possible" on the Birkenhead side, and continue it by way of Chester, Crewe, Newcastle-under-Lyne, Stafford, Penkridge, Wolverhamp ton, and Stourbridge, to Birming ham. The road will be construct- ed. specially to meet the needs of heavy transport, und will contain neither serious curves nor serious gradients. The road will to all Intents and purposes be 'exclusive- ly a traders' route. It la proposed to make a levy "of one farthing per ton, over all, on all vehicles using the motorway, a charge which, it is claimed, will represent | an appreciable saving on the pre- sent transport costs. Moreover, there will be a considerabic saving |of time, as it will be posible for the return journey to be under- taken in at least half the time of the single journey under present urrangements,

The scheme has already been [discussed at a preliminary meeting fof representatives of leading busi- ness concerns and local authori- ties in the Midlands, under the chairmanship of Sir Francis Joseph, and a further meeting is ŝto be held shortly in Birmingham,

at which all the local authorities: and all the industrial and finan- cial interests in the Midlands will be represented.

Scoring Greatest Success in All Chrysler History

THE ILLUSTRIOUS NEW

CHRYSLER

72

MOST

unusual, even for Chrysler, has been the reception given to the Illustrious New 7.

But no other result could have been possible, because no other car combines such tare quality and value,

Before the "72,” no [car in its class or even in the more expensive group pro-

Counterweighted 7.

Bearing Crankshaft and Rubber Spring Mount- ings Made Possible for the First Time at Such Prices

vided counterweighted 7-bearing crankshaft in a 75 horse-power engine; spring ends anchored in blocks of live rubber; and long, roomy, handsome bodies in such correct taste.

Every Chrysler dealer is eager to show you the Illustrious New "72"; to put it through its paces. Only by riding in it and driving can you fa- millarise yourself with this new per- formance, this new smartness that has been responsible for the greatest success in all Chrysler history.

A. LUNG 8 CO.

Sole Agents

19, Queen's Road, C.

Phone C 1219.