CYLINDERS AND PISTONS.

Press, Volume LXIII, Issue 19161, 18 November 1927, Page 4

CYLINDERS AND PISTONS.

"Roadster" invites articles and paragraphs of intereet to motorists for this page. NOTES. Ihe moiormg industry is> generaaly accepted to be somewhere in the region of 3o years old, but over 50 years ago a home-made steam car was to be seen on tb© Great North road, in England. This was made by two apprentices to an engineering works, Bradley and Wansbrough by name, and it wai bniit in a disused workshop which they rented lor the princely sum of Is per week, the machine 'was a tricycle weighing i'b cwt. Tlie sheet metal body consisted largely of a 10-gallon water tank, a bunker to hoid Hi cwt of coal, and a tool locker. At the front, just behind the steering wheel, was ati enormous vertical Ixnler complete with funnel. Solid tyres on oust iron wheels were hardly "calculated to minister to comfort, but. the car did 0 m.p.h. until it broke down, and the Grantham poh'je summoned the youthful inventors for obstructing the highway. A ''Motor Hotel" of the sky-scraper variety, -9 storeys high, and affording accommodation for 1050 cars, is to bw erected in New York by the Kent Automatic Parking Garage, Inc. The plans include a modern automobile "laundry," space where owners or chauffeurs can make their own minor repairs, a large chauffeurs' room and waiting rooms. No cars will be stored on the ground floor, that being devoted solely to their reception and departure. The customer will merely drive in, phut off his engine, receive his check and leave. Then, until he himself restarts his engine to drive away, the car is nayer moved by its own power, all handling and parking being done by electricity.

Before creating ,1 by-law to regulate car-parking in Broadway, the Newmarket Borough Council will put two suggestions to the. test (states the "New Zealand Herald"). After conferring with the Aucklihid Automobile Association the Council has decided to enforce parking, at an angle of about 50 degrees to the kerb. There has, however, been a division of opinion regarding the best method of approach to the standing position. Lines are being drawn at an angle of 52i degrees to the kerb and a traffic inspector will be on duty in the street on Saturday to direct all motorists tc» park witli the front of the car to the footpath. On the following Saturday drivers will be required to back into the kerb. Af lev observing the manner in which cars :ue controlled the Borough Council will incorporate the approved method in a bylaw.

Dublin is fortunate in being able to use for the purpose of motor-cycle racing the Phoenix Park, a venue which Major Segrave has described as the finest speedway in the world.

In rain and a half gale the British motoring Grand Prix was decided at Brooklands recently. The race was 125 laps, equal to 327 miles. Eleven started—nine Frenchmen and two Englishmen. The event was won by Benoist, a Frenchman, driving a Delage. His average speed was 85.59 miles an hour. The two Englishmen, driving Thomas Specials, retired before half-way.

Adams, Ltd., have received the following cable from the Studebaker Corporation, Sydney:—"Two Studebaker Commander roadsters and one Commander sedan established new official stock model world records for speed and endurance between October 18th and November 4tb at Atlantic City speedway. The roadsters completed 25,000 miles in less than 23,000 minutes, establishing an average of 65.35 miles per hour. The sedan completed 25,000 miles in less than 25,000 minutes, establishing an average of 61.98 miles per hour, all stops included. The records were supervised and checked hv the Contest Board of the American Automobile Association."

PETROL TAX.

COMMERCIAL VEHICLES. ALLEGED INJUSTICES. The proposed petrol tax and the burden it -would impose upon owners of commercial vehicles and lorries were discussed at the last meeting of the Council of the Wellington Chamber of Commerce. Owners, it was said, were perturbed by the tax, which would be in addition to, and not in substitution of, present license and other fees. A heavy lorry was estimated to have a life of only five years, and in that time an amount equivalent to half its original cost would be paid away in taxes and fees, apart from power and running costs. As regards wear and tear of the roads, the taxes would place an especially heavy burden upon the heavier commercial vehicles, totally out of proportion to any damage caused when compared with motor-cars which travel at a higher average speed and pay taxes and fees which are trifling when compared with the utility vehicle. If motor taxation is to be based upon the use of the roads, it appeared soma concession should be given to vehicles- uow paying the heavy traffic fees. It must not be overlooked that these vehicles are very heavy consumers of petrol, with a low mileage per gallon. In "Wellington these vehicles also have to pay the Hutt road tax, a tax which is not borne by motor-lorries from outside districts that come into the city and carry goods away in competition with the railways. The local lorries on the contrary act as feeders to the railways. It was suggested that under the proposed petrol tax the cities would pay out of proportion to the amount which would be spent within their areas, and those districts which had already rated themselves to provide goods roads were unlikely to derive much benefit from the increased taxation unless some of the proceeds of the tax were applied to meeting sinking funds and interest charges on the loans already raised for the specific purpose of constructing modern thoroughfares. The matter will be discussed more fully at a meeting to be called for the purpose.

There's always a snag in every good thing. The better your brakes, the greater the danger to your rear bumpers.

i UNIVERSAL TROUBLES. WHERE CARE IS REPAID. 1 (cpsciALX.7 iniiitn m niu.) I (By Major F. A. C. Forbes-Leith, ' F.K.G.S.. Author of "By .Car to India.'-') In the course of their motoring careers a good many drivers are bound to run up against the trouble of worn cylinder walls. This condition may be brought about as a result of long usage. On the other hand, if a car is run for a few miles without sufficient lubricating oil, it will sustain more damage in that short' distance than it would get in the course of ordinary wear and tear for 25,000 miles. Many motorists are inclined to be misled as to the proper method of correcting this damage. They are often badly advised, and the result in that entirely inadequate repairs are mad«, to the detriment of the car and the discomfort of the owner. Common Errors. As it is an inconvenience to a good many owners to liave the car out of commission, they allow themselves to be prejudiced, and the first thing they think of, as a rule, is a new set of piston rings, forgetting that no matter how well a ring fits, it is impossible to have perfect compression with a • badly fitting piston. Another panacea, which a good many are apt to fly to for this trouble, is the oversized piston, and this is certainly a step in the right direction. It must be remembered, however, that the action of pistons in the cylinders are lateral in relation to the cylinders, with the result that the cylinders do not get evenly worfi around their whole circumference; and if measured, it will be found that they have usually worn oval to a slight degree. The futility of putting an over-sized round piston into an oval cylinder can easily be seen, and the natural result will be tremendous loss of compression. Another most unpleasant symptom of this state is the knock caused by the piston slapping from side to side in the cylinder. Misleading Symptoms. This knock is apt to be mistaken very often for bearing trouble, and I have come across many instances where motorists have spent quite a deal of time ' and money in having their bearings refitted in order to eradicate this noise, only to find it still there when the engine is again assembled and started i off. As a matter of fact, perfectly fit- j ting bearings will accentuate a piston slap. • . Although it will cost more money, there is only one method of caring this trouble whjch is in any way satisfactory; that is, to have your cylinders rebored or else trued-up with a honing machine. Many automobile engineers still resort to the old method of dollying out the cylinders with a semi-circu-lar piece of wood and emery cloth. But j I consider that no matter how skilful! a mechanic can be at this process, he cannot come to within a degree of the correctness that can be obtained from a machine. If this process is a little expensive, new pistons are cheap, and if the job is done thoroughly, there is no reason why the balance of the engine should be disturbed in any way. Fitting Piston Kings. I am all in favour of fitting piston rings to the cylinder walls in the same way that a bearing would be fitted to a crank shaft pin. Many engineers do not trouble with this process, and leave the piston rings to fit themselves to the walls of the cylinders by the friction which comes about when the engine is running. If the rings happen to be made of harder metal than the cylinders, the latter are bound to get scored by this process, although it may be to such a fine degre as to be hardly perceptible. It must be remombered, however, that the perfect explosion can only be brought about by the ignition of a well compressed charge of gas, and if your cylinder* are scored in any way, a certain amount of that charge will leak down the walls and help to dilute your crank-case oil with petrol. This process of fitting the piston rings is quite: simple. They should be fitted to the piston and smeared with a colouring pigment, and worked up and down in one direction. Where they do not make a perfect contact with the cylinder wall, they should be treated with a very fine file and emery cloth until a perfect contact is made. Let me advise motorists to pay particular attention to their cylinders, and •to remember {hat a few pounds spent in correcting this serious fault may add months, or even years, to the life of their cars.

THE CLUTCH.

CAUSES OF TROUBLE. It occasionally happens that a clutch becomes very fierce, and in consequence very unpleasant to use. This may be due to the clutch mechanism becoming stiff and working in jerks, or it may be owing -to the friction surfaces getting out of order. In the former case the remedy is obvious; the clutch-releas-ing mechanism must be carefully cleaned and oiled. If, however, the parts are kept well oiled or greased from the beginning, this trouble is not likely to occur. Friction surface trouble is more likely to occur with leather-lined cone clntches than with plate clutches lined with Ferodo or .some other bonded asbestos fabric. It is a good thing to wash the clutch out with petrol rather than paraffin and to use a very thin oil (3 in 1 is excellent for that and many other purposes). Further if an owner finds that his clutch tends to become fierce he should make a point of keeping the clutch pedal down whenever the car is left standing for more than a l'ttle while. This has the effect, by relieving the pressure on tha lining, of allowing it to swell and become softer, and in consequence much sweeter in use. Thin oil should be used about twice a week.

If a car is fitted with a dry clutch it should not be necessary to apply either petrol or oil to it to make it sweet; but if it should have been unintentionally oiled, washing it out with petrol will cure the slipping that is likely to result. When a clutch slips on a journey it is generally possible to proceed by using one of the lower gears, because that eases the strain on the clutch by substituting a faster movement while the torque on the rear axle remains unchanged. But it must not be forgotten that a slipping clutch, if it is left alone, is likely to become worse, and that quite soon; therefore it should have attention as soon as possftljh