bluuebunny/crossref_metadata_2025 huggingface dataset:
Notes on Test Methods and Some Instruments
Authors: Stead E. B.
Published: June 2010

To obtain true factual results from tests carried out on the test bed and on the road, instruments are necessary. The author describes his own experiences with various instruments and test methods, for example, the use of thermocouple sparking plugs for carrying out distribution tests, and the advantages of and characteristic results obtained from a smoke meter on a compression-ignition engine. After a brief comment on electronic instruments in general, he describes the balanced-pressure method of obtaining indicator diagrams at high speed, using a cathode-ray apparatus. Some typical results are given, and the methods by which the apparatus with a few additions can be used to measure torsional-vibration amplitudes of crankshafts (with practical examples), and by which a friction damper is adjusted to the correct condition, are shown.

The final section deals with road testing; in this the author advocates the use of a recording accelerometer for obtaining greater accuracy in brake and acceleration tests, and shows how such an instrument can also be used for measuring cornering forces, assessing the riding qualities, or recording gradients. Some results are given, and the design of such an instrument is dealt with.
Recent Developments in Automobile Transmissions
Authors: M'Ewen Ewen
Published: June 2010

The paper is limited to the gearbox and to devices replacing the gearbox. The varied requirements of the transmission for different types of service and how far automatic gearchanging is desirable are discussed, and the author investigates the gain to be expected from infinitely variable transmissions. The increased popularity of synchromesh and the description of, and the present trend in current types of layshaft gearboxes, and current types of epicyclic gearboxes with the development of cone clutches instead of band brakes for epicyclic unit control are next dealt with. Under the heading of unorthodox gearboxes the German Z.F. layshaft box with electromagnetically operated clutches for synchronizing and engaging is discussed, as is also the synchro-self-shifting (S.S.S.) gearbox with traction clutch maintaining tractive effort during a change. Hydraulic transmission (including recent developments in fluid couplings), the present position of torque converters in road vehicle practice, and the possibilities of the combination torque converter and fluid coupling follow; finally, an attempt is made to forecast the future trend.
Basic Problems in the Engineering of a Modern All-Metal Motor Body
Authors: White E. S.
Published: June 2010

Modern trends in car fashions are aggravating the problems of the body engineer and British designers are further hampered by the degree of economy which they must needs exercise in the use of expensive tools. The aim of this paper is to make such problems more widely known among those connected with other aspects of car design and production. Designing for reduced weight, air resistance, and easier cleaning is advocated and a warning is given against production complications and increased costs arising from changes made for reasons of fashion.

The range of materials from which a body may be made is described in some detail and it becomes obvious that steel still shows considerable advantages over all others. The relative merits of different forms of construction are examined in the light of quantity production. The method of assembly of a body has now to be studied in relation to the present practice of exporting vehicles in a partly-dismantled condition and it is pointed out how components may be made self-locating in order to render the use of jigs unnecessary in overseas assembly centres. An example is given of the way in which multiple pressing operations can be facilitated by careful sequence planning. The inclusion of a section on corrosion prevention is of particular value in view of the increased period of life expected from cars at the present time.
Lubrication of Engines in Public Service Vehicles
Authors: Wilford A. T.
Published: June 2010

In the course of use an engine lubricating oil becomes contaminated with the products of its own breakdown, and with others derived from incomplete combustion of the fuel, leading to objectionable deposits influenced not only by the characteristics of the lubricant but also by other factors such as engine design, operating conditions, and maintenance. Fuel characteristics—such as volatility, ignition quality, and sulphur content—affect lubricating oil behaviour. The effect of viscosity on fuel consumption is explained. Increase in engine output for a given weight and size, together with operation at high temperature and load, have an adverse effect. Results obtained from service tests with an oxidation-inhibited oil and with a fully-detergent (“heavy duty”) oil are described, and examples are given of the use of data obtained by examination of used oils, considered in conjunction with statistics derived from a study of the condition of the engines.

Physical specifications for non-additive type lubricants can be compiled to define oils which have proved satisfactory. The present position in Great Britain regarding specifications for detergent (H.D.) oils is reviewed; conventional specifications are inadequate to describe this type of lubricant, the behaviour of which can be determined only by engine tests.
The Propeller Shaft or Hooke's Coupling and the Cardan Joint
Authors: Evernden H. I. F.
Published: June 2010

The purpose of this paper is to review the problem of designing a satisfactory open shaft-coupling between the power unit and the rear axle of a motor car.

The vogue for a low car and a low, flat floor coupled with the need for adequate ground clearance under the power unit demanded by export conditions, creates the need for a divided “propeller” shaft.

The cyclic forces on the centre bearing of such a divided propeller shaft are determined mathematically, and the story is told of the development of a design of centre bearing intended to prevent these cyclic forces being felt by the occupants of the vehicle.

The cyclic bending which is induced in the propeller shaft is shown to reduce its whirling speed below that of a freely revolving shaft.
Fuel Anti-knock Requirements of Automobile Engines
Authors: Williams C. G.
Published: June 2010

While there are other approaches to the problem of improving overall efficiency, the paper discusses mainly the limits imposed by fuel anti-knock requirements on thermodynamic efficiency. After reviewing the basic concepts of knock and octane number, knowledge acquired during the 1939–45 war on aviation engines is summarized. The large production of aviation gasoline during the war gave rise to false hopes of a super-fuel for motor vehicles. Post-war fuel production difficulties due to shortage are mentioned, leading to the decision to construct refinery equipment in the United Kingdom. A brief description of this follows, and of the essential performance characteristics of the fuel. This leads to a discussion of octane requirements of automobiles, of temperature sensitivity of fuels, and of engine severity. Reference is made to the influence of the following engine design and operational factors on octane requirements: compression ratio, overhead versus side valve, mixture temperature, mixture strength and distribution, valve overlap, ignition advance, engine speed, coolant temperature, and combustion chamber deposits. It is concluded that, by increased cooperation in the United Kingdom between fuel suppliers and engine designers, much can be done to make better use of the fuels available now and in the coming years.
Sulphur in Diesel Fuels
Authors: Broeze J. J. , Wilson A.
Published: June 2010

Sound reasons exist for the current interest in the sulphur content of Diesel fuels and the authors give a brief historical account of the recognition of its undesirable effects. Notwithstanding that it is, technically, quite feasible to desulphurize the fuels, other considerations compel the acceptance of a significant sulphur content for some time to come, and it may be expected that, as a result, engine wear and fouling will be accentuated unless appropriate precautions are taken. Engines of different types and design will be differently affected. An account of relevant physico-chemical reactions of sulphur in the engine focuses attention on the trioxide produced during combustion as the principal cause of ill effects. Amongst precautionary measures, certain beneficial rules of engine operation (particularly as regards coolant temperature) and design are proposed. Importance is attached also to metallurgical expedients such as chromium plating, and to the use of special additive-type lubricants. It is thus made evident that by suitable design, operation, and lubrication of the Diesel engine, it can be made to consume fuels of a higher sulphur content than has hitherto been usual, without adverse results. Instances of the satisfactory use of an actual crude oil containing 3 per cent sulphur and an under-boiler fuel oil of 2–5 per cent sulphur content are given.
Electrical Equipment for Passenger Cars
Authors: Kendall M. W.
Published: June 2010

The paper sets out to consider the present-day practice in British automotive electrical equipment, comparing this frequently with British practice prior to 1939 or current American practice wherever appropriate.

It commences by considering the generating and energy-storage part of the system, dealing briefly with the provision of A.C. or D.C. equipment and the relative merits of 12-volt and 6-volt equipment.

It then goes on to consider the operating and power-consuming parts of the system in fairly considerable detail, making particular note of the reduction in size and weight of generators which has been made possible in recent years by the use of new insulating enamels and of light alloys where practicable. The use of higher speeds is generally possible only where maximum car speeds are not very high, due to limitations imposed by centrifugal forces on armatures and the need to provide the rated output at a fairly constant road speed.

Voltage regulators are dealt with in some detail with a general description of the British compensated voltage-control system and the transatlantic current-voltage type using two separate regulating circuits in series.

With regard to batteries, the main development has been an improved paste which was developed during the 1939–45 war for dealing with low temperatures and which is now in general production.

The problems of noise, power, and premature pinion ejection concerning starter-motors are discussed, with a comparison of the performance of 6- and 12-volt machines and of the various types of pinion-engaging mechanisms of the positive-mesh and inertia-meshing types, together with a reference to the comparatively large amount of power required to start a small engine.

Developments in ignition equipment have not been great in recent years, but the point is made that an improved system will need to be developed for the higher compression ratios which are impending.

The paper deals briefly with windscreen wipers, heaters, demisters, horns, direction indicators of the semaphore and flashing signal type, instruments, actuating motors, relays and protective devices, and also touches briefly on the subject of radio suppression for car radio and television.

The paper concludes with a discussion on head lighting and dazzle.
Piston Assemblies for Road Transport Oil Engines
Authors: Hepworth J. L.
Published: June 2010

After reviewing the more usual types of piston failures such as breakage, seizure, ring sticking, land breakage, land scuffing, and groove destruction, means are suggested for their avoidance. There follows a consideration of the limiting factors of piston life, as indicated by the oil consumption of the engine. Dangers of overscraping new engines are emphasized and a method of retaining a minimum consumption over a long life is suggested. Examination of the rates of wear of the various components of the piston assembly leads to the conclusion that the top compression ring is the weakest point. Service test results with different piston ring materials are given and improved materials are suggested. Chromium-plated piston rings give the best results and are recommended for use as the upper compression ring. Finally, suggestions are given for designing the successful oil engine piston with a strong recommendation for the use of 12 per cent silicon alloy material and an adequate path for heat flow from the piston crown to the ring zone. Gudgeon-pin design is an important feature and design formulae are given. In summarizing, a model piston ring layout is given in detail.
Some Factors Governing the Performance of Crankcase Lubricating Oils
Authors: Towle A.
Published: June 2010

The paper deals in turn with the basic requirements of a crankcase oil; chemical and physical tests on new and used oils; viscosity, S.A.E. numbers, and viscosity index; common problems arising in lubrication; ring sticking; engine wear; oil consumption; bearing failures; engine deposits; the grouping of oils; the influence of Diesel fuel and gasolene on engine deposits and wear; engine laboratory tests; the rating of oil performance on an engine test; and finally, the correlation between field and laboratory tests.

It attempts to show that unsatisfactory engine life is not necessarily connected with the quality of the lubricating oil, and that many of the faults often attributed to the lubricant are, in fact, controlled by incorrect engine design, excessive operating conditions, or poor maintenance. Better results can usually be obtained by the use of additive treated oils.

Reference is made to the Supplement 1 series of oils which effectively deal with high-sulphur Diesel fuels, and examples are given of bench and field tests carried out on straight and treated oils.
An Application of Petrol Injection to Automobile Engines
Authors: Barrington R. , Downing E. W.
Published: June 2010

The paper recounts the results obtained in a series of experiments carried out with the object of examining the claims made for improved results, both in fuel consumption and maximum power, which could be obtained by substituting a petrol injection system for a carburettor.

The experiments, carried out on four-cylinder engines of approximately 1·5 litres capacity, led to the development of a satisfactory system capable of giving equal fuel distribution to all cylinders with a tolerance of ±2 per cent at all loads. They showed that, for engines of this order of size, manifold injection was superior to direct injection and established that petrol injection will not give any better combustion efficiency than carburation. Hence any saving in fuel consumption obtained can only be due to better fuel distribution between cylinders, better matching of fuel/air ratio to a desired value, or increase in compression ratio made possible by the elimination of the hot spot. Under certain conditions the resultant saving in fuel at part load on bench tests could amount to some 10–15 per cent.

Maximum power can be increased by some 15–20 per cent by elimination of the choke, and still more if the compression ratio is increased slightly to take advantage of the reduced temperature of the incoming charge. Road tests in general confirmed the results of bench tests, but brought out the effect of many other factors which affect fuel economy. In order to properly evaluate these a number of experiments were carried out which are of interest and value as affecting the problem of fuel economy in general.

Starting at low temperatures requires very considerable over-fuelling with a petrol injection system, just as in the case of a carburettor, but such a system may be made to give better control during the process of warming up. In the authors' view an engine fitted with petrol injection is pleasanter to drive as a result of its inherently better idling, more uniform and smoother torque and increased power at full throttle. The results obtained, however, while attractive, do not bear out some of the more exaggerated claims sometimes made by advocates of petrol injection systems. No attempt is made to urge the introduction of petrol injection and it is left to the industry to decide whether, in view of the results obtained, it is felt that a petrol injection system with its concomitant increase in first cost is worth adoption.
Metal Transfer from Piston Rings to Cylinders during “Run-in”
Authors: Strang C. D. , Burwell J. T.
Published: June 2010

Piston rings with radio-active wearing-surfaces were used to study the micro-welding between rings and cylinder wall during “run-in” in a small, water-cooled, internal combustion engine. The results indicated that micro-welding and the accompanying transfer of metal were present under the mildest conditions of engine operation, including motoring with the engine cylinder-head removed.

The distribution of micro-welding along the ring-travel was found to correspond to the wear profile observed in engine cylinders by other workers. Such transferred material may play a part in the formation of the “glazed” layer which is said to be present on “run-in” cylinder walls and rings. The presence of transferred metal at all points along the ring-travel indicates that the piston ring was not fully supported by a hydrodynamic oil film of sufficient thickness to separate completely the surfaces of the ring and the cylinder wall.
Significant Contributions of the Diesel Research Laboratory
Authors: Rosen C. G. A.
Published: June 2010

This review of Diesel engine development is based on the work carried out at the Diesel Research Laboratory of Caterpillar Tractor Co. under the sponsorship of the author as Director of Research.

For many years intensive effort has been made to understand the combustion process in this type of engine by a better knowledge of the fundamentals of ignition and the mechanism of the combustion process, and this study has been developed in the laboratory on a competitive basis. Originally six combustion systems were put to trial and a modified precombustion-chamber engine won the palm of victory on the basis of its ability to maintain uniformity over extended periods of operation.

Briefly, the character of the comparative combustion studies followed two general classifications: (1) visual combustion studies; (2) study of combustion-chamber deposits.

In order to make extended studies of the combustion phenomena by visual means, a quartz window was designed to achieve maximum cleanliness without the distraction of soot condensation on the cold windows.

The author describes the precombustion-chamber process, and deals with the composition of combustion gases, flame duration, temperature distribution, the mechanism of ignition, and combustion-chamber deposits. He also discusses the development of fuel-injection equipment, pretiming, precalibrating, and the evolution of the fuel pump; he describes the characteristics of several types of check valve and fuel valve, and the fuel-pump control of engine torque characteristics. Spray characteristics and the flow through the fuel-valve orifice are also examined. Comments are made upon materials for cylinder liners and piston rings, and the effect of fuel inclusions on cylinder wear; lubrication is also considered.

It is believed that excellent performance has been achieved in the precombustion-chamber engine with a minimum of complication in the fuel-injection equipment, and that the development of this principle of combustion has not yet reached its limit of progress.
An Experimental Investigation into Pre-ignition in the Spark-ignition Engine
Authors: Downs D. , Pignéguy J. H.
Published: June 2010

Pre-ignition and auto-ignition are uncontrolled ignition of combustible mixture in an engine by a hot surface. Pre-ignition is distinct from “knock” or “detonation” which is caused by the rapid combustion of the last part of the mixture following the initiation of flame by a spark. More work has been carried out on knock than pre-ignition because knock sets the primary limit to the possible power-output and fuel economy of an engine. Owing to increases in engine power in recent years, however, interest in pre-ignition has been revived, and this paper describes an investigation which was primarily directed to finding the pre-ignition ratings of various fuels.

Two methods of obtaining pre-ignition ratings have been developed; with one a 500 c.c. single-cylinder water-cooled unit is used, having an electrically heated hot-spot to induce pre-ignition, and with the other a single-cylinder air-cooled aircraft engine with an air-cooled pre-igniter is used. A rating scale has been constructed in which iso-octane has been given the value of 100, and cumene zero. A large number of pure fuels from the paraffin, naphthene, aromatic, and alcohol groups have been rated for pre-ignition tendency using these methods. In addition, typical commercial motor-fuels, motor-racing fuels, and water-alcohol injection fluids have been tested. The relationship between pre-ignition tendency and the temperature of the hot-spot with normal running and with pre-ignition conditions has been established.

The effects of engine variables, for example, mixture strength, speed, ignition advance, and air and cylinder temperatures, on pre-ignition, have been studied, in addition to the effects of important fuel additives such as tetraethyl lead and the aromatic amines. The additive tests include substances, such as formaldehyde and nitrogen peroxide, which are of interest from the chemical aspect and, based on the results, some information on the fundamental chemical processes involved in hot-spot ignition has been obtained.
An Analytical Approach to Automobile. Valve Gear Design
Authors: Bishop J. L. H.
Published: June 2010

In the automotive field during the last decade, owing primarily to increases in maximum engine speed and the almost universal use of overhead valve gear, increasing attention has been focused upon improper valve functioning which causes noisy operation, excessive valve spring surge, valve seat pounding, and exhaust valve burning.

With the conventional design of cams no allowance is made for the flexibility of the push rod and rocker, consequently in general the accelerations imparted to the valve are much greater than is necessary at high speeds when inertia effects build up.

A general mathematical analysis of the conventional three-arc cam is presented, introducing the terms “eccentricity” and “instantaneous radius”, and this is followed by a similar analysis of the new cam profile using the same terms, together with the method of correcting the cam profile for highspeed operation. It is also shown how the new general equations can be used to deduce a variable eccentricity ramp, the purpose of which is to take up clearance at variable velocity.

The effects of the new cam profile on horse-power and thermal efficiency are shown; the effect of the acceleration characteristic on valve spring design also is illustrated, and a comparison shows the reduction in spring weight made possible by the elimination of valve spring surge.
Shock Absorbers
Authors: Kinchin J. W. , Stock C. R.
Published: June 2010

The progress made in suspension during recent years, especially with regard to forms of relatively frictionless springing, makes the shock absorber, now generally known as the suspension damper, an essential part of the suspension system.

The simple friction type of damper has been displaced from universal popularity by some form of hydraulic control, and it is to the hydraulic damper that the paper is devoted. The three main types of hydraulic damper mentioned are the vane type, the lever-operated piston type, and the direct-acting telescopic type.

Design requirements for recuperating, transfer, and pressure valves are stated, and types of seals, and sealing problems, are given. Reference is made to the desirable characteristics of damper fluids, together with a summary of tests on various fluids.

The causes of noise—the most common being knock, swish, and squeak—are investigated, and remedies for their elimination are discussed. Various tests on dampers are described, and work diagrams, from which it is possible to analyse the various common faults, are given. Ride determination is mentioned and a damper calibration chart illustrated.

A review of the use of dampers for auxiliary purposes is made, and the type of damping that is required is considered.
Factors Affecting the Utilization of Anti-knock Quality in Automobile Engines
Authors: Davis J. D.
Published: June 2010

In this paper the author has compiled an interim report based on a close study of the anti-knock requirements and fuel utilization of a number of modern automobile engines.

It is found that the maximum octane requirements of most of the engines tested are related to then-indicated mean effective pressures. Considerable differences, however, exist in the performance of the engines when run on a fuel of the same quality in each case.

A comparison is made between several engines operated on gasolenes of United Kingdom “Pool” and United States “Premium” grade quality, and it is shown that these engines vary considerably in the benefit they derive from the better classes of fuel. It is concluded that, in order to obtain the maximum benefit of a given anti-knock quality of fuel, an engine should be over-compressed and operated with retarded ignition at full throttle.

The characteristics of side-valve engines are given special consideration, and the desirability of restricting full throttle spark advance at high speed is mentioned.

Carburation requirements for good fuel utilization are also dealt with, and the effects of combustion chamber deposits are discussed.
The Design and Development of Heavy Haulage Vehicles
Authors: Burton C. E.
Published: June 2010

The regular transportation of heavy loads under off-the-road conditions was made possible with the advent of the six-wheeled type of heavy haulage vehicle. The development of the six-wheeler in Great Britain began in 1923 and the author was responsible for the design and development of the first prototype vehicle.

This paper shows in detail the design and development of the latest and largest British six-wheeler to date and some of the possibilities of this versatile type of vehicle which carries heavier loads than are normally carried on made-up roads, over rough ground and desert country under tropical conditions at relatively high speeds.

The development of this vehicle was to meet the specific requirements of the Iraq Petroleum Company in laying their 550 miles of pipe-line from the Mediterranean to Kirkuk in Iraq, which task was completed six months ahead of schedule.
Motor Vehicles in Hot Countries
Authors: Carruthers C. J. D.
Published: June 2010

During 1943–46 the author commanded the Experiments and Trials Wing of the Inspectorate of Mechanization, India Command.

The main function of this organization was to test, on proving grounds in North India, the suitability of each type of motor vehicle which was sent to India for operation in the tropics.

This paper, which is the result of the author's experiences during this work, deals with some of the conditions of climate and roads encountered in the tropics, their effects on the operation of motor vehicles, the special design features necessary to provide for them, and the practical tests necessary to determine whether those features were satisfactory.
Steering and Stability of Single-track Vehicles
Authors: Wilson-Jones R. A.
Published: June 2010

The author briefly states the elementary principles of equilibrium and claims that the stability of the conventional bicycle or motor cycle is automatic except at very low speeds. This is because the steering automatically turns in the direction in which the machine is leaning and returns to the straight ahead position when the machine is restored to the vertical. The achievement of these effects is largely due to the “trail” of the front wheel.

The causes of “steering roll” and “steering wobble” and the purpose of the inclination of the steering head, are examined, as are the effects of high and low mass centres and of the rider leaning with and against the machine.

It is shown how the elementary principles of steering apply to various types of vehicle, including single-track vehicles in which the necessary lateral force comes mainly from camber thrust rather than slip angle.

The results are given of experiments on varying amounts of “trail”, and a method of measuring slip angles is described which is applicable to motor cycles. Finally, a method of indicating the direction of the torque applied to the handlebars when entering, holding, and leaving a bend is described.
Automatic Transmissions in America
Authors: Chayne Charles A.
Published: June 2010

Since the internal-combustion engine was first adopted for automotive use, American industry has conducted a constant search for a transmission with infinitely variable ratio, fully automatic operation, and high efficiency.

The fully automatic transmission has now evolved into a unit providing greater safety and ease of operation for the driver. It is no longer considered novelty or luxury equipment in the passenger car and its value is rapidly becoming recognized in commercial applications.

Engineering research and development in the United States of America has been active in this search for two decades. The first approach was the development of friction, electrical, and hydraulic displacement drives, all of which resulted in bulky and heavy mechanisms inefficient and impractical in use. Then came the development of hydrodynamic drives, the fluid coupling, and the torque converter. Here, continual commercial successes have been made. The first use of the torque converter was in city service 'buses in 1934, replacing the manual shift transmission which was subjected to a gear shift every eleven seconds of its operation. In 1939, the first successful automatic passenger-car transmission, the Hydra-Matic, was produced. From that date onwards all competitive American passenger-car manufacturers followed in suit with their own designs. In many cases, the different transmissions have been mere re-arrangements of already proven designs, the features chosen representing the respective engineer-management judgement of the desirability of the various characteristics of known automatic transmissions. The extent of the field is evidence by the production of automatic transmissions in the United States of America, which in 1951 was 2,422,131 units.

While development work was progressing in the passenger car field, the field which offers the greatest promise of commercial rewards, extensive activity was also prevailing in the commercial and military fields. Here engineering research and development has led to the design and current production of automatic drives, using either the fluid coupling or torque converter, for use in highway and off-highway trucks, earth-moving equipment, cranes and hoists, railroad equipment, oil-well servicing and drilling equipment, and, in the logging industry, yarders and hauling equipment. Military applications are currently being made in all weights of tanks, trucks, and track-laying vehicles.

So it can be seen that the scope of the American field of automatic transmissions is large and the development has been extensive. It has an interesting history and the field shows promise of still further gains.
Ignition Interference with Television Reception
Authors: Ball A. H. , Nethercot W.
Published: June 2010

The spark-ignition circuit of the internal-combustion engine is the most widespread source of interference to short-wave radio and television services. This paper reviews the progress made in the measurement of the interference producing radiation and the development of remedial measures summarized in the relevant British Standards and Codes of Practice. The regulations for the control of ignition interference recently introduced by the Postmaster General are described and their implications discussed. The design, construction, and efficacy of suppression equipment, in particular suppression resistors for insertion in the high-tension part of the ignition circuit, are described in some detail.

The possible effect of resistors on engine performance is discussed and the results of tests under controlled conditions indicating negligible effect are given.

The results of extensive measurements of the magnitude of ignition interference on passenger cars and commercial vehicles are analysed and assessed in relation to the permissible limit imposed by the regulations. Estimates are given of the percentage of vehicles complying with the regulations by the adoption of the various methods of resistor suppression.

The MS. of this paper was received at the Institution on 10th July 1952, and in its revised form, as accepted by the Council for publication, on 1st January 1953. For the Minutes of the meeting in London, on 10th February 1953, at which this paper was presented, see p. 90.
Research and the Engineering Process, with Particular Reference to the Automobile Industry
Authors: Merritt H. E.
Published: June 2010

The paper represents a broad commentary on the development of research and of the part that it has played in the evolution of the engineering process.

The engineering process is the sequence of all the stages by which knowledge and experience of many kinds are brought together in order to lead to a final design.

To the age-old combination of craftsmanship and mechanical inventiveness is now added the application of the physical sciences. This third ingredient is becoming increasingly essential, and is based upon research. The various categories of research, and the places and manner in which they are best conducted, are briefly described, and the directions in which further research is required are provisionally classified.

The object of the paper is to promote discussion, with special reference to the requirements of the motor industry, with which the Motor Industry Research Association is coupled.

The MS. of this paper was first received at the Institution on 5th September 1952, and in its revised form, as accepted by the Council for publication, on 25th October 1952. For the Minutes of the meeting in London, on 9th December, 1952, at which this paper was presented, see p. 16.
An Investigation of Stresses in Public Service Vehicle Type Wheels
Authors: Fosberry R. A. C.
Published: June 2010

The causes of failure in wheel rims has been only recently investigated and this paper is a contribution dealing with public service vehicle type wheels.

Various types and sizes of wheel are considered, statically and dynamically, with differing tyre sizes. The results obtained with wire resistance strain gauges are claimed to be more reliable than those achieved by the deflexion method. Stresses in the critical parts of a wheel are produced by assimilating the forces which would be experienced in service, including bumps, corners, and braking.

The influence on wheels of acceleration on corners and deceleration due to braking is examined and results shown. Stress analysis of a wheel is only part of the design problem, since residual stresses induced during manufacture, the properties of the material and the order of severity of service conditions have also to be taken into account.

The investigation concludes with a comparison of a welded wheel and a riveted wheel, but the latter has received wider consideration. It is not claimed to be a complete investigation suitable for establishing a design procedure, but results obtained provide much useful information.
The Jaguar Engine
Authors: Heynes W. M.
Published: June 2010

This paper is a review of the design and characteristics of an overhead-camshaft, hemispherical head engine, particularly in respect to the production of an economical power unit for passenger car use.

The reasons for adoption of this particular design are discussed and the difficulties encountered during the development of these particular engines are mentioned.

An analysis of the engine on the test brake is given, and a comparison is made with contemporary engines.

Finally, a section is devoted to the further development of a basically touring car engine for high-speed competition events.

The MS. of this paper was received at the Institution on 27th February 1953. For the minutes of the meeting in London on 14th April 1953, at which this paper was presented, see p. 118.
The Charging Processes of Internal-combustion Engines with Special Reference to the Two-stroke Cycle
Authors: List Hans
Published: June 2010

The MS. of this paper was received at the Institution on 23rd November 1953. For the report of the meeting in London, at which this paper was presented, see p. 44.
The Application of Power Assistance to the Steering of Wheeled Vehicles
Authors: Heacock F. H. , Jeffery Harold
Published: June 2010

The object of this paper is to survey the rapidly broadening range of vehicle types to which power assisted steering is being fitted, to give descriptions of some of the various approaches to the problem of making such provision and to comment on particular features of systems using alternative installation layouts and/or different sources of power.

Emphasis has been given to the problems of applying power assistance to the steering of the General Service or Public Service classes of vehicle, since it is felt that in these spheres the higher road performance attainable with the aid of such assistance may give rise to operating troubles with designs that previously have proved satisfactory over a long period of development and usage.

Special purpose vehicles would normally be expected to go through a proving period, while the steering of private cars up to the limit of road adhesion is possible without power assistance.

It is considered that it is in recent months rather than in recent years, a marked practical interest in steering assistance has developed in Great Britain, and although this ground has been largely covered previously in published articles and particularly in American literature, some recapitulation should prove of interest and, it is hoped, of value, to those who, until a comparatively short time ago, had not given very serious thought to the likelihood of a more general demand arising, but who are now attempting to judge the strength of the present trend.

Brief remarks are made regarding the history and development of powered steering installations, but such observations that are made are not intended to present a full story.

The MS. of this paper was received at the Institution on 23rd December 1953, and in its revised form, as accepted for publication on 5th January 1954. For the Report of the meeting at which this paper was presented, see p. 94.
Experimental Investigations on the Braking Performance of Motor Vehicles
Authors: Starks H. J. H. , Lister R. D.
Published: June 2010

This paper contains the results of experimental investigations on the braking performance of different classes of road vehicle when new and as they are used on the roads. Measurements were made of the shortest braking distance obtainable on a dry surface and of the behaviour of cars during emergency braking on straight roads both when the brakes were properly adjusted and when they were deliberately put out of adjustment to simulate the condition of some braking systems observed on the road. The results confirmed earlier experiments with models but also showed that if the time interval between the front wheels locking and the rear wheels locking exceeds a certain critical value, this has an important influence on the behaviour of the braked car. Measurements are described on the braking performance of commercial vehicles and how this is affected by loading and by the characteristics of the braking system. Other investigations on the braking performance of public service vehicles, motor cycles, and motor-assisted cycles are also described. Certain discrepancies in the published figures for the braking performance of vehicles are discussed. The paper concludes with a summary of the braking problems which merit the attention of vehicle designers.
Street Lighting Performance
Authors: Ruff H. R. , Lambert G. K.
Published: June 2010

The object of traffic route lighting in Britain is to enable vehicles to traverse built-up areas in safety, without the need for head lights. The technique adopted is to project light on to the road to show its direction and features, and to reveal clearly obstacles and other road users in silhouette. To achieve this an average road brightness of 0·2 foot-lamberts without excessive diversity is adequate. Glare from the lighting must be controlled to avoid disturbing a driver's visual adaptation but mainly to minimize his discomfort.

A means of appraisal of the effectiveness of street lighting installations is described and applied to some installations. This should be of value to indicate which of the older installations are adequate and which need raising to a standard that affords an ample margin of safety without the use of head lights.

Since it is left to the discretion of drivers to use head lights when they need them, it is suggested that the limitation in mounting height on other roads be relaxed sufficiently to enable lanterns to project safely over the road in order to effect considerable improvement in lighting, particularly on tree-lined streets.
Analysis and Interpretation of Service Records
Authors: Wilford A. T.
Published: June 2010

The paper is concerned with records arising in the running and maintenance of a fleet of road passenger vehicles. Such data are inherently variable and unless this is appreciated much effort may be expended in seeking explanations of trends which are of a transient nature and of no real significance. It is necessary to discover the causes of the variability. In doing so it is often desirable to supplement the routine records by information derived from controlled tests; examples of such tests and their interpretation are given.

Records relating to failures and delays to vehicles in service are discussed and a system by which the level of failures is kept under close control is described. Fuel consumption records are then dealt with and the various factors which influence the figures are listed and dilated upon; particular mention is made of the effects of variations in temperature, loadings, traffic density, fuel and lubricating oil characteristics and ‘between-vehicle’ variations. Service tests other than those relating to fuel consumption also receive mention and a method for assessing engine life, employing the ‘Life Table’ technique as used in actuarial work is explained. The paper concludes by stating that if it succeeds in making both manufacturers and operators more aware of the inevitableness of variability it will have achieved its object.
Assessment of Car and Fuel Factors Affecting Vapour Locking Tendency
Authors: Sheppard G. F. , Withers J. G.
Published: June 2010

‘Vapour lock’ is a term used to describe an adverse change in the performance of the fuel system resulting from the evolution of vapour from the fuel. It may occur anywhere in the fuel system although petrol pump vapour lock is generally the most serious. The most common form of this trouble is that which arises when attempts are made to re-start a car which has been stationary for a few minutes, after having been previously driven at sustained high speed.

The mechanism of vapour lock is shown to depend both upon the amount of vapour formed and the ability of the fuel system to handle vapour, but the greatest improvements are likely to be made in reducing the amount of fuel vapour formed. The effects of temperature, pressure, and fuel volatility on vapour formation are discussed, including the conflicting volatility requirements for freedom from vapour lock on the one hand, and good starting and warm-up characteristics on the other.

It is shown that distillation and vapour pressure characteristics are not suitable criteria for quality control purposes, and that only by the laboratory determination of vapour/liquid ratio (V/L) versus temperature relations can a proper estimate of fuel vapour locking tendency be obtained. Laboratory apparatus for determining of V/L ratios is described, and results for some fuel combinations are presented.

The various driving conditions encountered in service are discussed in relation to their effects upon vapour locking tendency. Open-road driving at full throttle followed by a stationary ‘soaking period’, during which the under-bonnet temperatures rise to maximum values, is a very severe condition, but hill climbing or city traffic conditions may be just as severe. A full throttle soak-test method for the determination of the volatility tolerance of cars on the road, making use of a double series of reference fuels, is described; it is shown how the results may be interpreted in terms of the ambient temperature for freedom from vapour lock using any given fuel. A description is also given of a simplified road technique using a single series of reference fuels. This test technique requires no vehicle instrumentation, and a predetermined V/L ratio framework may be used to interpret the results.
Matching a Diesel Engine to Light Road Vehicles
Authors: Vulliamy N. M. F.
Published: June 2010

Reference to early use of Diesel engines in cars, etc., includes remarks on the application of heavier commercial transport engines. A list of ways in which the small Diesel has to compare more closely with the established petrol engine other than in fuel economy is followed by a description of experiments on a 1 1/2-litre four-cylinder design which fits a number of popular types of vehicle. Various difficulties met with are mentioned. In particular, valve gear and injection pumps required special attention. Specific outputs comparable and even higher than those of some contemporary petrol engines of the lower priced cars were obtained, but not without some noise and smoke. Graphs and tables show engine performance and data of injection processes and valve gear for maintenance of volumetric efficiency.

It is shown that the Diesel and petrol engine size is similar, as are torque curves throughout the speed range. An automatic injection advance is necessary for reducing noise at low speeds and to keep performance up at high speed. Some road test figures are given; when the engine was installed in a typical 1 1/2-litre petrol car the effect was encouraging so far as performance and fuel consumption were concerned. There was room for improvement in engine noise. Exterior noise will require reduction by engine modification. Cold starting is an important problem and it is desirable to avoid the use of expensive aids.

There is a reasonable expectation that the Diesel will be made attractive. Developments in injection pumps and possibly fuel will assist.