Design and Development of Exhaust Valves for Internal Combustion Engines

ABSTRACT

The development of the mushroom type exhaust valve for aircraft and automotive reciprocating engines is, to date, the longest running set of programmes involving the use of high temperature materials in an engineering application. Nevertheless, because of shortcomings in the materials which were available at any one time, the design of valves had to become quite sophisticated.

It is shown that changes in the type of alloy used for exhaust valves were governed by changes in the composition of the fuels which came into use at various periods. These fuel changes were generally introduced to improve engine performance. But, more recently, the changes in fuel compositions have been aimed at giving cleaner and less toxic exhaust emissions.

To a very large extent both the changes to the fuel and the exhaust valves seem have been introduced without much scientific insight. In particular the quest for improvements in valve design and valve alloys was quite empirical. Only now are we in a position to begin to identify the science behind these developments.

Although early mass production vehicles, such as the Model T, had used rather clever designs of exhaust valves, formal investigations of the exhaust valve technology only began during the First World War, when the aim was to increase the reliability of aircraft engines. Development in the 1920s was in influenced by the need for increased power as well as reliability. Vital to this was the introduction of fuels containing tetraethyl lead. Valve burning became a critical issue, which was kept under control using sodium cooling and through the use of nickel and cobalt alloys. This allowed the development of some very advanced aircraft engines, including the Rolls Royce Merlin, the Pratt Whitney Double Wasp, and the Daimler Benz DB 601.

The coming of the jet engine ended work in the aircraft industry and Governmental organisations. So, from 1950, the automotive sector began to dominate valve development, with price and reliability being the critical issues. But sophisticated valve alloys were and are needed for sports car application. However, in the latter part of the 20th Century, the introduction of low lead fuels gave the engine manufacturers a new set of problems, and although solutions have been found, the reasons for success are still obscure.

To summarise, the paper focuses on the key developments in design of exhaust valves and the materials from which they are fabricated. The paper also indicates how and why fuels have changed in composition, and takes a critical look at the design of some important wartime aero engines.

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Ancient Egyptian Tool Technology

ABSTRACT

This paper examines the development of tool technology in Egypt over the period 4000 BC to 30 BC. During this period the development of tools in Egypt was hardly influenced by external developments. At the end of this period, tools - especially of iron - were introduced from Italy and Greece and there ceased to be an identifiable character to tool development in Egypt.

The Paper is in three parts:

1. The first part deals with the environmental and social conditions which enabled the flourishing of practical and artistic activities.
2. The second part deals with the materials used for tools. These include stone, wood and ivory, copper and bronze and iron.
3. The third part deals with the use of these tools in the following activities: brick making, woodworking, stone working, agriculture and hunting, mummification and personal hygiene and working leather and fabric.

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John Scott Russell

ABSTRACT

John Scott Russell’s major contributions were all at the interface between science and technology – wave theory, steam engines, ship structure, organisations that established the professional credentials of engineers and naval architects, naval and national education.

As a shipbuilder his longitudinal structure increased the size and load carrying ability of ships, enabling them to incorporate big engines, heavy armour and turrets. He was an early advocate of ironclads. He built strong ships and proved his credentials as a structural engineer with the Great Eastern.

He also produced the 'Great Eastern of roofs', the immense Vienna Exhibition rotunda of 1873, with a 360 feet clear span, and the Great Eastern of books in The Modern System of Naval Architecture for Commerce and War a massive study which was priced at 40 guineas.

Always short of capital, dependant on the funds of others, Russell overtraded on his main asset, his talent. He attempted too much, spreading his intellectual resources too thin and when his shipbuilding career began to unravel, he lacked the reserves to ride the waves of economic activity. Furthermore he was not quite a gentleman, never rich enough to ignore the chance of making money, too hungry, too clever, too pushy and too ambitious. The negative side his ambition cost him the chance to star in the Great Exhibition; Russell’s manner always grated, he made enemies and they took any opportunity to demean him. He was not able to take up his intended presidency of the ICE. As a result he died without the usual honours, Brunel turned down a knighthood - Russell was never offered one.

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Patents or Piracy? Protecting invention in the nineteenth century

ABSTRACT

The mid nineteenth century inventor faced a number of dilemmas. Should a new invention be publicized for the common good even if that very disclosure then pre-empted any possibility of patenting it? Would the costs of securing a patent and then defending it in court litigation be greater than any profits it might eventually bring? Was it worth patenting a new device just to reduce the risk of foreign piracy if it were then displayed at an international exhibition?

This paper considers how the temptation to maintain secrecy over inventions was overcome by two of the great transitions for the Victorian inventor: the rise of the international exhibition, and a radical liberalization of patent law. I show how these two phenomena were inter-related.

While the Great Exhibition of 1851 was an unprecedented spectacle of British engineering, it also saw a near boycott by many inventors who could endure neither the cost nor the lengthy bureaucracy involved in patent protection. As a result of the pre-Exhibition stand-off, exhibitors at first won temporary protection for the duration of the exhibition and then eventually the1852 Patent Law Amendment Act that brought longer-term legal protection within the reach of the humble artisan.

Nevertheless, perils still lay in store for the unwary inventor. Alexander Graham Bell safely secured a US patent for his telephone before he exhibited it at the Philadelphia Centennial Exhibition in 1876. But Sir William Thomson’s public demonstration of it at a Glasgow meeting of the BAAS in nearly proved fatal to the UK patent that Bell secured only later that year. The paper concludes by showing how legal changes during the 1880 established the principle that public display of an invention would not necessarily constitute disqualifying ‘prior disclosure’ for the purposes of patent protection. Such marked a turning point in the history of industrial piracy and secrecy

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Equipping HMS Erebus and HMS Terror 1845

ABSTRACT

In the 1840’s steam and iron was revolutionising ship construction. HMS Erebus and HMS Terror, originally ‘bomb ships’, were used as polar exploration ships. In 1845 they were extensively modified for use by the Franklin Expedition. As soon as they were completed, they sailed and were never seen again, so these modifications are little known today. The paper describes them and explains their significance in 19th century shipbuilding. Many of the leading engineers of the day collaborated in these modifications including Oliver Lang, Master Shipwright at Woolwich Dockyard, the firm of Maudslay, Sons, & Field, Robert Stephenson, Francis Pettit Smith, the inventor of the propeller and the obscure father and son team of James and John Fraser, who made cookers, heating boilers and stills. It reviews the principle modifications, which include:

• Ex-railway locomotive engines fitted as auxiliary power units with telescopic funnels.
• Smith propellers installed in wells so that the propellers could be uncoupled and drawn up into the ship to reduce the risk of ice damage and water drag.
• Modifications to enable the ships to overwinter in ice including retractable wooden protection for their rigging.
• Iron-reinforced bows.
• Massive strengthening of the ships, including diagonally cross-planked decks, doubled wooden hulls separated by tar-paper and extensive use of iron fittings for reinforcement..
• A steam heating system using Fraser’s ‘patent annular boiler’, linked to the ships' galleys, which not only heated the ships but also provided distilled water for the engines and for the crew to drink.

Many of these fittings were highly innovative and used for the first time on these ships. The firm of Fraser is also discussed – widely respected at the time but forgotten now as their ingenuity was directed towards a technological blind alley.

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Artifacts at the Institution of Civil Engineers

ABSTRACT

This paper focuses on a single building profession (the ICE) and considers how the institutional building located in Great George Street, London, visually represents the authority of the profession.

Buildings are mute physical objects that nevertheless can underwrite the identity of the organisations they house. Some of the appurtenances associated with a profession include a large headquarters building or council chamber, often located in a prestigious part of town.

Part of the paper explores what the architectural imagery and construction of the ICE headquarters building reveals about the social and cultural context of the engineering profession. Many professional institutional buildings contain ‘paraphernalia’ – marble busts, oil painting, medallions, medals, silver plate, gilt cups, new seals and candlesticks, enormous chandeliers etc. – that have been accumulated and arranged over a number years. The paper goes on to consider what such embellishments say about the profession.

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