Development of the Poppet Type Exhaust Valve in the Internal Combustion Engine: Part I 1860–1930

Abstract

At a very early stage in the development of the internal combustion (IC) engine, poppet valves became the standard way of controlling the flow of the fuel/air mixture into the cylinder and the flow of exhaust gases out. Of the two valves, inlet and exhaust, the latter is more susceptible to failure. Exhaust valves are affected by creep, high temperature fatigue, and valve ‘burning’ from corrosion by the exhaust environment. As engine outputs increased, valve temperatures also increased and changes to fuel specification worsened the risk of corrosion. Initially, valve reliability was compromised by the limited range of alloys that were available, but the lack of scientific understanding of alloys also hindered development. After 1910, the mass-production automobile stimulated the need for better design and materials. Key advances were made in WWI when the Royal Aircraft Establishment investigated the first stainless steels for valves and the technique of cooling hollow valves using a sealed-in fluid. During and after WWI, work by Ricardo and others began to reveal the importance of octane rating, and towards the end of the 1920s fuels incorporating tetraethyl lead began to be utilized in American Naval aircraft, but this was the exception. In the automobile industry in the 1920s, much work was done on valve design. In this period both aircraft and automobile engines used Silchrome, a martensitic stainless steel containing silicon as well chromium, as the standard exhaust valve alloy. Silchrome had reasonable high-temperature strength and good resistance to the type of high-temperature corrosion from the unleaded fuels then in common use.

Keywords:

• internal combustion engines
• poppet valves
• valve alloys
• fuels
• Ricardo
• RAE
• Aitcheson

Additional information

Notes on contributors

Fred Starr

F. Starr graduated in Metallurgy in 1966 and joined British Gas, becoming their principal investigator of steam reforming plants failures. From 1974 he ran a group to develop high-temperature alloys for advanced coal and oil gasification processes. Some of this work is covered in his semi-historical survey ‘The Engineering Science of High Temperature Corrosion’, a lecture given at the University of Surrey. From the 1980s onwards he initiated programmes dealing with Stirling Engines, Closed Cycle and Inverted Cycle Gas Turbines, and the Rotary Vee two-stroke. After leaving British Gas, in 1996, his main work has been on power plant operation. His last formal job was with the European Commission’s Institute for Energy, where as a ‘Visiting Scientist’ he was responsible for the design of a plant to produce hydrogen and electricity from coal. In terms of industrial history, his focus is on steam, IC and gas turbine development, using modern knowledge to highlight the background to engine designs and breakthroughs. He achieved a life-long ambition in 2007 in gaining a doctorate with his thesis on ‘The Development of an Expert System for Failure Analysis of Power Plant Components’.

Correspondence to: Fred Starr. Email: [email protected]