There are a number of reasons why we might want to improve the level of surface finish on components for race engines and transmissions, but the chief among these are reliability and friction. By improving the level of surface finish, we generally mean reducing the level of roughness. The effect of reducing roughness on component reliability is well known, and has been quantified for a range of surface finishes from rough-cast, through machined and ground finishes to 'mirror'...
In the pages of Race Engine Technology and in these short web articles, there have been numerous mentions of the significant benefits of having residual compressive stresses present at the surface of a component. To recap, incorporating a method (or methods) of introducing residual compressive stress at a component's surface is, in general, likely to improve the endurance limit of a component loaded in bending or torsion. Given that there are very few components that are loaded in a...
There are a great number of components in the race engine that need a hard, wear-resistant surface. Crankshafts, camshafts, cam followers, gears, sprockets, spindles and pump shafts are some example of components that are regularly treated in some way to increase the hardness of the surface. In some cases, there is a requirement that the part has a high level of strength throughout, and such components which are through-hardened. Camshafts, and cam followers are commonly produced in both...
There are often lots of shiny parts in a race engine, and some companies produce parts of a high surface finish as a sales point; there is a perception by some that a polished part is better quality and therefore has an inherently higher value. There are very good reasons though why some parts benefit from having a high level of surface finish. One only has to look at the data presented in engineering textbooks on the subject of fatigue strength and cyclic loading to realise that improving...
There is a vast array of metallic materials of all kinds whose mechanical properties are improved by heat treatment. Steels are commonly raised to high temperatures, quenched and subsequently tempered by raising the temperature to a carefully controlled level and maintained there for a known amount of time; aluminium and titanium alloys are often solution-treated by heating to a given temperature before quenching and age-hardening by heating. In the case of most steels after quenching, the...