Those of you who have read previous articles of mine on surface treatments may have noted a point that I have continually stressed – that residual compressive stresses can have a very beneficial effect on a component’s endurance. One of the most popular processes for doing this is controlled shot-peening. Many engineers are aware of the benefits of controlled shot-peening, but there has been a lack of in-depth understanding of where the benefits come from, and how the process can...
Pressure sensors are an integral part of advanced engine testing systems, particularly those used to measure in-cylinder combustion pressures. These provide an invaluable insight into the efficiency of the combustion process and are a vital tool for engine calibration and testing. However, the conditions present in many bespoke race engines can prove problematic for some sensor types, due to factors such as very high combustion pressures and vibrations caused by high rates of valvetrain...
Regardless of the racing series, almost every racecar in the world will feature a clutch. However, the friction materials used in these clutches will differ radically depending on the torque and power delivery characteristics of the engine. So what are the materials available and how to they vary? Organic So-called ‘organic’ clutches have been around for the best part of 50 years. Organic is something of an outmoded term now, as it harks back to when asbestos was used in the...
Valve springs are often the most highly stressed parts in any race engine. While some types of race engine don’t have valve springs – two-stroke, Wankel, four-stroke desmodromic or four-stroke with pneumatic valve return – most of the race engines we encounter will be equipped with some form of wire spring. For modern engines valve springs will generally be the familiar helical spring. In their unending quest to make the engine perform better through improved breathing,...
In the previous article on the advances in rapid prototyping materials and methods, some possible applications were mentioned, especially for exhausts. Laser-sintered exhaust components have been displayed at trade shows for several years now and there are exhaust companies who have used the method to produce real parts for a few years in both high-temperature materials such as Inconel but also titanium. There are of course other applications for this technology and the increasing range of...