The benefits of injecting fuel directly into the cylinder have been understood for many years, but so too have the technical difficulties. Better volumetric efficiency and the ability to inject the fuel exactly where it is wanted at precisely the correct time in the engine cycle are the upsides. The physical difficulties of installing the injector, the fuel pressures needed and the temperature of the injector tip are some of the downsides. As long ago as the early to mid-1950s, Mercedes...
If you’ve ever examined the contents of the dirty side of the air filter of your daily transport you don’t need me to emphasise the importance of the filter on the engine air intake. Grit, dead leaves and even quite large insects can all easily be found scattered inside the entrance to the airbox, so in contrast to the ‘clean’ zone at the inner side of the filter, if ever there was a case for including an air filter on all engines – particularly those for...
Oil aeration can be a major problem in high-revving race engines. The presence of oil bubbles in significant quantities in an engine’s oil can lead to pressure loss and damaging cavitation in the oil pump. Controlling the issue is a multi-faceted task, requiring that all aspects of an engine’s oil system are optimised to combat it. The sump, oil pump, oil tank and even the oil itself can be engineered to minimise aeration, and thus improve both and engine’s performance and...
In its most basic form the piston pin is simply a piece of round bar. However, very few engines – other than very basic, low-budget units – are equipped with solid gudgeon pins as standard. Of course, in the rarified world of racing, there are some applications where conventional technology won’t suffice, and we can also find solid piston pins in some tractor pull engines. It is usual though for engines in production cars and motorcycles, and almost all race engines, to be...
Carburising and nitrocarburising are types of surface hardening processes that rely on diffusion to change the composition of the surface of metallic parts. The names suggest the elements involved in the diffusion process – in the carburising process, the percentage of carbon in the surface of the component is increased, and in nitrocarburising, both carbon and nitrogen are added to the surface. Both treatments are a very good way not only of hardening the surface of a component but...