In these financially straitened times, the fuel consumption of engines has taken on a new level of importance - not, I hasten to add, to minimise the production of carbon dioxide and its environmental impact on the world but, within motorsport, the simple realisation that every unnecessary litre of fuel weighing 0.75 kg, is 0.75 kg too much. Irrespective of the current financial climate therefore, minimising fuel usage seems to make so much more sense. That being the case, in any engine...
With the exception of off-road racers competing in events such as the Dakar Rally, it is unlikely that any type of competition vehicle is required to deal with as varied a range of conditions as a WRC rally car. Ten years or so ago, WRC cars were far removed from any other type of current rally machinery, but with introduction of new rules in 2006 and Super 2000-based regulations in 2011, the complexity of the designs manufacturers can employ has been greatly reduced. In relation to...
The pushrod valvetrain, while having great advantages for engine packaging, has the distinct disadvantage of not having a very direct connection between cam and valve, as is the case with overhead cam (OHC) engines. Even in the case where finger followers with roller bearings are used, the stiffness of the system is higher than is typically the case with an overhead valve (pushrod) system. As has been stated in previous RET-Monitor articles on pushrods, efforts are always being made to...
Who could imagine using the same set of valve springs for more than two years in a nitrous-infused 565 cu in V8 engine that competes in the quarter-mile on water? Wayne Gaskamp has been able to accomplish just that with his 1800-plus hp engine that propels Mike DeClark's F Bomb drag boat in two categories of National Jet Boat Association (NJBA) competition, the seven-second and unblown fuel jet classes. The NexTek-polished Manley triple springs of lightweight tool steel have been...
In developing a race engine it is common to evolve valve-lift profiles constantly to improve the 'breathing' of the engine. The aim is to increase volumetric efficiency or, more precisely, to increased the trapped mass of fresh, unburned charge. In the case of race engines this often leads to the use of more 'aggressive' cam profiles. By 'aggression' in the case of valve-lift profiles, this means higher accelerations and the derivative of acceleration with respect to...