Where a fastener's dimensions are tightly controlled, and where there is access to both ends of the fastener, it is common practice to measure bolt elongation as a measure of fastener pre-load; the preferred method of tightening con rod bolts uses this method. However, there are many occasions where access to both ends of the bolt is impossible, and we have to choose one of the other methods at our disposal. In previous articles we have looked at some of the other methods, such as...
It has often been said that 'racing improves the breed'. While this may have been true half-a-century ago - the development of the disc brake perhaps being one example - these days the thrust of new technology is definitely the other way around, and there's no finer example of this than the growing use of direct injection in the gasoline engine. But while the roadcar boys need it for the extra control it affords - primarily in the operational areas of 'cold start', fuel...
Arguably the most critical part of the interface between man and machine is that of the engine throttle. Designed to restrict the flow of air to the engine by balancing the rate of working of our spark ignition unit against that demanded by the driver, the throttle has evolved and matured over the history of motorsport. In essence, the options available over this time have been barrel, butterfly or slide, and although slide throttles were very popular at one time their propensity to stick...
Oil coolers are a vital part of any racecar lubrication system and have to meet a number of exacting design criteria. In many applications, especially where aerodynamic performance is an important part of overall performance, the sizing of coolers can have a big impact on aerodynamic efficiency. The larger the cooler, the larger the inlets required and the greater the drag; the result being that safety margins in the cooling system can be pared back to a minimum. This means that any...
The piston rings used in a race engine are primarily a seal, controlling the flow of oil upwards into the combustion chamber and the flow of blow-by gases into the crankcase. We don't want oil to get into the combustion chamber; in large enough quantities it can cause combustion problems, but even in small quantities where the oil is burned, the loss of oil can be serious, causing us to carry a supply of oil with us. On the road, this isn't a huge problem. In a race though, it means...