Many of us will be aware that the con rod bolt is very often the most highly stressed fastener in any race engine. Not only is it highly stressed but if a rod bolt fails then the consequences can be catastrophic for the whole engine. I have seen engines where there has been a rod bolt failure, and very little of any real value could be used again. Thankfully though, by using careful tightening procedures and the correct bolt for the application, rod bolt failures are relatively rare. The...
It is an inescapable fact that pressure charging the intake air of an internal combustion engine invariably increases the temperature of that charge. The degree to which the temperature increases is essentially a function of the type of compression that takes place (adiabatic, isothermal) and therefore the efficiency of the compressor. The turbocharger, with its centrifugal compressor, accelerates the charge very quickly and then diffuses it slightly slower to convert the velocity energy...
In the previous article, the subject of crankshaft grinding was discussed. In addition to the perils of grinding incorrectly in terms of ‘grinding cracks’, there is evidence to suggest that the direction of travel of the workpiece relative to the grinding wheel is also significant. When cylindrical grinding takes place, the grinding wheel, which is usually much larger than the journal or crankpin being ground, rotates at a much higher speed than the workpiece. The ratio of...
Those of you who enjoy historic motorsport as well as more modern automotive activities will appreciate that engine spark-ignition systems have come a long way over the years. From the inefficient magneto systems of the early years – which were fine so long as you could generate sufficient energy at cranking speeds – through single-coil battery systems to multiple coil-on-plug devices, the principles involved in generating a high voltage to the spark plug may not have changed,...
In this issue’s article on Engine Structure I want to look more closely at the cylinder liner and its ability to play a significant role in the overall cooling system in race engines. Despite its passive role historically, this rather simple component has grown in significance in the engine’s cooling system – especially the liner’s exterior, rather than its interior, since guiding the piston requires a more or less round shape there. Where the influence on the cooling...