Whenever we mention O-rings everyone knows what we mean – those small black rubber rings, the simplest gaskets you can get. Or so we assume. Since the O-ring was first developed, a long time ago now, enormous strides have been made in its engineering. Ongoing material development has increased its range of applications, while better production toolings and processes have improved its dimensional stability and mechanical robustness. An O-ring is one of the most robust sealing concepts,...
Exhaust systems can sometimes be a ‘forgotten component’ in a racing powertrain – some people pay them scant attention when it comes to performance, although they can offer real advantages. In NASCAR, the rules have been stable for a long time, but this does not mean exhaust development has come to a halt. With the introduction by NASCAR of the Car of Tomorrow (CoT) for the top-level Sprint Cup series, and the various developments that have followed, teams have had to look...
In a bolted joint, the design of the fasteners is responsible for the proportion of the service load borne by the fastener, and the theoretical ratio of torque or tightening angle to load is influenced strongly by the dimensions of the nuts, bolts and studs and by the coefficient of friction acting between them. Much effort is put into fastener design, but washers are often neglected in terms of design, although they can have a very positive effect on the reliability of the system. As is...
The function of the fuel supply system in the spark-ignition engine is simple: to supply the correct volume of fuel at the correct pressure appropriate to the method of engine fuelling used. In the case of a carburettor, for instance, this might mean a fuel pressure of no more than 1.5-2 psi (10-15 kPa) pumping the fuel into the carburettor float chamber, from which the fuel will be sucked into the intake air stream. A simple, engine mounted, cam-actuated mechanical lift pump using an...
The idea of boosting engine performance by increasing the density of the intake charge is nothing new. Compensating for poorly designed intake systems may have been the reasoning for their use in the late 19th/early 20th century period, but these days the science of pressure charging the internal combustion engine is not just about power density but increasingly the energy efficiency as well. For simple power density in terms of kilowatts per kilogramme of engine weight, a gas turbine unit...