As used in automotive applications the internal combustion engine is woefully inefficient. Many gasoline race engines can claim up to 35% thermal efficiency at specific speeds and loads, but a figure of 25% – even as low as 20% overall – may be more realistic on the track. The fact is that the opening of the intake and exhaust valves by mechanical methods is rarely anywhere near that for optimum performance, largely because of transient conditions and the use of the throttle to...
I would guess that very few of those who handle cams – in that they either buy them or install them, or have some form of interaction with them in any way – have ever thought about the actual profile of the cam and the way it is generated. Sure, enthusiasts regularly talk about cam timing and lift, or even about valve lash or ‘lobe separation’, but in consideration of how such timing and lift is achieved in the practical sense I’ll bet that only a tiny fraction...
Isn’t it always the case that when you think you have designed the best cam profile ever – at least in your opinion – somebody always wants it smaller, lighter and/or even cheaper to manufacture? Is it little wonder then that when everybody else is looking at magnesium cylinder blocks, metal composite con rods or ceramic valvetrain parts, the camshaft designer is looking to save, what, a few grammes? The problem with the camshaft is that other than tinker with the profile...
Much has already been written in these columns about the technicalities of cam design and manufacture. But unless the component is properly installed in the engine so that the intake and exhaust valves are accurately phased to the motion of the piston then much of the effort involved in designing the cam may be completely lost. Rather like a stand-up comedian, when it comes to speaking of camshafts, timing is everything. For most applications I guess it is safest to suggest that, when...
In a recent poll of Britain’s sexiest fictional characters, despite it being dominated almost exclusively by men, the top slot was, unsurprisingly, James Bond. The creation of author Ian Fleming, Bond could handle multiple, often complex situations and therefore, it is thought, being in control of the situation, endeared himself to the opposite sex. Described as a ‘smooth operator’ this is indeed the description any designer would wish also to be applied to the profile of...