A new concept from the French Surface preparation and coating specialist HEF promises to enhance performance at the cam/tappet interface by altering surface micro-topography. In high pressure applications the lubricant film separating two surfaces can be so thin it is little deeper than surface roughness, even where the components have been super-finished. “Clearly therefore micro-topography of surfaces can have a great influence on performance,” remarks HEF R&D specialist...
The heart of any internal combustion gasoline engine just simply has to be the camshaft and the valve mechanism it controls. Designed to maximise the amount of air entering the cylinder at a range of engine speeds, it is often perhaps the first port of call when seeking to improve engine performance. In theory, and in an ideal world, the inlet valve should open to its full lift precisely at piston top dead centre and then close again when the piston next comes to rest at bottom dead...
It is perhaps not widely appreciated that the stand-up comic and a camshaft have much in common. Both rely on split second delivery: the punch line in the case of the former while the latter ensures that the engine valves are opened and closed to a predetermined plan. If the punch line is too early or too late an audience who might otherwise be rolling around in the isles could be on the point of getting up and walking out.A similar metaphorical disaster could be awaiting the engine....