Friction is the enemy of horsepower. It’s a simple enough mantra, but in order to reduce it in the internal combustion engine a full understanding of the tribology at each mating surface is essential. The friction in the ring pack and cylinder bore is, as a rule, by far the greatest, but that in the valvetrain mechanism is generally next on the list, especially so as engine speed falls. For the vast majority of race engines the direct acting system (or DAMB - Direct Acting Mechanical...
Rolling element bearings continue to develop to meet the needs of ever-increasing speeds and loads. We might expect that there would be few applications of engineering coatings to these components, but there is a growing number of applications for which we might consider various coating options. A few months ago, in an article on plasma and thermally sprayed ceramic coatings, I wrote about the use of electrically insulating coatings being applied to the outer races of rolling element...
The con rod is something that almost all piston engines have in common, and certainly all successful modern racing piston engines rely on these components to link the piston and crankshaft. There are some obvious visual differences between many racing con rods and their counterparts in a passenger car engine, although their roles are the same, as is the type of material used for their manufacture. As with many components in a modern road engine, economics play just as important a role as...
It may have escaped the notice of the casual observer but the emphasis of modern vehicle design/development is not so much about style or performance (these are very much a given today) but in the management of engine heat. Thus turbochargers, once the dream of boy racers the world over, are now a common sight and will convert the otherwise wasted exhaust heat energy into useful work by pressurising the intake charge. Adding a further turbine downstream of the first - turbo-compounding we...
Crankshaft counterweights are required on certain engine configurations to allow the engine to run without excessive rocking couples; cruciform V8 crankshafts are an example of this. Other engine configurations can run happily without counterweighting of any type to eliminate rocking couples, but they often require some counterweighting in order to maintain bearing loads within reasonable limits. Bearing loads not only have affect engine reliability, but also on friction. Some engineers...