Archive

Even after more than 30 years in the engine business, the bearing systems in modern internal combustion engine still amaze me. Made from a mixture of aluminium and tin on a steel backing (for bi-metallic examples) or a mixture of copper, silicon and nickel topped off with an aluminium-tin overlayer, even after many hours of running, after stripping the engine I have seen bearings as good as new. And of course this is what the designer is aiming for because in theory, once rotating, the...

I suppose you could say that the valvetrain in any engine is a bit like my grown-up family. So long as everyone away from home stays in contact with the matriarch, all is well. However, as soon as that contact is lost - a late birthday card, for instance, or a promise to phone not honoured - then there are, shall we say, consequences. The same can certainly be said of the valvetrain, for when components in the system lose contact with each other the consequences can be more than simple...

The previous article on thrust face design of con rods was published more than a year ago. In this belated follow-up, we will look at the reasons why certain features are employed. One problem with thrust bearings is the fact that, in their simplest form, they comprise a stationary disc in sliding contact with a moving disc. If the plates remain a set distance apart, they do not generate any oil film pressure and so cannot act as a bearing. It is only by the relative movement of the...