In motorsport, the four-stroke engine is dominant in terms of numbers, and the vast majority of them use what we would describe as conventional shell bearings for both crankshaft main bearings and big ends. The most common method used to ensure proper location of these bearings and to prevent rotation is a combination of proper preload and tags (or tangs) which locate in precisely machined slots in the con rod big-end bore. This method is also that used by most production engines. There...
There have been brief mentions in the pages of Race Engine Technology of the possibility of coating the big-end bore of con rods directly with the soft metal bearing coatings that we find on the surface of bearing shells. Further mentions have appeared in previous RET-Monitor articles on the subjects of coatings and con rods. Many years ago, this was indeed the way it was done, with the bearings manually 'scraped' by hand to achieve the correct size. Progress in the production of...
The forces acting on the con rod are considerable, and the components to which they are attached are surprisingly flexible, although they may not appear so when you pick up a component such as crankshaft. The deflections of the crankshaft (bending and torsion) and the con rod (torsion) give rise to a tendency for there to be some axial force on the con rod trying to force it one way or the other parallel to the crankshaft axis. In providing adequate lubrication (and therefore very low...
There is a natural tendency for race engineers to try to improve the performance of engines - after all, this is precisely what many of us are paid to do. There are different ways to achieve this goal, but the primary focus for many of us is to increase the amount of energy converted from chemical energy in the fuel into kinetic energy. The rules impose various limits on us but, in general, if we are constrained on engine swept displacement as one of our development strategies, we will...
After inventing the internal combustion engine, it became clear that man always wanted more power, not only for racing and record-breaking, but also for his road vehicles. Today we have road-going production motorcycles that are more powerful than their Grand Prix counterparts of 15 years ago. The merits of using multiple cylinders are well known, and to make compact engines with larger numbers of cylinders, 'vee' engines are a good solution. Most bespoke race vee engines have two...