As most race engines are now of the four-stroke multi-cylinder variety, the vast majority of con rods designed and manufactured for racing are of the split type. This means having a reliable means of holding the two parts of the rod together with sufficient pre-load, and this is taken care of by threaded fasteners. There are two options here. The first and most common method is to use a bolt. The second is to install a stud, usually into the rod, and to provide the load by tightening a...
When I think back to when I was first introduced to competitive motorsport - rather more years ago now than I care to remember - I wince now at some the things we used to do. At the time, it was very much a 'make do and mend' attitude, and the amateur weekend designer/racer would often spend more of his time seeking that certain part of the right size or shape to support his backyard vehicle build. A common part might be, say, a top or bottom radiator hose. If money was not a...
In previous articles on oil drillings, nose-fed oil galleries have been discussed. This is not a new concept. However, the drillings used in a modern race engine with significant main bearing/crankpin overlap are far removed from those used in the comparatively long-stroke crankshafts without overlap. For a recent article on crankshafts for Race Engine Technology magazine, crankshaft suppliers revealed that the proportion of their racing crankshaft business which has nose-fed oil galleries...
If your car has ever broken down you'll know it can be both a humiliating and humbling experience, especially if a little prior warning could have rescued the situation or at least minimised its impact and allowed you to get back to a place of refuge for the problem to be fixed. Or worse still, if you're stuck beside the side of the track or special stage knowing that a minor issue could be cured and you could be on your way, and in with a chance of a good placing but for a want of...
The previous article on this subject described the concepts and decisions to be taken when applying a wet liner, and concerned the choice between top, bottom or mid-stop liner. Some basics were shared on the advantages of each one, and it was mentioned that a number of secondary engineering decisions need to be taken to establish the final design. This follow-up article will provide some more insight into these secondary decisions. Let us take a closer look at some of those decision areas:...