The previous article in the RET-Monitor section on crankshafts introduced the concept of damping the torsional vibration of the crankshaft. We discussed the most common form of commercially available damper currently supplied for racing – the inertia damper. Dampers with multiple damping masses can offer a further improvement by damping vibrations across a wider frequency range, but the advantage of the multi-mass dampers (usually two masses) is really confined to roadcars, where the...
One of the main points to consider when designing a cranktrain, or making significant modifications to any of the parts of the cranktrain, is that of vibration – and, most important, torsional vibration. There can be significant mechanical damage associated with cranktrain torsional vibrations; when this occurs, stresses are far in excess of those anticipated during normal operation, and it is not uncommon for crankshafts to break, or for problems to be ‘transmitted’ to the...
Crankshafts are at the heart of any race engine (apart from a handful of examples of successful Wankel rotary units). As we strive to obtain more from our race engines – whether it be more performance, faster transient response or improved fuel economy – there is pressure for the existing crankshaft to perform at higher speed, under extra load, or for a new design to be conceived that is lighter and has lower inertia. There are a number of ways to optimise any engine component....
For anyone who hasn’t seen the Nissan DeltaWing car, you would do well to look it up, as there can have be few more adventurous car designs in recent times. This was no rolling concept car, but raced at Le Mans. Its ethos was very ambitious – to be competitive with existing LM P2 cars but with half the power output and using half the fuel. Its unusual form – extremely narrow and low – meant it had a much lower power requirement and could therefore use a much smaller...
In 2010 I wrote a RET-Monitor article on assembled or ‘split’ crankshafts. In it I mentioned some of the applications of this type of crankshaft assembly, and discussed some of the advantages and disadvantages. There was a brief mention of the use of welding in the assembly of such crankshafts, but no further explanation. Although somewhat late in doing so, I’d like to explain more about the reasons for welding. The 2010 article mentioned that welding is sometimes used to...