A motorcycle engine, indeed any engine running at over 10,000 rpm, presents a particularly difficult challenge to the surface of its cylinder bore. The amount of heat flux and the limited time to dissipate it through the cylinder wall and into the coolant, will inevitably lead to high running temperatures and all of its associated problems. Although lightweight aluminium cylinders have been used to assist with the heat transfer, to minimise durability issues, thin steel liners have often...
The humble rotating shaft seal may be an afterthought for many a designer but its history is certainly never lacking in acronyms! Early lip seals were made using a nitrile rubber. Now referred to, as NBR the application was limited to working temperatures of no more than 90-100 degree C immediately under the lip at the rubbing surface. Changes in seal designs at this stage to use much narrower contact points not only improved its performance, but also reduced the amount of heat generated...
For those of you following the ‘Focus’ articles in Race Engine Technology magazine, it is clear that recent changes and improvements in manufacturing technology have improved the products being examined, and this is undoubtedly true for most machined parts, and also for parts produced by casting and forging too. Clearly the CNC revolution has not left the world of fabrication untouched with many operations controlled by computer being more accurate than the average man could ever...
In the recent Race Engine Technology magazine article on the subject of fasteners, Wayne Ward touched on the subject of locking nuts and locking thread inserts. There are a great many applications where the loss of a fastener is not critical to the operation of the system as a whole; indeed it is common to build in a certain level of redundancy into a bolted or riveted joint for loss or failure of fasteners and the accompanying loss of pre-load. Again, even in this situation, the physical...
I think it was the great Liverpool F. C. manager Bill Shankly who once professed that football wasn’t a matter of life and death – it was more important than that. But strangely enough, the words – ‘football’, ‘life’, and ‘oils’ have all come together recently making substantial improvements to gearbox durability especially those with sequential changes.Transmission oils are similar, in many ways, to your typical engine crankcase product;...