This year, for the first time in many decades, we find ourselves without a two-stroke engine in the Grand Prix classes of motorcycle road racing. For lovers of diversity in engineering in general and engines in particular, the class of 2012 Grand Prix bikes are perhaps a disappointment. Having seen the two-stroke bikes regulated out of existence with the demise of the 500 cc and 250 cc World Championships, 250 cc four-stroke single-cylinder engines have come to replace the 125 cc...
In the previous article on the subject of fasteners, the most commonly used method for the controlled tightening of fasteners was discussed. There are a couple of well-known equations that link tightening torque to fastener tension, and the more reliable of these was discussed. However, there is a great deal of variation of tension for a given torque, even for fasteners of exactly the same design. In terms of the equation itself, differences in the coefficient of friction and the...
There are few issues likely to get owners of classic and vintage vehicles in the UK hot under the collar than changes to the composition of the fuels. Fifteen or maybe more years ago, the furore was all about lead. Added to petrol at 0.15 g/litre, not only did it supply cheap octane to the fuel by improving combustion by avoiding detonation but the tetraethyl lead compounds used also coated valve seats, reducing wear and helping to minimise valve seat recession. Complicated by the phasing...
At a time when turbochargers are increasingly being touted along with engine downsizing for future road vehicle business, spare a thought for the old-fashioned supercharger. Driven directly or indirectly off the crankshaft, the air delivery characteristics of a positive-displacement, Roots-type supercharger are generally much more aligned with those of the reciprocating internal combustion engine. Consisting of two internal rotors in the shape of lobes rotating together, and phased using...
In the highest echelons of motorsport every system on a car is optimised to the greatest possible extent. For example, the volume of lubricant carried is pared to the minimum in order to reduce overall vehicle weight and the packaging requirements of ancillaries such as oil tanks. These packaging requirements also mean that the shape and structure of oil tanks will not always be the dictated solely by the need for consistent oil supply. Extensive work is therefore undertaken to simulate...