More than 15 years ago, a young David Coulthard said he was "very excited" about a new development at Williams, going on to say that "machine is working better than man". The reason for his enthusiasm was that he had just tested Williams' revolutionary continuously variable transmission (CVT) system. This was in 1993, and the system so worried other competitors and the FIA that it was banned before it could be raced. There is video on the internet of the car being...
In our May issue, we spoke about the challenges of pushrod fitment issues and how to find the proper avenues for combating strength and lightness problems. Beyond fitment though, there are the closely linked issues of pushrod adjustment and the inevitable challenge of cost. Fine adjustment will always be needed in the valvetrain to allow for manufacturing and assembly tolerances of such a long chain of interacting components. Typically for pushrods, much more adjustment than that is...
For Morgan Lucas Racing's John Stewart, tuner for second-year NHRA Top Fuel driver Shawn Langdon, the change from titanium valve springs to steel units was due to the cost. "A set of titanium springs is about $1500, and we can get a set of steel springs for about $500. They seem to last just as long," Stewart says. "With the economy and money as tight as it is, we're trying to save as much as we can. The cost difference of $1000 is a big deal. You can buy a lot of sets...
In racing valvetrains, there is always an imperative to reduce reciprocating mass, as it allows the valvetrain engineer to be more aggressive with his cam profiles in an attempt to improve the valve lift curve, by increasing lift, increasing the area under the curve and so on. This will generally require greater valve acceleration or deceleration.If we are constrained to using the existing valve design, we may be able to cope with increased forces and stresses due to increased...
Previous articles have mentioned a few materials that are used for pistons, and the subject was also covered in a recent Race Engine Technology article on pistons. But there is one material that has been hailed by one piston design expert I spoke to as being ideal here - aluminium-beryllium. Blessed with a combination of desirable properties that may be present individually in other materials, it would almost certainly have been the material of choice now, had it not been banned by the...