The definition of an engine is apparently "a machine that converts power into motion". This may be true in its widest sense but when it comes to rotary outputs, I like things to be more precise. Far be it from me to contradict the Oxford English Dictionary, but in its basest form surely an engine is "a machine that converts torque into motion"? I know I'm being slightly pedantic, but engines - at least the ones we are more familiar with - are designed to produce...
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...