In a recent article in the crankshaft section of the website, I discussed very briefly the methods by which heavy metal counterweighting can be added to crankshafts. Heavy metal is the common term, but a more technically correct description would be dense metal, and these are generally tungsten alloys. The picture which accompanied the aforementioned article showed additional counterweighting mass in the form of cylinders or slugs of tungsten pressed into place in each counterweight. There...
KINETIC ENERGY RECOVERY SYSTEM (KERS) EXPLAINED KERS is a collection of parts which takes some of the kinetic energy of a vehicle under deceleration, stores this energy and then releases this stored energy back into the drive train of the vehicle, providing a power boost to that vehicle. For the driver, it is like having two power sources at his disposal, one of the power sources is the engine while the other is the stored kinetic energy. What is kinetic energy (KE) Kinetic energy is the...
FATIGUE AND WEAR IN A JOURNAL BEARING (during start-up and boundary lubrication)When two bodies are pressed together contact stresses occur. The results of the work done in this area are due to Hertz and are referred to as Hertzian stresses. Two special cases of hertzian stresses are: contacting spheres and contacting cylinders. An example of contacting spheres would be a single row ball bearing, with a single ball contacting the inner surface of the inner or outer race. An example of...
In a good camshaft design the cam profile is but one half of the story. Lifting the valve off its seat and then opening fully before closing it again and dropping it gently back onto its seat requires a lot of careful mathematics and, executed well, should give the maximum valve area opening period for the minimum of forces involved. But just as much as efficient inlet and exhaust cam profiles are critical to any high performance engine, the timing of their opening and closing in relation...
The use of polymer coatings in racing engines has been widespread for many years, but is to some extent being displaced by the newer generation of coatings such as titanium nitride, chromium nitride and DLC as examples. In a lot of circumstances the newer coatings are an improvement, but the coatings rely on the fact that there will be no significant deformation of the coated surface, otherwise the thin coating, which itself is brittle in comparison to the underlying substrate, can craze...