There is a vast array of metallic materials of all kinds whose mechanical properties are improved by heat treatment. Steels are commonly raised to high temperatures, quenched and subsequently tempered by raising the temperature to a carefully controlled level and maintained there for a known amount of time; aluminium and titanium alloys are often solution-treated by heating to a given temperature before quenching and age-hardening by heating. In the case of most steels after quenching, the...
The chassis dynamometer may be a convenient way of loading an engine, but to undertake any serious engine development requires a dynamometer attached directly to the output shaft of the engine. While there are various types of engine dynamometer on the market, perhaps the simplest and least costly is that of the water brake. Classed as a hydraulic machine, while some types of hydraulic dynamometer may use a pump to circulate oil, the water brake relies totally on a different fluid - water....
In order to reduce stress and improve mechanical performance for any highly loaded powertrain component, surface finish is of the utmost performance; a superior surface improves fatigue resistance by removing potential stress raisers and the possibility of crack propagation. For geartrain components this is especially important, requiring high surface hardness to maintain impact strength and resist bending loads on the gear teeth, even though most of the gear material itself must exhibit...
In the RET magazine Focus article on pushrod valvetrains (issue 45, March/April 2010), we looked at the effect of flat tappets in limiting the lift velocity of a direct-acting cam on a lifter. The limitation is exactly the same as that in direct-acting overhead camshaft engines. Textbooks on the subject tell us that the distance of the cam-to-lifter contact from the axis of a flat tappet is proportional to the lift velocity of the cam profile. The exact relationship is shown in...
How much valve spring does an engine tuner need to propel 8000 hp down a 1000 ft dragstrip? Is it best to use titanium, or is steel sufficient? And are two springs best, or should there be three? For Bob Vandergriff Jr's C&J Energy Services National Hot Rod Association Top Fuel dragster, this year competing full-time in the Full Throttle Drag Racing Series of 22 events, the choices are predicated on a change to the set-up configuration for the 2011 season. Working to gain reliability...