Even as a boy I was continually mystified, and occasionally perplexed, by the operation of the carburettor. The myriad of main jets, air correction jets and emulsion tubes and the science on the fixed jet DCOE was a veritable minefield for the inexperienced, but once mastered, the satisfaction of getting an engine to start let alone run sweetly on the road or track, was reward in itself. The arrival of electronic fuel injection with its altogether totally different approach was greeted...
In the inexorable search for reduced weight, the various alloys of aluminium are most commonly used for high performance gasoline engines. Where peak firing loads are higher, for example as in the case of a modern direct injected diesel engine, this may need to be some form of S.G. (spheroidal graphite) iron. With its excellent flow properties in the molten state, sections can be cast much thinner than other cast irons and thus the disadvantage of a density nearer 7 gm/cm3 can, to a...
The surface condition of the cylinder bore has occupied the minds of motorists, engineers and enthusiasts for many years. Often expressed in terms of oil consumption – miles per litre or miles per quart depending upon which side of the Atlantic you reside – provided consumption isn’t excessive, all is generally thought to be fine. In a racing engine however, where cost of ownership is, let’s face it, more or less irrelevant, the real issue here is one of friction. In...
While it might be the aim of many engine designers to minimise the chance of any oil leakage by dispensing with the humble rotating shaft seal, it may not always be possible or even desirable. At any point where there is a mechanical take-off in the form of a rotating shaft, an oil seal will need to be present and while race engine designers try to minimise these occurrences, for the rest of us wishing to improve existing OE equipment or re-engineer old engines, that option simply does not...
Last month we looked at the problem of how to contain excessive heat given off by hot exhausts. The problems this heat causes affect not only the engine, but also other systems, particularly electronics. In addition to wrapping or coating the exhausts, we looked at the concept of bagging or blanketing. Heat shields were mentioned and in Formula One at least these are commonplace, being lightweight and effective in shielding the engine from radiative heat transfer. The problem with wrapping...