There are several types of materials which are currently used for con rods – some for reasons of manufacturing, some for reasons of quality, but most have been specifically chosen owing to their particular combination of mechanical properties. This month we shall begin to look at con rod materials and, in those cases where they are chosen for reasons of properties alone, what makes each suitable for the particular application. In terms of circuit racing, the main types of materials...
In the previous article, we looked at the first stages of heat-treatment in the manufacture of crankshafts. Certainly in Formula One, the most popular heat treatment that will be mentioned will be nitriding. Nitriding, as most of you will know, is a surface treatment which, if specified correctly, should have no effect on the bulk of the material, often referred to as the core. When we specify the material for the crankshaft, we need to be careful not only to specify the composition of the...
This may mark me as some kind of ancient relic but at one time the height of engine sophistication was the part-throttle weakening device. Designed to improve fuel economy by running the engine lean when the carburettor throttle plate was away from wide-open throttle, this ingenious instrument was perhaps the pinnacle of engine management technology in its time. Injection systems were around but were predominantly mechanical in nature, very temperamental and gave very poor air fuel ratio...
Many years ago, as a young and somewhat naive apprentice, I was told by my training supervisor to go to the engineering stores and ask for ‘a long wait.’ Thinking that this was some form of specialised turning tool, I dutifully did as requested only to be told after 10 minutes at the counter “You’ve had your long wait, now clear off!” Engineers and former apprentices of a certain age might recognise my continuing embarrassment. So when the idea of the...
Historically, the relatively soft grey cast iron cylinder liner with its inclusions of graphite, correctly prepared, has made an excellent material when running against much harder chromium plated rings. However, the differences in thermal expansion between the liner and that of the aluminium alloy piston make it necessary to introduce a greater than desirable radial clearance to prevent piston scuffing and eventual seizure. As the specific performance increases along with larger diameter...