When we specify or design components for a racing engine, quite often we are interested in the surface finish. It is an important aspect of the overall perceived quality of the component, and it can have a large influence on the performance of the part in question for a number of reasons, of which there are three main ones to consider, namely endurance, wear and friction.
In terms of endurance, we know from reading Race Engine Technology, other magazines, Read more…
In racing we rely much more on machined components than our counterparts in the arena of series production engine design - we need to make parts quickly, we need the flexibility to make swift design changes and we want to take advantage of the improved mechanical and fatigue properties that high quality wrought materials offer us compared to castings etc. Whilst we all want to save money, especially in these straitened times of financial recession, we have less financial constraints than companies who have to produce hundreds of thousands of the same Read more…
In a previous article on the subject of surface treatments, RET Monitor contributor Tom Sharp discussed various surface hardening methods for crankshafts, and the method of nitriding was expanded upon in a subsequent article on the subject of nitride hardening. Not only does nitriding of steels offer a more wear-resistant surface, but there are substantial benefits from the introduction of compressive residual stresses with regard to fatigue behaviour.
Literature is littered with accounts of similar benefits Read more…
The use of amplified light has a great many applications in industry and beyond. Many of us reading this will do so having had our sight improved by laser eye treatment. In terms of the use of lasers in engineering, perhaps the most widespread application is laser-cutting, allowing sheet metal to be cut into any shape from a simple dxf drawing file. Many engineering works specialising in sheet metal will offer laser cutting nowadays. In a similar way, lasers are often used for part-marking purposes, from part and serial numbers to barcodes etc. Read more…
Last month we looked into induction hardening of crankshafts and the inherent differences between that process and nitriding.
We saw that induction hardening carries significant potential benefits; the main one being that the crankshaft is only heated locally which means that distortion can be effectively managed.
There is also no maximum limit on case depth with Read more…
Race engine crankshafts are typically produced from steel billets and are gas nitrided to improve fatigue life and reduce wear.
However nitriding is not suitable for all crankshafts, as the author found recently whilst detailing a crankshaft from a 70-year old historic Grand Prix racing engine. The crankshaft in question ran with rolling element main and crankpin bearings, in which the actual rollers ran directly on the journal surfaces of the crankshaft. Read more…
Leading crankshaft manufacturer, Arrow Precision Ltd, of Hinckley, Leicestershire, have recently expanded their capabilities by installing a rigid polishing machine for use on main and crankpin journals.
Optimising journal surface finish and cylindricity is key to minimising wear and improving fatigue life. The rigid polishing system works via a precision manufactured shoe, or housing, which contacts the entire bearing journal surface to be polished. Abrasive tape is then fed into the housing and around the journal surface. The crankshaft Read more…
Most people in the high performance world recoil when they hear a reference to cavitation. Cavitation, the formation of vapour bubbles in a flowing liquid, is usually the prelude to component failure, particularly
with propellers, impellers, pumps, and all forms of hydraulic machinery. In some cases, even cylinder heads have been known to fail from this phenomenon. Cavitation occurs when the pressure of a liquid stream falls below its vapour pressure. As bubbles form and then collapse rapidly, intensely destructive shock waves can be produced
For years now, race component manufacturers have closely guarded their proprietary metal super finishing processes. Using increasingly finer grinding mediums to produce the desired surface finish whilst still complying with the precise geometric requirements of the component.
Grinding is the traditional final metal finishing operation performed on engineered metal-to-metal contact surfaces such as roller bearings and some gears.
Non-electrolytic passivation (often referred to as conversion coating) is one of the most common treatments for aluminum surfaces that need to be made corrosion resistant, while still remaining conductive electrically. Because of its ease of processing, it is one of the lowest cost anticorrosion preparations available.
Chromate conversions (‘Iridite’ and ‘Alodine’) have been the traditional passivation application for aluminum alloys, both wrought and cast. Read more…
