In the search for increased performance, the common direction of engine development has been to increase engine speed incrementally. While this trend is somewhat on the wane - owing to various regulations such as absolute rpm limits as in Formula One, fuel capacity/flow limits or the NASCAR ‘gear rule’ - high engine speeds are a good way to raise performance, providing that efficiency can be maintained. Read more…

Yamaha is the only company running an I4 in the MotoGP series, a layout to which it has been loyal since the inception of the current four-stroke formula; all the other engines are now V4s. Having the cylinders in a vee, rather than in a line, allows the crankshaft to be shorter and stiffer, with fewer main bearings, and the engine to be narrower. This is, however, perhaps not such a great advantage. Read more…

The provisional rules for the 2014 Formula One World Championship engines are now available to view on the FIA website. The change from the current 18,000 rpm 2.4 litre V8s to the 2014 1.6 litre V6 turbocharged engines was not straightforward, and came after a considerable period during which the engine suppliers were working towards supplying four-cylinder engines for 2013. Read more…

The crankshaft lies at the heart of the fundamental mechanical system in the vast majority of race engines. Only rotary race engines don’t have what we might call a crankshaft, although other mechanisms exist and which have been tested to turn reciprocating motion into rotary motion. Conventional wisdom has it that our steel race crankshafts are nitrided, almost without exception. An earlier article by Tom Sharp (1), posted in 2009, pointed to the fact that induction hardening is used occasionally on race crankshafts, although it is more Read more…

The manufacture of crankshafts is not a straightforward matter; many pitfalls await the adventurous novice attempting to make his own crankshaft, and there are reasons why there are so few reputable race crankshaft manufacturers.

The general trend for trying to reduce engine friction means that modern design practice is often in the direction of reducing bearing diameters. This means greater care needs to be taken in manufacture, Read more…

There are some materials regulations in motor racing that don’t make sense, because they stifle development and outlaw materials which just make good sense. The ban by many race series on the use of magnesium is one example of this, given that it has always been an affordable material and is common in series production. I imagine that many of those who write such rules drive around in cars with engines using magnesium. Materials are often consigned to this fate when they are judged to be expensive and ‘exotic’.

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One of the functions of a crankshaft, besides playing its fundamental part in an engine’s basic mechanism, is to transfer oil, especially to the con rod big-end bearings. In some cases, where all main bearings are directly fed from the main oil gallery in the cylinder block, and where drillings can take oil directly from the main bearing to the crankpin, there is no requirement to seal any drillings. However, in a great many cases, there is a need to reliably seal oil drillings, and there are a number of methods of doing this. Read more…

The reasons why we might want to augment the moment caused by the counterweight by using a dense material are well understood and, in previous RET-Monitor articles, some of the methods by which we can add ‘heavy metal’ to crankshaft counterweights have been discussed. In this article I want to discuss the method that is generally held to be the most effective - adding tungsten. Happily, it can also prove to be one of the cheaper methods, especially when judged by the criterion of most additional moment per unit of expenditure.

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In the previous article on the subject of adding tungsten counterweighting to crankshafts, we looked at one of the more widely adopted methods where cylinders of tungsten alloy are pressed or shrunk into specifically machined bores in the counterweights. The conclusion that many crankshaft manufacturers and design engineers have come to is that this is a reasonably effective method of adding tungsten while affording generous safety factors against failure. It is also simple from a practical point of view. Read more…

In the article on crankshafts which will appear in Race Engine Technology (issue 50, November 2010) there is a brief discussion on the use of heavy metals for crankshaft counterweighting purposes. There are a number of reasons why it might be deemed desirable to use a high-density material for a crankshaft but, for a given level of counterweight moment, it will lead to a lower inertia crankshaft assembly.

The advantages of adding a high-density material to a Read more…