Of all the components in a typical oil system, the function and hence usefulness of the oil filter in a modern racing engine must surely be one for review. Designed to separate the larger particles which somehow accumulate in the oil and prevent them from returning back into the engine, there is little doubt that in most roadgoing vehicles some kind of filter may be necessary. In a racing engine however, which is put together under the cleanest of conditions and then assembled into the chassis in workshops where quite frankly, I Read more…

Rather like the blood circulating around our bodies, the lubricating oil in an engine is fairly critical to its well being. For most of the time we don’t give it a second thought but it is only when things go wrong that people start paying attention. And for most of these the first thing they will notice is a reduction in oil pressure.

Low or no oil pressure at all is a common enough problem and while the obvious (to some) culprit might be the oil pump, in 999 cases out of 1000 this does not turn out to be the case. Their logic is simple. No oil Read more…

Apart from the accidental ingress of debris, the greatest danger to any design of oil pump, particularly one of the gear tooth design, is that of cavitation. Commonly found in centrifugal pumps also, the presence of this phenomenon and the resulting surface erosion is often confusing to the uninformed.

A complex process having one of many causes, for an adequate explanation we need to understand and explore some of the more basic principles of fluid mechanics. In particular if we consider the case of steady flow Read more…

It is surely an obvious statement of fact that what goes in, will eventually come out again – somewhere! Filling the bath with water and then watching it drain away again afterwards is an example. The joy of watching the bank balance rise at the end of the month and then tearfully watching it ebb away again in the weeks following, is another. But unlike these examples, which would appear to happen without any effort at all, the task of extracting the oil out of an engine comes at a price. And that price on a race engine, is the highest of all – power! So while we are consuming power to pump the oil into the engine Read more…

The science of engine development is one of incremental steps; small but measurable increases in power over a period of time. Improvements in port flow, increasing the engine rev limit or changes in intake or exhaust system sizes will, no doubt, help. But while that is undoubtedly the high profile, glamorous part of development, as far as engine performance goes, it is only half the story. The other, perhaps less glamorous part is that of minimising the parasitic losses; the friction in all the sliding components and the power to drive all the auxiliary drive systems - which includes of course, the oil pump. Read more…

Last month we looked very briefly at gear pumps, in particular, external gear pumps when two gears sit side-by-side. A particular derivation of the gear pump however, sometimes referred to as an internal gear pump or internal-external gear pump is when one external gear fits inside a rotor consisting of an internal gear. With the centres of each gear offset from one another and a differing number of teeth on each of the gears, rather like its external counterpart, the resulting cavities can be made to pump fluids. A specialised form of this design which, rather than using an involute tooth profile Read more…

Having established that a positive displacement pump is the only practical way of supplying lubrication to our engine, the question remains as to which of these many types is most suited. And to understand this it is necessary to examine the engine’s demands on the oil.

In any high performance unit the oil has two primary functions: to lubricate (obviously) and to cool. For more mundane applications we can also include things like ‘to protect against corrosion’ or ‘ to minimise the build up in deposits’ but since I am assuming that the oil Read more…

Few of us give our oil pump a second’s thought. So long as that big red light on the dashboard keeps going out at the required time and doesn’t flash too much when the engine is hot and idling, then all would seem to be well. But the poor old engine designer, when setting out at the initial design stage, has much to think about. To begin with, he realises his engine will need lubricating oil flow to the main and big end bearing assemblies. Notice the word flow and not pressure. The oil pressure is required mainly to overcome the centrifugal action of the oil in the crankshaft feeding the big-end bearings.

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The oil pump in any engine has been likened to the human heart. At the core of operations it provides the essential life-giving fluid to all the other components and surfaces in the system. And while there are many other similarities, unlike the human heart, the oil pump seems to be accepted as some form of necessity but given very little attention thereafter.

In part I guess this attitude stems from our road-going transport habits. Buried away deep inside the power unit and out of sight, the only time we might ever think

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NASCAR is moving toward parts commonality in nearly every facet of its competition. Currently, discussions are underway to produce an oil pump system that is common to all three of NASCAR’s national series: Sprint Cup, Nationwide Series and Camping World Truck Series.

While this change likely will not occur until the 2010 season begins, NASCAR is considering announcing a rules change midway through the current campaign. Read more…