Time was when the application of the white of a single egg - be that free range or battery, it didn’t seem to matter which - was enough to cure that annoying little water leak. Dropped into the top of the radiator, the action of the engine being progressively warmed was sufficient to denature the protein in the albumin and form a thick white mass, sealing the leak or at least sealing it enough to get you home. But with modern critically cooled engines, narrow cooling passageways using minimal amounts of transfer fluid, such practices are best consigned to the memories of old men and heroic tales from the past. Read more…

If a shaft spinning at 20,000 rpm can pose a sealing problem then what about one doing 120,000 rpm or even, dare I say it, 240,000 rpm? A simple enough question, you might say, but before answering it we need to understand the application and the desired effectiveness of the seal required.

A crankshaft oil seal for instance needs to be 100% reliable under all conditions. This is because in the mind of the customer, it takes but a single drop of oil to constitute a failure. In the case of a Read more…

If you thought it was only race engine manufacturers who are paranoid about friction at the crankshaft seal, think again. The inexorable push towards ever lower CO2 emissions - better fuel economy to you and me - is making many an original equipment (OE) engine component supplier look much more closely at its products.

Chief among these is Federal-Mogul, which has just introduced a ‘new approach’ to lip seal technology, Read more…

The interaction between the elastomer seals in an engine and its lubricant is an ongoing battle. Referred to simply as ‘compatibility issues’ by the specialists, the damage inflicted on the seal by the lubricant can manifest itself in two ways. The first of these is considered to be the direct chemical attack on the elastomer matrix resulting in its loss of performance (as a seal) while the second is the combined effect of this and the dynamic stresses applied. While the latter can be addressed by thorough dynamic testing, much of Read more…

As many might know to your cost, the cylinder head gasket is high up among those engine components to suffer the greatest stress. Often a weak point in some of the best engine designs, its unenviable task is to provide a robust seal between the cylinder head and corresponding crankcase for the combustion gases, oils and coolant, both between each other and the outside atmosphere. If that were not difficult enough, the component also acts in distributing the dynamic loads between the head and block and as a consequence, has a considerable influence on the forces Read more…

The humble rotating shaft seal may be an afterthought for many a designer but its history is certainly never lacking in acronyms!

Early lip seals were made using a nitrile rubber. Now referred to, as NBR the application was limited to working temperatures of no more than 90-100 degree C immediately under the lip at the rubbing surface. Changes in seal designs at this stage to use much narrower contact points not only improved its performance, but also reduced the amount of heat generated in the first

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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 exist. However armed with a knowledge of the design parameters around which these seals perform best, there Read more…

One of the world’s leading race engine manufacturers has revealed their design philosophy regarding seals and gaskets to RET Monitor this month.

Dave Salisbury, Chief Design Engineer at Engine Developments Ltd (EDL), told RET Monitor, “It’s a simple philosophy really… we just work hard to eliminate seals and gaskets wherever we can.”

Whilst that sounds straight forward and much like common sense it is actually something which is very hard to Read more…

In this and future issues we will look at one of the most critical seals in a race engine, the seal between the top of the cylinder bore and the cylinder head.

There are of course many ways of achieving this seal, but perhaps the first question we should ask ourselves is whether or not we need to have a joint which needs sealing in the first place.

Race Engine Technology magazine is soon to feature Read more…

In the first RET Monitor Seals and Gaskets article, we started to examine the research which Trelleborg Sealing Solutions, a leading multi-national manufacturer of gaskets and seals, has published into the interaction of sealing compounds with biofuels. This research will cause fuel system designers to rethink material selection for sealing gaskets and O-rings.

In that article we focused on water contamination of bio-diesel, something which is to an extent, almost inevitable. Water contamination has a significant detrimental effect Read more…