In previous articles we have looked at the various materials used for valves, and examined some of the relative merits of these materials. The ’super-alloy’ materials are particularly suited to high-temperature applications, having been developed initially with a view to use in gas-turbine engines. But they are relatively heavy.
Titanium is much more favourable in terms of component mass, and is widely used in motor racing. The material comes with problems though; titanium requires surface Read more…
Known as ‘The Professor’ for his meticulous preparation and dedication to technological upgrades to his National Hot Rod Association (NHRA) engines, Warren Johnson continues to move forward in his quest to tune the best possible GM DRCE3 Pro Stock engine. Johnson figures he’s been working with this particular set-up for the past five years, and cites valve spring life as one of the larger challenges he faces on the 23-race tour.
While most press coverage of motorsport tends to look at big-budget motor racing, there are interesting technical features on many of the lower-budget machines that pound around the circuits during the summer weekends. There are a number of race series where lightweight cars powered by motorcycle engines are popular and successful. In the UK, Radical in particular has made a very successful business out of building bike-engined sportscars, and its V8 car has an engine based on two motorcycle top ends. 
It cannot be lost on anyone reading the articles I have written that an understanding or at least appreciation of residual stresses in engine parts can lead to improved component life or to the development of lighter parts. The book by Almen and Black, “Residual Stress and Fatigue in Metals”, is worth reading, if you can get hold of a copy.
In the quest to make engines as oil-tight as possible, we often forget the effect of the humble valve stem seal. Tucked away inside the cylinder head well out of sight, this small, upturned cup of a device grips onto the top of the valve guide and seals against the valve stem, enabling the valve to open and close without letting comparatively large quantities of oil get sucked down the clearance between the stem and guide and into the combustion chamber. With such a small component - and let’s not forget there are generally four of them per cylinder these days - it is therefore very easy to 
The increase in demand for specialist designer beers has led to a steady business in the supply of stainless steel barrels - or so we are told. Forsaking the traditional wooden barrel, which in the spirits and wines business is often known to add a characteristic flavour to its contents, these containers are very much utilitarian devices for transporting the contents from the brewer to the consumer with the minimum effort.
When thinking of a topic about ‘pushrods’, one might think on the specifics of the pushrod as a component. Another is to think of the way valvetrain systems have developed over time, from the low in-block camshaft and pushrod-actuated side valve systems to the current four double-overhead camshaft systems, and everything in between.
When General Motors got out of the National Hot Rod Association’s (NHRA) Pro Stock division a couple of years ago, it left behind a multitude of competitors using two of its engines in competition. The DRCE3 engine, newer than the DRCE2, has been the mainstay block-and-cylinder head combination for Warren Johnson Enterprises for the past five years.
The advantages of a good dry-sump system over that of a good wet-sump design in a race engine can be broadly stated as those of installation and oil control. The low-line sump pan in the dry-sump installation enables a significantly lower crankshaft centre line and the ability to control the movement of the oil to avoid ’surge’ when accelerating, braking or cornering.
As engineers we all have a lot to learn, and no matter how long we have been in the business, I am sure there is no-one out there who will not claim to be learning still. Take this lesson from the history books for instance.
