The question of valve material selection has been discussed before in the RET-Monitor. Much of the motivation for a given selection is provided by the operating conditions in which the valve must operate. Some materials are not suited for very high temperature use while others are too dense to be used in conjunction with very extreme valve lift profiles. In previous articles, we have looked mainly at the different classes of Read more…
Archive for December, 2011
Choosing valve materials
Thursday, December 15th, 2011Solving the problem of valve spring breakage
Thursday, December 15th, 2011
Finding the right valve springs for an inline four-cylinder USAC National Midget engine that makes upwards of 365 hp at the wheels could be a difficult procedure. But, says Erik Milholland, manager of the racing division at Kentucky-based Stanton Racing, “In the last couple of years we’ve found some really good springs.”
Stanton Racing fields both Mopar and Toyota Midgets in USAC competition. The company took over the build and rebuild procedures for California-based Toyota Racing Read more…
Formula One gearboxes
Thursday, December 15th, 2011
Formula One transmissions are the most advanced in the racing world, with an unparallel combination of performance, weight and packaged size. A key part of the gearbox is the casing, as it forms not only a housing for the gearbox internals but also acts as an integral part of the car’s structure. Here I will look at some of the construction methods and materials used to create these casing. Read more…
Phosphating
Thursday, December 15th, 2011
The use of phosphate conversion surface treatments, usually referred to as ‘phosphating’, are common in industrial applications, often serving as an underlayer for further coating processes such as painting. However, they have a number of applications in race engines and transmissions where they are not combined with further coating processes. In these applications they are applied in order to improve lubrication or for corrosion resistance. In terms of lubrication, phosphate conversion Read more…
The lower liner seal
Thursday, December 15th, 2011
Of the many gaskets and seals in an engine, probably the most annoying and terrifying in equal measure, when it fails, is that at the mid or lower liner. On dry-liner engines this doesn’t exist of course, so the product developers can sleep soundly at night. But in wet-liner designs this seal can be the greatest source of nightmares, because when it fails the area is so inaccessible. As ever, it always boils down to issues such as manufacturing cost and trying to keep things simple. But simple doesn’t always mean reliable, and Read more…
Nitriding
Thursday, December 15th, 2011
Nitrogen is a colourless, tasteless, odourless, mainly diatomic gas that makes up about 78% of the air we breathe. Chemically it’s almost inert, and as well as being a critical part of human DNA it can also often be an essential part of the DNA make-up of a piston ring. For example, titanium nitride and chromium nitride are popular piston ring coatings. Applied to the bore-contacting outer surface of steel rings, such surfaces Read more…
Rocker stands
Thursday, December 15th, 2011
In the previous article on rocker stands, and as a general theme to the subject of pushrod valvetrains, the importance of stiffness was stressed. Also important though is that the mechanism is set up on the engine as intended when designed.
This means that the relationship between the tip of the valve, the roller tip and rocker pivot are as designed. Not only does a badly set-up mechanism deviate away from the designed valve lift profile, but the relationship of the Read more…
Midget pistons part of a longevity boost
Thursday, December 15th, 2011
Stanton Racing Engines in Nicholasville, Kentucky, is known for its USAC Midget and Sprint engines. While once predominantly a Mopar/Dodge house, three years ago the company began to build/rebuild Toyota USAC Midget engines, taking over the work from California-based Toyota Racing Development (TRD).
Erik Milholland manages Stanton’s racing division, and travels with the USAC circuit, handling any powertrain Read more…
Wet sumps
Thursday, December 15th, 2011
It is a fact that wet-sump oiling systems are rare in racing. Given the g-loadings that most racecars experience, controlling the oil level while ensuring a constant supply of lubricant is far easier with a dry-sump set-up. However, some series still require the use of a wet sump, notably those for touring cars running to the FIA S2000 regulations.
Running wet sumps has caused problems for many years, as one engineer from a notable engine manufacturer Read more…
Taking the heat
Thursday, December 15th, 2011
In any internal combustion engine, the design or configuration of the cylinder or its liner is of critical concern. Exposed to the full effect of combustion at its upper part, which falls as we go down the cylinder, the component has to be as light as possible yet still retain its mechanical robustness with minimal distortion. As bmep (brake mean effective pressure) and engine speeds increase, cooling therefore assumes a major importance. Read more…
