In the previous article on valves, I turned to the subject of reed valves and their use in the induction section of a two-stroke engine. In race series where two-stroke engines are still popular, reed valves are commonly used and, owing to their mechanical simplicity, are likely to remain so. They require no mechanical drive or other actuation, and depend only on pressure differentials to open and close.
There have been a number of uses of reed valves on Read more…
In the destructive world of NHRA Full Throttle Drag Racing Series Funny Car competition, few parts take more of a beating than valve springs. “What kills them is going up and down 8000 times a minute uncompressed, as close as we can get them,” says Jim Dunn, who runs his eponymous Funny Car race team from a small workshop in South Gate, California.
Dunn is pretty much of a throwback to the earlier days of straight-line competition, a man who prefers not to Read more…
Although attaining speeds up to and in excess of 100 mph on tarmac is not an arduous task, it is a rather more multi-faceted undertaking on water. One of the many considerations of high-speed marine applications is transmission and propeller design. There are a number of high-speed marine formulae that use various propulsion systems, including water-jet drives, super-cavitating and surface-piercing propeller drives.
The Oulton Broads and surrounding areas, in Suffolk,
In a recent RET-Monitor article on the subject of surface treatments for magnesium, mention was made of plasma electrolytic oxidation treatments. One such treatment that has found application in motorsport is Keronite, and while it is popularly used for surface treatment of magnesium components, the process can also be used with the other popular light alloy materials, namely aluminium and titanium.
I discussed the process with Dr James Curran, principal materials engineer at Keronite. Much of the initial engine Read more…
I know it’s hard to credit it, but before 1937 the ‘O’ ring didn’t exist. Patented in that year by Danish immigrant to the US, Neils Christensen, an ‘O’ ring, while eminently simple in concept, is in practice a very powerful sealing mechanism. No wonder they can be found in any number of critical applications inside most purpose-designed race engines. At the base of the cylinder liner, around the body of the fuel injector and at the top deck of the cylinder block sealing oil and coolant as it passes into the cylinder head - these are all critical areas where a Read more…
It may sound obvious, but to assemble a piston ring into its grooves in a traditional two- or three-ring piston will require the ring to be split at some stage during manufacture. Placed on some form of mandrel and heat treated thereafter to an out-of-round set, once placed onto the piston and assembled in the cylinder, the theory is that it should exert a more or less constant pressure all the way around the bore.
Simple and yet highly effective, there are however two Read more…
After having written in my previous article about process control issues, something occurred to me about the differences between engine applications. In general, RET-Monitor and Race Engine Technology magazine put an emphasis on high-performance engines. This often means also high-revving engines, due to the simple assumption that the easiest way to make power is make use of high rpms.
What came to mind is what this statement means in Read more…
Jim Dunn is a throwback in the modern world of NHRA Full Throttle Drag Racing. Operating his professional Funny Car team on a budget that would embarrass amateurs, and doing so without computers, Dunn manages to procure sponsorship from good firms like dog food manufacturer Canidae and keep driver Paul Lee qualified in large Flopper fields.
Dunn has been using Bill Miller Engineering (BME) pistons and con rods for at least 15 years, he says. “Well, I tried Read more…
In any dry-sump engine application the task of getting the oil out of the sump is often much harder than putting it in. This is because oil tends to flow better at the 3-4 bar pressure at the outlet of a pump than it does at the 0-0.7 bar depression of the oil-air mixture at the inlet. For this reason you will often see at least two scavenge stages emanating from the sump of a dry-sump engine and possibly another from each of any cylinder heads.
For a vee engine, therefore, we are likely to see at least Read more…
It is surprising how often people get mixed up between the prefixes ‘hypo’ and ‘hyper’. While ‘hypo’ refers to a situation that is less than normal, ‘hyper’ relates to exactly the opposite. As an example of such confusion I have a neighbour who speaks with a highly refined tone and continually refers to her ‘hyperchondriac’ husband, when I am sure she means ‘hypochondriac.’
So too are the differences between hypoeutectic alloys of aluminium and silicon and their hypereutectic alloys.
