Archive for the ‘dynamometers’ Category

Humidity - forget it?

Wednesday, November 10th, 2010

dynamometersIn my younger days, when fuel injection was but a luxury and the roads were less crowded, the journey to work was always so much more enjoyable in the foggy early morning light than at any other time. The engine in my transport - a high-compression ‘A’ series unit, tuned ever so close to (and sometimes beyond!) combustion ‘knock’ - would run totally free of detonation and be a joy to drive around the twisting country roads where I lived.

As a development engineer I put this down to the water Read more…

The flywheel effect

Tuesday, September 28th, 2010

dynamometersNow that kinetic energy recovery systems (KERS) are back on the agenda in Formula One and Le Mans prototypes, it’s a reminder that a flywheel is not only a convenient place to attach the clutch, it can also be used to store energy. As well as electric motor/generator systems, several other KERS units have incorporated flywheels running in a vacuum.

When the car slows down, the energy otherwise wasted as heat during braking is stored in the flywheel and released back into the driveline at the next opportunity. Read more…

The control freak

Tuesday, August 17th, 2010

dynamometersI’m sure we’ve all been accused of it at some time - the compulsive desire to have things just the way we want them, with little or no compromise. Perfection is the goal, anything else is a poor second best and, except in the case of pure genius perhaps, it is often considered a major flaw in one’s character. But in the world of engine dynamometers, control is everything.

Many of you will no doubt be familiar with the large and unmistakable throttle lever alongside the console of an older engine test bed. Linked directly to the engine throttle via an equally unambiguous control cable or metal rod, throttle control was left entirely to the tester, and should anything become amiss or the engine detonate for so much as a split-second, the throttle would be wrenched away from fully open or rammed shut as an instinctive reaction. Read more…

Corrective action

Friday, July 2nd, 2010

dynamometersThe definition of an engine is apparently “a machine that converts power into motion”. This may be true in its widest sense but when it comes to rotary outputs, I like things to be more precise. Far be it from me to contradict the Oxford English Dictionary, but in its basest form surely an engine is “a machine that converts torque into motion”?

I know I’m being slightly pedantic, but engines - at least the ones we are more familiar with - are designed to produce torque at a particular

Read more…

‘Optimising’ the gasoline engine?

Thursday, May 13th, 2010

dynamometersPerhaps the most common word used today in engineering is ‘optimise.’ Now, my memory may be a little bit selective, but until about 20 years ago the word was rarely used. But I have a theory. In the past, engineers were probably far too busy concentrating on getting things to work in the first place than working to their optimum, or perhaps it’s because today’s engineering ‘tools’ - and by that I mean software - are far more discriminating, allowing finer degrees of control. Or perhaps it’s a combination of both. Even so, when it comes to Read more…

Emission Testing in Motorsport

Tuesday, March 30th, 2010

dynamometersAmid all the hype over the past few years of Global Warming or as it has been re-branded now, Climate Change, it won’t surprise anyone that motorsport has come in for its own fair share of criticism. Viewed by some as a waste of resources, the sport is now fighting back and where once the word ‘power’ was king, ‘efficiency’ now replaces it. But from a motorsport perspective, ‘efficiency’ can mean many different things but in the final analysis and in today’s world it all comes down to one thing - fuel consumption or as the politicians would now Read more…

The DPX

Tuesday, February 16th, 2010

dynamometersThe most common type of engine dynamometer today used by engine builders the world over, must be the eddy current machine. But few will ever forget, of those who ever used them, the DPX water brake. Made by Froude in Worcester, England since shortly after the turn of the (20th) century, and once to be found gracing some out-of-the-way engine test facility at University, to many this would be their introduction to the subtle art of engine testing. Classed as a fluid friction device, resistance to the torque of the engine is offered by a combination of shaft bearing friction, Read more…

The Chassis Dyno

Thursday, January 21st, 2010

dynamometersBelieve it or not measuring the precise output from a reciprocating engine has always been a controversial and sometimes, difficult task. Even in the confines of the engine test cell, day-to day repeatability can often be onerous not to say expensive and so it is easy to understand why many competitors may prefer to test their engine while it remains in the vehicle - on a chassis dynamometer.

Engine dynamometers are generally the province of serious tuners and the OE engine business. Attaching the Read more…

Reliability testing in Formula One

Saturday, December 19th, 2009

dynamometersWith the ban on in-season testing, one of the greatest increase in uses of any other testing equipment is that of the power train transient dynamometer. Costing millions of pounds to buy and even more to run, these are used to simulate precisely the events experienced by the engine and transmission as if it were installed in a vehicle circulating around the track. Controlling not only the engine speed and load but just about every other parameter you can think of – air temperature and humidity, oil temperature, fuel temperature, not to mention the shock loading directly as a result of changing gears, the dynamometer system also tries to simulate Read more…

Addressing the Envelope

Sunday, November 15th, 2009

dynamometersToday is the first of many strikes, or so we are told. The continuing dispute between management and unions in the Post Office has resulted in this, the first of a number of planned one-day stoppages across the UK on which the mere thought of reaching for an envelope and putting pen to paper is but the last thing on my mind. As engineers however, ‘addressing the envelope’ has an altogether different meaning. Other than a flat paper container with a sealable flap, to engineers an envelope is a containing structure or a boundary beyond which we stray only at our peril. Read more…