In a conventional multi-point port injected gasoline engine the fuel is introduced into the air stream in the form of a jet of liquid. Atomising into small droplets, these mix with the air, begin to vaporise and eventually get carried off past the intake valves and into the combustion chamber. In between, varying amounts of this fuel might condense on the wall, travel along it and eventually vaporise back into the air stream. However the presence of this fuel, often referred to as a ‘puddle’ can have a significant effect on Read more…

Can you imagine waking up one day and not remembering where you are? I’m only too certain that this may have happened to many of you after the recent festivities but the experience is probably something you would prefer to forget. Perhaps then you might spare a thought for the feelings of an engine upon being cranked into life. Waking from its enforced slumber the camshaft will tell it when to open and close the intake and exhaust valves but who tells it when to fire the charge and more importantly on which cycle?

In times past the ignition was triggered from a mechanical Read more…

The news that the Large Hadron Collider, near Geneva in Switzerland is back in commission, is to be greeted with relief by all who have a genuine interest in particle physics. Designed to answer fundamental questions about the Universe by accelerating beams of high energy particles creating proton-to-proton collisions, the results, it is hoped, should provide explanations to some of the most basic of laws surrounding the most elementary of objects in space and time. And from all this we might just gain a further understanding of our Universe and its beginning, starting with the Big Bang. Read more…

Even as a boy I was continually mystified, and occasionally perplexed, by the operation of the carburettor. The myriad of main jets, air correction jets and emulsion tubes and the science on the fixed jet DCOE was a veritable minefield for the inexperienced, but once mastered, the satisfaction of getting an engine to start let alone run sweetly on the road or track, was reward in itself. The arrival of electronic fuel injection with its altogether totally different approach was greeted with relief more than any other emotion, not least because it solved the perennial problem of under bonnet packaging of large carburettors. But although the fuel could be

Read more…

Don’t you just love modern day IT terminology? I mean it’s so graphic, so descriptive and often without even knowing the purpose of the feature or component, simply hearing the name gives you a pretty good idea. Thus for instance, we have floppy discs which were, at least initially – floppy, and hard discs that are well, – hard! Thus when we hear the term CAN Bus, without fully understanding what might be going on and ignoring the pre-fix, our imagination conjures up pictures of people in a bus travelled up and down a road. At each stage along the way, people get on and off and carry their shopping Read more…

For those of you who have ever grappled with the art of carburettor ‘tuning’, the invention of the fuel injector must have come as something of a huge relief. The selection of choke sizes, main jets, emulsion tubes and air correction jets was all a bit fraught at times but once mastered and coupled with accelerator jets and something called ‘progression’, would seem to have guaranteed a job for life. Or so we thought. While the theory was always well understood it was only when we were able to view high-speed video that our true skills, or rather lack of them, was realised. Instead of the fine mist we Read more…

This may mark me as some kind of ancient relic but at one time the height of engine sophistication was the part-throttle weakening device. Designed to improve fuel economy by running the engine lean when the carburettor throttle plate was away from wide-open throttle, this ingenious instrument was perhaps the pinnacle of engine management technology in its time. Injection systems were around but were predominantly mechanical in nature, very temperamental and gave very poor air fuel ratio control. Little wonder that when emission legislation was starting to gather momentum, the search Read more…

Do we need electronic engine management systems? Really need them?

Because controlling fuelling, ignition, even valve timing, duration and lift achievable through electronic control units doesn’t necessarily mean that is the best or even the right solution. That is a deliberately controversial statement but it is worth considering what lies behind it and what the alternatives and options are.

Read more…

The silicon chip has made the task of performance engine design incomparably easier. An effective revolution in engine design for both gasoline and diesel units was made possible by close control of fuel and ignition through what were and are rugged on-board computers.

For the first decades of engine development, the performance characteristics of the engine were set through the original design: valvetrains, carburation, ignition timing and their relationship to engine revs were the tools that were used to optimise engine performance.

Read more…

Although an activity that is supposed to ‘improve the breed,’ motorsport has usually lagged behind road cars on engine management technology. There was a time when factory electronic injection systems on production-based cars were junked in favour of carburettors during preparation for racing. Even now, most of the capabilities of modern systems including traction and stability control are expressly forbidden by most rulebooks.

To be fair, motor manufacturers have never had any interest in making it easy for individuals and small concerns to tinker with engine electronics. Read more…