I just read a very interesting article about engine efficiency and power in the November issue of Technology Review. Although the article is entitle “Why Not a 40-mpg SUV?” and is clearly about auto engines, much of what is described as readily available could be transferred to aviation piston engines. It makes a good read and implies that FADEC is just a baby step.
Of course the odds of such a technology transfer to aviation engines in any reasonable time-frame are about 0.
Interesting article. Not all of the innovations will translate to aircraft use though. We already have a continuously variable transmission (constant speed prop), and the benefit of electromechanical valve actuators would be less for applications where the engine runs mostly at a constant speed. Same for shutting the engine off at red lights 
That’s not to say that aircraft engines can’t be improved, but the technology that is ALREADY used in automotive engines would be a good step, and provide the biggest improvement. It’s astonishing that our engines still use fixed ignition timing!!
A result of another ferderal gov. agency working at optimal performance ( guess we’d settle for ANY performance).
When you irresponsibly piss away a few trillion dollars…well…somethings gotta give…
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It’s astonishing that our engines still use fixed ignition timing!!
Clyde, what do you mean by fixed ignition timing? No timing advance (which can be mechanical) or what?
Walt
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Clyde, what do you mean by fixed ignition timing? No timing advance (which can be mechanical) or what?
That’s it exactly. Apart from an “impulse coupling” which retards the ignition timing while starting, aircraft magnetos have a fixed advance angle for all engine operating speeds (to be fair, aircraft engines mainly operate in a fairly limited RPM range, but even so, one dwell angle does not fit all operating speeds.)
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one dwell angle does not fit all operating speeds
Not only operating speeds but mixtures. The combustion rate is highly dependent on mixture which we vary considerably in our engines. At the perfect stoichiometric ratio you have the fastest combustion, and so need the timing retarded to keep peak cylinder pressure at the best point of mechanical advantage. As the mixture goes either leaner or richer, combustion slows and earlier timing is optimum. The mismatch between timing and mixture is what leads to most cases of detonation.
-Curt
Fixed timing - fixed mixture <
Yes, with electronics management (Injection), is possible to change the setting of the two things above.
In car/motorcycles competion this start some year ago (15 apx).
Now this technology is available in standard car/motorcycles engines.
Since 3/4 years ago, new system are available (I mean you can purchase it!) in competition car/motorcycles, while until few year ago, this was available only on factory car/motorcycles: Now, is possible setting you engine (timing and mixture) not only in a fixed way, but in a different way range per range, just connecting you PC with dedicated software to the engine.
F.I: If you are in a track, you can set different timing and mixture gear x gear / corner track x corner track, so you can have best help from your engine, driving easier and faster.
You can understood that this can work very well also in an aviation engines.
Try to think that your engine will change timing and mixture altitude x altitude, kind of “air” x kind of air.
This mean that your engine will improve their performance, giving it to you at any moment during a fly, without you must to take care of it.
Best power, best performance, best fuel flow. Do you like it?
This basically is the FADEC system Lyc and Continental are working on.
Honestly, I do not understand why it took so long time to become available, because it is already developed, and that is available from many years no more only in expensive car, but also in a “Honda Civic”!.
I do not understand why it should cost the amount Continental is rumored will be! Just for to prepare ourself to spend more we would to spend.
Magneti Marelli, Bosh and many other company developing and producing this system from many years ago for car-industry.
System is working weel, fully reliable year after year and with only one system per engine (no double as for aviation engines)Lyc and Tex-Cont choiced to develop this system with their own new company. This will increase their costs (and the system costs), the time for to be ready, a lot.
Customer will pay.
The opposite luckily Cirrus did and doing.
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This basically is the FADEC system Lyc and Continental are working on.
Honestly, I do not understand why it took so long time to become available, because it is already developed, and that is available from many years no more only in expensive car, but also in a “Honda Civic”!.
Maurizo,
The systems developed for automobiles have very different objective than aviation systems. The prime motive for the automotive systems is minimizing emissions of NO&NO2.
FADEC still has many skeptics. There is a very good thread on the Lancair board right now on this subject.
-Curt
Curtis, sorry,
I don’t believe electronics cars system works only for lower emission. There are system who workcs for the emission. timing and check and provide to keep every cylinder with right qty of air/fuel it needs for better performances and lower emission.
This systems are been developed for increase performance in the competition and later also for reduce emission.