Rotax 2 stroke ignition control systems..

[ZULU1]

I thought I would share this for discussion, now most people on this forum fly Ratex 582/503 motors, there is a growing trend (or should I say desire) to change to 4 strokes both Ratex and also BMW , Jabiru, HKS, Toyota, Suzuki and other as yet untested types. Really great stuff. But its definitely in most pilots hangar talk. This is as a result of several factors, spares costs tbo, endurance, reliability, noise or whatever. Now a thread started recently and i did some homework with this, additional fuel tanks. Anyway I clocked something last week, I fly a HKS and it does about 5-6 litres an hour, no issue. Don't even think about extra tanks or the weight that is carried..

I had a meeting yesterday with the fellows at Adept Airmotive at Virginia, we supply them toys etc. and I always like to hear of the latest. (It seems as though test flight no 2 is this week incidentally). Anyway after a lengthy discussion with them, they did some experimental work initially with a two stroke that over 6,000 rpm they switched off the spark ignition. This was apparently not dieseling but some other issue. So I described the 582/503 ignition, fuel consumption and other areas that the design has. They are aware of this and showed a desire to build a 3 cylinder 130hp turbo diesel, (another issue). The synopsis is that the ignition and engine management is really old tech, obviously the magneto coils and system is not capable of an advance setup and as they clearly understand that the set up should be mapped for altitude etc. But obviously the carbs must be retained. So they have agreed to investigate, eish they know more than us, the technology exits in Spain for mods to two stroke 125cc bikes and hopefully they will source something. Now as they stated the fuel burn will definitely drop, they can map other good things and it wont cost a arm and a leg...watch this space as it will probably work out cheaper than the replacement bits for the original...
But a 10 % improvement in fuel burn means 10 % more range etc....really this must be the way forward for existing motors out there.

see this for a start http://www.crd-international.com/ECU-En ... &langue=Ww

Zulu1

[MADDOG]

Hi Paul

Way back when I raced Rotax 2 strokes the mapped ignition modules where notoriusly unreliable. The power gain was slight, and once you knew what ignition map worked for your engine, there was no advantage in having changeable maps.
I personally think the simple magneto system is by far the most reliable and therefore most suitable for my aircraft.
The cost of replacement parts from the agent is another matter entirely, as is the poor quality of manufacturing (Vibration causing stator plate to rattle loose)

My 10c worth.

[John Boucher]

They are aware of this and showed a desire to build a 3 cylinder 130hp turbo diesel

Now that I like... especially if it is lighter than a 912 or Jab 6!

Imagine 90 litres @ say 10l/h...... all of a sudden one has a 1000km range with some serious HP up front!

Will have to install a "pee-pee" facility in the Cheetah