Pascal
Senior Heliman
Location: Paris, France
| Hello,
Answering about the plug is not as easy at it looks, because the plug should match your fuel, and and the same apply to your carburator.
The documentation supplied with the 3DNT gives you the exact recommendation for your needles and the fuel. Just follow it.
If you do not follow the documentation and use another fuel than recommended, the first question is how much oil do you have in your fuel.
Because the Lotterle carburator is adjusted for a given % of synthetic oil. Nitro percentage is not relevent, except that if you have 30% nitro and 12% of oil, I doubt that your engine will run for a full tank.
Your carburator has a needle that is optimized for 12% of synthetic oil (actually to the fluidity of methanol mixed with 12% of MG synthetic oil). The idle needle works from closed to 80-90%+ of opening.
If you have a higher % of oil say 16% and you adjust the needle so that it is OK when hovering in idle1 (1400rpm), it will be too rich when idling and too lean in idle2 (1790rpm). Then you will say that this carb does not work...
I personnaly mix my own fuel with 12% of MicroMotul and no nitro. It runs great. I amost never adjust the needles, only for major temperature changes.
The needle can be changed to match a given % of oil, actually very easily since it is hold by a simple magnet (behind the idle screw). There are many models of needle so that you could use this carburator with any fuel provided you know its % of synthetic oil (no castor oil within fuel).
For more power, you can use 7 to 8%... some do in germany during contests. It is ok provided your engine is cooled properly, which is the case with this piece of art used as fan on the 3DNT. Check the airflow while idling...
Now about the plug, provided you use the recommended pipe tuned properly :
No nitro : Enya 5 or 4
No nitro to 10-12.5% : Enya 4
10-12.5% and above : Enya 3
Last point, ordering the right needle is a PAIN. Lotterle has a website but does not speak english.
http://rd-modelltechnik.de/ could sell you the right needle but you will have to call them. (He speaks english).
As I hope I explained properly, all these parameters interact with each other, change one and you have to find a new solution.
My best advise : Follow the documentation, ie in your case, use the right fuel.
If you read french, you could visit http://sites.estvideo.net/helicorch...urlotterle.htm.
Maybe Stephen could be of help and arrange for supplying these needles.
Pascal |
