Have any of the Stalker or Discovery guys tried using Denatured Alcohol or E85 and oil as fuel? Seems these engines could work fine particularly with the denatured alcohol as it is 85% ethanol/15% menthol. The E85 is same but 15% gasoline. Let us know.

Best,   DennisT   

Brian,
This is interesting, it is very similar to denatured alcohol here in the states. There is an additive that the diesel guys use as an ignition improver call AMSOL Cetane Improver, its main component is a chemical call 2-Ethylhexyl nitrate. 2-Ethy has an auto ignition temp of 266F (130C). I think a 1/2% of this (or maybe just 1% simple lighter fluid) would solve the start issue and should also improve the revs. Basically, the 2-Ethy will advance the ignition timing of the fuel and get is burning a bit quicker. What oil did you use?

It seems that the E85 could work well also since the 15% gasoline will act as the ignitor, might need lower compression than the No Nitro engines.

Thanks for the input.    DennisT

Brian,
That's good information. If we could get solid engine runs with either the DNA or E85 it would reduce our fuel cost considerably. Seems we could use Klotz/castor or maybe one of the heavy 2 cycle oils (mixed per our normal 22 -27% amount, not the 50:1 they use). Second, would allow simpler paint choices as you would not need "death paint" top coat.

As to ethanol vs methanol, ethanol has an auto ignition temperature of 689F, and a heat value of 12769 btu/lb: methanol is 878F AI and 9888 btu/lb heat value. Methanol's advantage is it has a bit wider fuel/air range up to 33:1 vs 19:1 for ethanol. Methanol also has a 12 deg higher flame temperature at 1549F. But they are very close and as you said maybe a little higher compression or ignitor to kick it off (a drop or two of lighter fliud) would help the starting.
 
In stunt we don't change things too fast. Most people don't have the time to test and adjust to make new things work. Whatever the top guys do (and even they don't have time to change much) is pretty much what we follow. Its good that you were able to do some testing, maybe it can be built on and help the hobby grow.

Best,   DennisT

Naptha ("white gas" or "Coleman lantern fuel" in the US) is a nice additive to methanol/castor fuel -- it extends the run a bit, but more importantly for this discussion, it seems to be an ignition promoter.  It may be interesting to try a jot of that (the guy who recommended it to me says no more than 2oz/gallon) and see if it helps ignition and needle range.

The idea is to get 0% nitro fuel. The Stacker and Discovery's run best on 0% nitro.  I think the denatured alcohol has the best shot and because the ethanol has a lower auto ignition temperature might work better with moderate compression (say 9.5:1 ish) as apposed to 12:1 for menthol. Might need a hot plug. Stalker 66 head for no nitro fuel, they seem to use a wider squish band to get the higher compression they use.

Best,  DennisT 

For running any kind of fuel with gasoline or stove fuel, you can use Walmart Super Tech either synthetic or standard 2 stroke oil I run my ignition engines on the standard two stroke oil, 3 to 1, or 25 percent oil. My OS 60 FS four stroke that I converted to points ignition, I run 16 to 1 stove fuel to Super Tech synthetic two stroke oil. I have run it for hours and the valves are just as clean as the last time I cleaned them before switching from fuel with castor to ignition.

In fact, the top of the piston is still clean. And no noticeable wear. The thing is, when you start running stove fuel or gasoline it only takes a little over half as much. Much harder to get the right amount in the tank for the run time.