Gerald,
For the test you son ran did you use a petrol designed glow plug or regular plug? What oil did he use that would blend with the other fuels? Could try one other blend of petrol/kero/oil (maybe add a bit of the 10% for starting). One thing that would be interesting is to do a blend of the petrol and the 10% to see where you can get a bit more power but still save some cost. One thing to remember as you start using less fuel you are also getting less oil in the engine and may need to increase the oil % to prevent excess wear. 

Best,   DennisT

. A special fuel, a mixture of benzol, methanol and acetone with TCP anti-detonation additive, was used.

https://www.thisdayinaviation.com/tag/schneider-cup-race/

might pay to look up TOXIC , Carcinogenic , six toes , warts , cardiac arrest , deafness etc . 

http://clamf.aerosports.net.au/?page_id=2286

Classic B Team Race Fuels

Development of a ‘green’ Classic B racing fuel

Gas glow seems to yield varying results. Compression ratio must be optimized. Carb as well. Not many are adventurous enough to play with heads to make gas glow work. A few have tried glowplugs in the small Evolution gas offerings.

NV Engines has their GX-40 running gas which was briefly popular, but had an unusual requirement to run castor oil. It uses standard turbo plugs (hot). Rods were a weak point, iirc.

I had intentions of making heads for E85 and gas, but never got around to it. I tried the G5 plug with an FS-120S. It ran OK, but didn't make full power without plug heat. I haven't gotten around to increasing compression ratio.

     Loss of power should not be surprising - the early experiments with what we now call "glow fuel" were not trying to run without an ignition system, they were looking for more power by using "hot" fuel, that is, nitromethane (and in some cases, ether). It just also happened that it ran so much hotter that the spark plug glowed red enough to keep it going with no ignition.   So going back to using gasoline/E10/E85 would be expected to cause a loss of power over conventional fuel AND you have to carry an ignition and batteries with you.

     Brett

   I think what would rise to the top of any particular problems is engines running hot. The OTS guys that run ignition usually run anything but gasoline for that reason. Coleman lantern fuel, or even just Fox Super Fuel because they run cooler. High performance race cars gravitated to alcohol for the same reason. You need to run more fuel because alcohol ran cooler so you hade to run a lot more of it to get the same power. It sound attractive to C/L guys these days because of the cost per gallon, but in my mind, if it was all that acceptable and advantageous, we would have been running it a long time ago. I wouldn't mind seeing a model run and fly with it just out of curiosity to see what it sounds like and how it handles. One thing to consider is from a safety factor in just storing gasoline and handling it from your garage to the flying field and back. It is much more volatile, and I think ths aspect of it has been addressed and dealt with by the guys running iot in giant scale and large sport type models. It will be interesting to watch the situation and see how it progresses. For right now, I'll stick with what I know and understand.

  Type at you later,
  Dan McEntee

Hello
I got my sons old stunt trainer out and fitted the G5 plug to the Thunder Tiger 25 Pro and used the 75%Petrol with 25% oil mix and had my son Otto to give it a test flight. First thing we found was the needle was more sensitive and the exhaust note quite different, with a miss when too rich and sudden cut if set too lean.
It flew okay but had a 1 second slower lap times and we felt it was down about 20% on power with an increase in heat. Me and my sons then flew it till the silicon tubing grew too big and the clunk fell off which I knew would happen but we wanted to first compare it with glow fuel before swapping to the petrol mix.
On the plus side it felt like a diesel with a constant run once you got the needle setting right and it doubled the run time being so much leaner.
It had no tendency to run away and flew the maneuvers at a very consistent speed and no fuel draw issues.

The price of petrol and methanol are very similar now here in New Zealand in fact petrol is slightly more expensive due to fuel taxes but our initial testing was for a school science experiment that my son Max undertook.

A lot of the new generation gas engines are slightly bigger to make up for the power drop like a 37 instead of a 25 or a 55 instead of a 40 or 46 and they often have that big heat sink head.

Considered putting the G5 plug into a O&R 23 or 60 on a vintage model, so I can remove the need for a coil and batteries and not pop the head off with high nitro fuel . The heat build up and safety aspects may be offset by the neat sound difference and running style of Gas/Petrol.

Regards Gerald

Hello Jim Thanks for sharing your experience in running early gas/petrol spark engines and vintage models.
Its certainly an area I would like to experience more of having built some vintage models. I have run ignition engines on glow fuel to save the weight and complexity of running with points, coil and batteries but can see for the full experience I need to run them like they used to.
Perhaps the G5 plug will help in the learning curve in getting used to non-glow fuel.

Regards Gerald