RE: NITRO content vs. Engine size?
balsa eater quote-"The addition of lots more nitromethane means the more mechanically challenged type person you are the easier and more wide band will be the tuning of the glow engine
This is because the engine would getting its oxygen from a fixed source the fuel itself at a steady rate rather than from the air which can change hourly in temperature and humidity and require constant tuning changes
Also using higher nitro will gain some extra power as a side benefit and importantly it will be more the power will tend not to be so peaky like zero nitro fuels and a noticeable gain in low end torque at the lower RPM such as is needed in 3d work"
We have a couple of guys at the field that have swithched to Byron 30% and use an OS F plug in all their engines and have nothing but good news to report. No deadsticks, easier tuning, etc... He quoted to me what you stated-"Oxygen from a fixed source, the fuel itself, at a steady rate rather than from the air which can change in temerature and humidity." I might have to try this myself.