RE: Heli fuel in the MGT 8?
It works. you'll have to retune all 3 needles however, or it'll like to stall. temps are fine - it's a hotter running engine anyways. i routinely see temps that would melt a smaller traxxas 3.3 for instance.
I haven't used heli fuel, but have used high oil content fuels (synth oil) with no ill effects. wasn't as "punchy" since the oil displaces methanol, but ran more predictably once tuned. I would not use a higher percentage of nitro + a high percentage of oil... displaces too much methanol... nitro is what creates the flashpoint for ignition, but methanol is what sustains the explosion. too low and it won't ignite, and too high and it will fizzle and stumble after ignition. Run a hot plug, btw with heavy oils...