I see you edited your previous post with more info...

For the MM it will go into thermal shutdown around 190F. I prefer to not have my electronics go higher than 130F. The Feigao motors will run hot. you shouldn't let it go over 200F or you risk damage to the motor.. I'm not really sure about NiMH batteries, I haven't used them in so long I don't even know what is to hot for them. I would imagine if you get over 130F or so in them you are on the hot side.

Yes, for sure get a heat sink/clamp for the Feigao. What Feigao are you running? L.... XL? What wind.

It sounds like you are running 2 6 cell NiMH packs. You don't have to worry about a Low Voltage cutoff on NiMH. You only need to worry about that for Lipo packs.

i love it so far...here is my set up
hot bodies 1/8 truggy with a 15 tooth pinion and 50 tooth center spur
3600 Nimh 6 cell packs running in series so 14.4 volts
feigao 8XL motor with the mamba max ESC
i dont have a fan on motor or esc
in 5 minutes the highest temp was 85 Ferienhieght on the ESC and around 70 for the motor and battery
i think i may get about 10 minutes hopfully..i am thinking either later getting a 3s or 4s lipo pack or 2 5000 mah NiMH packs...but im hoping it dosnt get much hotter..because 85 is really good i soppuse and if thats after 5 minute i would figure it was prolly peaked out in getting hott