Head temp

[3-d expert]

What the optimal head temp for a heli engine?

[cyhyam]

220 - 225F, above that you will start thermal run-a-way, unless you are using Cool Power 30% the oil in it will hang in there up to 245F before thermal run-a-way. These measurments are taken in flight with an on board temp sensor placed into the cooling fins of the head. I have sensors on all my helis, 32, 50, 61,, some are around the top of the cylinder, but all read the same range. I would caution against using a remote hand held temp sensor for accurate readings.

[3-d expert]

I use Wildcat and because of the type of oil in it and the higher temp threshold it can hanlde much higher themps than Cool Power.

[GWRIGHT]

what are you basing this statement on ? How did you collect the data ont he temp. differences in the oils? I'm curious

[cyhyam]

Gary,
Was your question for me?

[GWRIGHT]

no,.. the question was for the "3d-expert" about oil quality and temp stability. I was asking, as I have tried every fuel that's been available in the last 12 or so years, and i've flown CP30% for the last 10,.. although I occassionally buy a gallon or two of something else to compare with. I ALWAYS go back to CP30.

[donlynn]

Gidday

I made a really good temp gauge out of a bc327 transistor ,join two of the legs together and hook directly up to the diode test on your multimeter,works very well,test it against a known good temp gauge in the oven first.
mine is very approx 2.4 mv down per increase degree C.
It will cost you the transistor and a piece of wire less than $2.
If it doesn't go swap the legs or the wires around,
I know it works very well!
I have used one into a amplifier ic driving a wee meter driven by a 9v batt, lasts a good 3months plus per battery as the CHT on my Pterodactyl Ascender microlight for about three years now.
Regards Don