Model Forum / Radio Controlled / Helicopters / August 2003

This is not specific to an OS .50, but it is generally accepted that DURING
OPERATION the temp is between 180 and 240 deg F (this varies greatly due to
engine, climate, fuel, cooling differences). This is also measured on the
cylinder opposite the exhaust, near the base of the head.

Examples:
TT 39 ran well at 215-220 in Idaho, USA (around 2300 ft MSL, 90-100 deg F
ambient air temp)
OS 70, still being tuned properly in " (190-200)
TT39 (same engine as above) at 180-190, running in Portland, Oregon (a few
hundred feet MSL, 70-80 deg F ambient air). Note, I will probably lean this
a bit more...
OS .12 CV R/C car engine, runs at 240 deg F.

Note, that all these temps were taken with a custom temperature logger that
records the temperature every 5 seconds throughout the flight.

-Dan

My opinon on this is:
Temp gauge does some things, and doesnt do some other things.

Temp values are not read as absolute values they are read as values of
scale to what your heli runs at best in mixtures.

In other words you need to know other than by temp guage what is too
cool, feeling the under plate of the engine while it is idling (not
turned off) will tell you if its too hot.

As you lean off and feel the temp also note the temp gauge, as it gets
warmer and leaner note the rate the gauge rises for each click in.
At the point of lean running the scale will start to increase rapidly
from hot to too hot in one click.
Once you have the engine operating at the correct mixtures back from
that and flying well and handling, then note the temp on the guage,
this now your indicator of how far off the temp is to what it should
be for best mixtures for your heli.

Again it is not an absolute test or values, it is and indicator of
change from the correct mixtures.
No point in telling you what mine runs at its of no use to you.
.
Temp guage saves bending down and fingering it to see, can have a peek
in hover at the gauge, also check for peak value before shutting off
to make sure it hasnt got too hot in the air away from you for some
reason (leaned off)
I let it idle high after landing while the rotors run down and have a
look at peak, low idle or shut off will ruin your peak reading as it
heats up for a period.
It also ensure the motor never goes over temp, half a min of highish
idle lets it cool down to well under before shut off so it doesnt rise
over peak ever and the meter holds true value to look at too.

I want my helicam motor to last me and it caries a fair load and runs
close to lean to do it and reduce vibes..
Id rather not give it anymore heat than it gets running.