TonyBuilder

My Feedback: (11)

so what is the safe operating temp for a 100cc gas engine?

Normal temp
high temp

thanks

TB

RickP

My Feedback: (2)

Curious as well. Does anyone know?
RP

av8tor1977

My Feedback: (6)

Offhand I would say 200 to 250 would be nice, with 350 being a never exceed redline. (Farenheit) Some would likely say never get near 350, though we use that as a useful redline with larger two strokes. Better safe than sorry though.... A little lean, a hot day, and/or a high power low speed maneuver can quickly turn a relatively safe temp into the meltdown zone.

AV8TOR

TonyBuilder

My Feedback: (11)

Anyone have success with spectrum heat sensor/ telemetry? I am getting good readings on the ground but once in the air it went bannanas saying my engine temp was 380 😳

TB

av8tor1977

My Feedback: (6)

I've seen 400 degrees while flying behind Rotax and Kawasaki engines. I didn't like it one bit, but lived to tell about it. (So did the engines, but the time at that temp was kept brief.)

AV8TOR

av8tor1977

My Feedback: (6)

Tower Hobbies sells a recording temp unit that you could use to double check/verify. I think it is pretty reasonably priced. Sorry; can't remember what it's called.

AV8TOR

av8tor1977

My Feedback: (6)

Found it. It's called "Venom". I have seen it recommended various times so I assume it works well. I think I will grab one myself as I only have telemetry on one of the aircraft in my fleet at this time. It surely is affordable...

https://www.rchobbyexplosion.com/Ven...p/vnel-104.htm

I just checked with an expert I REALLY trust about model gas two strokes, and he says for best power and engine life, use 300F as a reasonable redline with models.. It allows some room for error. Getting there will sometimes take a very well set up cooling system if flying 3D in high ambient temperatures.


AV8TOR

av8tor1977

My Feedback: (6)

Well, I went to buy one for myself, and that place was out of them, as is most everyone else. There were some unknown suppliers that at least didn't say "discontinued", but I didn't want to try one of them and perhaps get " burned". But then I found it on e-bay, new, from a guy with thousands of sales and a 100% rating. E-bay now has some pretty strict buyer protection, so I pulled the trigger!

We'll see.....

AV8TOR

av8tor1977

My Feedback: (6)

Just in case anyone is interested, I managed to get one of the Venom Micro Temp Monitors from "Nitro RC Hobbies" on E-Bay for $17.95. If you want one, grab it soon as most places no longer have it.

The only thing is, the instructions say to mount the probe down low; UNDER the cooling fins, which goes against every thing I know about measuring CHT's, which is to take your measurement close to the spark plug.. If anyone has experience with this unit and can clarify this discrepancy, I would appreciate it. Maybe for a nitro engine their way would be good, but not for a gasser???

AV8TOR

TexasFlash

..

TexasFlash

Growing up the only engine I ever had a factory temp gauge on used a connector under the spark plug as that's the hottest spot. But... whether the 300° reference is meant to be taken from the hottest spot (best reading) or the bottom of the cylinder (easier access) is the question I can't answer.I use a Spektrum setup under the top cooling fin and run 200-240ish on a DLE55 running with an alarm that goes off at whatever higher temp (250°F??) I set it at once I land and it heat soaks.

dubs1946

For the 3W85cc reccomended 100
centergrade from the manual.