Operating temp.

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21bangbang

21bangbang

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Decided to actually check just how hot my rc gets while bashing, and was shocked to see almost 270°F. Now I always thought a good temp would be 200-220 or so. After getting such a high reading, I fattened it up a touch, that led to poor running, but temps down around 230 (much better). I decided to split the diffrence on the H needle and ran again. This time I checked the temp in a few different spots on the head, and case. The temps varied by 20° on the head, and dropped about 70° on the case. After this I went searching for the proper way to take a reading. I found no consensus on where to read it or what a good temp is. Ive always gone off the plug, and they always look great, some last for years. So anyone here try tuning off temp, or just check to make sure its not to hot. Whats your process? What temp do you like to see? Ive never had engine failure so I guess my temp is acceptable, but perhaps im just lucky.
 
1Coopgt said:
For me I don't worry about it. You can tell if you're running it to lean and as you noticed when you were playing around with the screws the buggy ran like shite when it was to rich.

I just find the sweet spot and leave it.
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So you wouldn't be concerned with temps of 270°? From everything I've read thats way to hot, yet it does seem to be how it runs best. I can fatten it up a bit, and it still runs good, just not nearly as peppy.
 
I've never tuned off of temps, but I have checked from time to time. More so as a let's see how this ends up after I port it kind of a thing. I've not checked my dbxl, but my "play" saw I've checked a few times. It's a 346xp 50cc version. Box stock it (st spark plug) would generally be around 250* after porting I was down closer to 200* I attributed this to better airflow through the engine. I also did a few mods to the "can" muffler. Ironically after I ported it I ran it with an un molested muffler and it ran worse then stock. With temps close to 300* after the muffmods the temp dropped like a rock and performance was awesome. Now this was about three years ago in the fall. I would assume summer temps would be higher and winter temps would be lower. I normally don't have issues keeping engines running, and tune by ear.
 
Ya, my rc's always run well, and I can get a decent tune just by how it sounds. I just got curious how hot they were getting, and didn't expect the temp I saw. Only place to read the temp is the exhaust side though so wasn't sure if where you take the temp matters. I popped the shroud and the reading was almost 20° cooler on the opposite side.
 
Keep in mind the minute you chop throttle it will lose a hundred degrees F instantly. Best way to check is with a telemetry setup in real time. Of all the temp guns we used from cheap to high dollar. None of them matched what it was doing in real time. Best area to check is under the sparkplug. The range you are in is not issue IF the temps are correct.
 
TODD said:
Keep in mind the minute you chop throttle it will lose a hundred degrees F instantly. Best way to check is with a telemetry setup in real time. Of all the temp guns we used from cheap to high dollar. None of them matched what it was doing in real time. Best area to check is under the sparkplug. The range you are in is not issue IF the temps are correct.
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I do have the telemetry rx from futaba, perhaps ill get the temp sensor to see where im really at. I did put it on a milkcrate and throttle it as I read the temp. Wasn't quite a 100° change, about 60, but I didnt pin the throttle either.
 
21bangbang said:
I do have the telemetry rx from futaba, perhaps ill get the temp sensor to see where im really at. I did put it on a milkcrate and throttle it as I read the temp. Wasn't quite a 100° change, about 60, but I didnt pin the throttle either.
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Keep in mind that their temp sensors do not go high enough. If I remember Futaba maxed at like 350 F and Airtronics was less. I asked for something higher and both radio places said there is no need for higher. When I told them I was running gas both places said sorry. We will not be doing anything higher.
 
21bangbang said:
I know this. Not sure what your point is, care to elaborate?
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Oh sorry.
a nitro gets tuned by temp, smoke trail and sound. Most can tune by sound but still the odd temp reading is a good thing. The temperature is read by the glow plug.

A two stroke is tuned by sound and just on the rich side of the snap. Temp isn’t something that matters.

Hope that helps
 
Clubin said:
Oh sorry.
a nitro gets tuned by temp, smoke trail and sound. Most can tune by sound but still the odd temp reading is a good thing. The temperature is read by the glow plug.

A two stroke is tuned by sound and just on the rich side of the snap. Temp isn’t something that matters.

Hope that helps
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Gotcha, thanks for clarifying. Im not really trying to tune by temp. I was just curious how hot they were getting, so decided to check it out. My readings seemed high and inconsistent depending on where I took them, so was seeing if anyone knew what temps are acceptable, and the best place to take them.
 
I wonder if OBR has any info on that.I would think they must have some advice they wouldn't mind sharing.I am new to these small motors but I did deal with a lot of performance automotive engines and builds and temps are very important when dealing with tuning and extracting as much power from a motor as possible.Heat causes all sorts of failures seals break down,piston ring clearances are affected and even the different metals are somewhat affected by the heat.I don't know if the same can be said for these smaller engines but I would think it has a part to play in any combustion engine whether it be longevity of the motor or performance.
 
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Very new to this. I have a Rovan Baja 29cc. I don't know what the temperature is but when I am running it I have nearly no smoke. I am running Amsoil dominator at 25:1. It runs beautifully and as soon as I richen it up it sounds and runs very badly. Should I be worried about the lack of smoke? I always thought you should see a fair bit? Any advice will be greatly appreciated.
 
Quick update. Got a temp gun and checked the temperatures and at the moment its all good. Rovan recommend their engine temperatures should be between 93oC - 105oC (200oF - 220oF). After running it (hard) for 20 mins it was at 95oC, could probably be leaned out bit but its running really nice so it will stay like that. Cheers for help ?
 
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