Gas Engine running temperatures
06-08-2015, 05:37 PM
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Gas Engine running temperatures
G´day all,
with the new Radio gear that has telemetry options, what is an approximate running temp range for our engines.
I have several gas 2 stroke engines, all in War Birds, so they have a cowl, from P-47 style to P-51. no obvious overheating problems.
I know there will be a lot of variables, just basic info,
I have fitted the telemetry gear to one of my models, the sensor is wrapped around the cylinder in the top cooling fin on the engine, sensor at the front, it was around 120 C to 130 C in the air, (air temp on the day was about 20 C) various throttle settings, then up high and back to idle, it eased back to about the 120 C range, taxi back in it got a bit higher 145 C then it got even hotter after I shut it down, which is basically what I expected.
thanks, Oldtimer
with the new Radio gear that has telemetry options, what is an approximate running temp range for our engines.
I have several gas 2 stroke engines, all in War Birds, so they have a cowl, from P-47 style to P-51. no obvious overheating problems.
I know there will be a lot of variables, just basic info,
I have fitted the telemetry gear to one of my models, the sensor is wrapped around the cylinder in the top cooling fin on the engine, sensor at the front, it was around 120 C to 130 C in the air, (air temp on the day was about 20 C) various throttle settings, then up high and back to idle, it eased back to about the 120 C range, taxi back in it got a bit higher 145 C then it got even hotter after I shut it down, which is basically what I expected.
thanks, Oldtimer
06-09-2015, 07:06 AM
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In the vernacular of the contemporary "cool"
You might find this interesting:
http://www.rcuniverse.com/forum/gas-...mperature.html
You might find this interesting:
http://www.rcuniverse.com/forum/gas-...mperature.html
06-10-2015, 08:30 PM
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The new radios certainly have more capability than we need. I doubt that most people will make use of all of it. But there are at least two items that are a real advance. Telemetry and voice alerts.Dont stay away from them and miss out on that. No need to be afraid it is all done for you
06-10-2015, 09:25 PM
#12
It is nice to have things available whether you need them or not. You can embrace as much as you want for your particular model. My sport Kaos model would not, but my big, complicated scale models do. Having my TX tell me that my air pressure is going down for my retracts, and then drop them automatically before I lose all pressure is a big deal. Or wiggle (accelerometer) my TX to toggle the voice modulation to call my maneuvers for competition practice. Plus, I love the all metal case of the Jeti, Does not feel like a toy, like most radios have for years.
06-13-2015, 07:20 PM
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G´day all,
I moved the sensor to the rear of the cylinder, still in the top fin, gave it a run, not nice, even hotter, like about 150 C to 170 C, now, I did expect it to be a bit hotter at the back of the cylinder. think I am going to have to fit some baffles to direct the airflow around the cylinder, any suggestions of how to do that will be appreciated, Model is an ESM Corsair, 85in engine is a 70cc twin. very happy with both model and engine, thought it was running great until I fitted the telemetry gear, well it is, just hotter than I thought it would.
took the cowl off, gave it a run in the back yard, open air, 18C, nothing in the way, still runs about the 150 C mark, fuel is stock unleaded, no ethanol, oil is 2 stroke air cooled engine oil, at 30mls per litre of fuel.
Oldtimer
I moved the sensor to the rear of the cylinder, still in the top fin, gave it a run, not nice, even hotter, like about 150 C to 170 C, now, I did expect it to be a bit hotter at the back of the cylinder. think I am going to have to fit some baffles to direct the airflow around the cylinder, any suggestions of how to do that will be appreciated, Model is an ESM Corsair, 85in engine is a 70cc twin. very happy with both model and engine, thought it was running great until I fitted the telemetry gear, well it is, just hotter than I thought it would.
took the cowl off, gave it a run in the back yard, open air, 18C, nothing in the way, still runs about the 150 C mark, fuel is stock unleaded, no ethanol, oil is 2 stroke air cooled engine oil, at 30mls per litre of fuel.
Oldtimer
Last edited by oldtimer4759; 06-13-2015 at 09:59 PM.
06-17-2015, 10:05 AM
#14
You'll need to block off some of that big opening in the Corsair cowling, and force the air to move over only the cylinder fins. Also provide an outlet, preferably one with a lip on it protruding into the air stream to create a low pressure area at the exit and promote good cooling airflow. If you have a lip on the outlet, a size of about twice the inlet should work out fine. You can't paint the area of the cowl you block off with flat black paint so it won't be noticeable.
AV8TOR
AV8TOR
06-17-2015, 01:23 PM
#15
You'll need to block off some of that big opening in the Corsair cowling, and force the air to move over only the cylinder fins. Also provide an outlet, preferably one with a lip on it protruding into the air stream to create a low pressure area at the exit and promote good cooling airflow. If you have a lip on the outlet, a size of about twice the inlet should work out fine. You can't paint the area of the cowl you block off with flat black paint so it won't be noticeable.
AV8TOR
AV8TOR
06-17-2015, 04:24 PM
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thanks for the info,
I have fitted the dummy engine in place, then closed off the top 3 cylinders area and the bottom 4 cylinders area, there is a dummy cylinder just in front of each engine cylinder, but it only covers about half of each engine cylinder, then I cut out the section of the cowl ring behind the cylinders, looking at the amount of in area, there is at least 2 or 3 times as much out area, I have also mixed some new fuel with more oil, 35mls to 1ltr, hope to give it a flight in the next couple of days, will take some pictures and report back.
Oldtimer.
I have fitted the dummy engine in place, then closed off the top 3 cylinders area and the bottom 4 cylinders area, there is a dummy cylinder just in front of each engine cylinder, but it only covers about half of each engine cylinder, then I cut out the section of the cowl ring behind the cylinders, looking at the amount of in area, there is at least 2 or 3 times as much out area, I have also mixed some new fuel with more oil, 35mls to 1ltr, hope to give it a flight in the next couple of days, will take some pictures and report back.
Oldtimer.
06-18-2015, 04:31 AM
#18
With all due respect , I believe your making a mistake in increasing the oil percentage of your fuel . Baffling the airflow to encompass the largest possible cooling fin area is your best bet . Any past research I've done with regards to oil content indicated that more oil will not translate into a cooler running engine . Too little oil ? sure , it'll run hotter as the inadequately lubricated components grind away at each other . But there comes a point of diminishing returns with higher and higher oil mix ratios , once the proper amount for lubrication has been supplied ,
06-18-2015, 05:10 AM
#20
thanks for the info,
I have fitted the dummy engine in place, then closed off the top 3 cylinders area and the bottom 4 cylinders area, there is a dummy cylinder just in front of each engine cylinder, but it only covers about half of each engine cylinder, then I cut out the section of the cowl ring behind the cylinders, looking at the amount of in area, there is at least 2 or 3 times as much out area, I have also mixed some new fuel with more oil, 35mls to 1ltr, hope to give it a flight in the next couple of days, will take some pictures and report back.
Oldtimer.
I have fitted the dummy engine in place, then closed off the top 3 cylinders area and the bottom 4 cylinders area, there is a dummy cylinder just in front of each engine cylinder, but it only covers about half of each engine cylinder, then I cut out the section of the cowl ring behind the cylinders, looking at the amount of in area, there is at least 2 or 3 times as much out area, I have also mixed some new fuel with more oil, 35mls to 1ltr, hope to give it a flight in the next couple of days, will take some pictures and report back.
Oldtimer.
Sincerely, Richard
06-18-2015, 04:46 PM
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hello Richard,
I fitted the Temp Sensor to the rear most cylinder, the one closest to the firewall. but I have since fitted a second sensor to the other cylinder, cant run them both at the same time, but I can swap them over quite easily, will check each sensor on the ground first, then fly it, swap them over and fly again, hopefully that will happen over the next couple of days.
thanks, Oldtimer
I fitted the Temp Sensor to the rear most cylinder, the one closest to the firewall. but I have since fitted a second sensor to the other cylinder, cant run them both at the same time, but I can swap them over quite easily, will check each sensor on the ground first, then fly it, swap them over and fly again, hopefully that will happen over the next couple of days.
thanks, Oldtimer
06-19-2015, 03:12 AM
#22
hello Richard,
I fitted the Temp Sensor to the rear most cylinder, the one closest to the firewall. but I have since fitted a second sensor to the other cylinder, cant run them both at the same time, but I can swap them over quite easily, will check each sensor on the ground first, then fly it, swap them over and fly again, hopefully that will happen over the next couple of days.
thanks, Oldtimer
I fitted the Temp Sensor to the rear most cylinder, the one closest to the firewall. but I have since fitted a second sensor to the other cylinder, cant run them both at the same time, but I can swap them over quite easily, will check each sensor on the ground first, then fly it, swap them over and fly again, hopefully that will happen over the next couple of days.
thanks, Oldtimer
Sincerely, Richard
06-19-2015, 03:49 AM
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hello Richard,
slight misunderstanding, it is a horizontally opposed twin, just one cylinder is mounted slightly in front of the other. both cylinders fire at the same time, I think the Saito fires one at a time.
Oldtimer.
slight misunderstanding, it is a horizontally opposed twin, just one cylinder is mounted slightly in front of the other. both cylinders fire at the same time, I think the Saito fires one at a time.
Oldtimer.
06-19-2015, 03:56 AM
#24
Sincerely, Richard