Originally Posted by AKNick

Gotcha. Maybe these fins are too far apart to make the tubing pinch on the wires like you talk about. I'm using heavy duty tubing too.
Where does your sensor end up at (orientation) the front?

My sensors are at the back side of the head. Usually the hottest area of the cylinder because it has reduced airflow.

BTW, Futaba and O.S. has this very nice telemetry interface called EM-100. As far as I know, it is not yet commonly available. And one of the accessories for this interface is the temperature sensor ST-01 for combustion engines. It has a mounting eye for a screw. See the manual page 8. There are another nice sensors ...

https://www.os-engines.co.jp/OS_prof...EM-100manu.pdf

Just get the sensor in good contact with the cylinder head and use a small amount of RTV gasket seal to hold it in place. I have had these on my DA 200 since 2013 with no issues.

Originally Posted by eheliflyer

Just get the sensor in good contact with the cylinder head and use a small amount of RTV gasket seal to hold it in place. I have had these on my DA 200 since 2013 with no issues.

Ok, Thanks

Here’s what I ended up doing. We’ll see how it performs.
-Got a piece of thick silicon fuel tubing that’s about as long/deep as the cooling fin.
- folded the sensor and passed it through the middle of the tube
- rebent the sensor so it lays flat against the head, sort of triangle shape.
- added some hi-temp copper RTV around the sensor and in the sensor wires where they pass through the tubing, and a little smear on the sides of the silicon tubing.
- with the tubing as long as it was I ended up using a zip tie (not the lacing wrap in the one pic) to firmly hold the sensor to the cylinder head until the silicone dries, thus eliminating any silicone insulation from the sensor to the wall.
-cut the zip tie and presto. Seems to hold nicely. We’ll check back later after I get some run time.

One thing I ran across and maybe someone can provide some insight to is thermal glue. No idea if hey make it resilient enough for 200C like the sensor or what? Ideas?

I ran my engine today. Temps were equal on the ground at idle. Running up the right cylinder was getting hotter (20-30deg). In flight was fine under half throttle running around 210-230F, and very close to each other (within 10deg). Approaching half throttle the right cylinder would start to get 30-40 degrees hotter. I set an alarm for 250. Correct me if I misread other threads that the cylinder temps should be under 250 and not more than 300? After both cylinders exceeded about 250 I landed and tweaked the HSN a bit richer, same result. So I opened it up some more, same result. When I do a below half throttle cool down lap or two it does just that - cool down
Both cylinders have craft foam baffles directing air to the cylinders.
It wold seam like this is a mixture issue as below half throttle they are both spot on, then near half and above they heat up. The right cylinder being the hottest (rear) would tell me cooling issue to that cylinder. Engine has a couple gallons through it now.

My questions:
1- what’s the operational temperature range suppose to be?
2 - what’s should be my alarm temp?
3 - insight on the temps going up quick after half throttle.

I should have made it stupid rich to see if it changed. I only moved the needle 1/8 turn richer. To give you and idea, if I opened up the throttle to dive and pull up to a pop top the temps would increase 50deg. I know... sounds lean. But it doesn’t act like it in flight. Pretty oily exhaust on both pipes too.

Let me know what you guys think. I appreciate the insight/help/suggestions.

First off, can your transmitter switch from celcius to Fahrenheit? My transmitter don't from what i can tell. It seems my 16SZ only does celcius. And one cylinder usually runs hotter on a twin from my experience unless you really do some creative baffles.

Originally Posted by jamesrxx951

First off, can your transmitter switch from celcius to Fahrenheit? My transmitter don't from what i can tell. It seems my 16SZ only does celcius. And one cylinder usually runs hotter on a twin from my experience unless you really do some creative baffles.

I was able to convert from Celsius to Fahrenheit in the 18SZ.

Can anybody confirm what my temps should be?

From what I've been reading:

200-280F Ideal Operating Temperature.
300F WOT and in a hover.
330F Cool that sucker down. ALARM SHOULD SOUND
375F you have pegged redline
380-400F + your engine will likely shut down
430F Detonation

This sound right?

Originally Posted by AKNick

From what I've been reading:

200-280F Ideal Operating Temperature.
300F WOT and in a hover.
330F Cool that sucker down. ALARM SHOULD SOUND
375F your have pegged redline
380-400F + your engine will likely shut down
430F Detonation

This sound right?

Then your temps are really good and i would retune the engine so it's not rich. I shoot for 300F or around that. If I hit 350 on an upline full throttle I will go from there to see if over all temps are higher than I like or just on upline. I try to stay away from 350 or higher.

Just remember you are reading at the hottest section of the cylinder with the exception of the spark plug port. The least airflow is in that area.

Pictures of my sensor mounting.

Thanks for the input. I'll probably reset my temp alarm for 330F along with opening up the bottom cowling a bit more.

Originally Posted by AKNick

Thanks for the input. I'll probably reset my temp alarm for 330F along with opening up the bottom cowling a bit more.

I will have to try and figure out if my 16 can convert to farhient but inset my alarm at 175C. Which is 350F ish.

Thanks for posting your experiences on this subject. I’m working on an Extra 330 right now with a DA70 and the Spektrum temp sensor. When I first got it I was trying to figure out just how to mount the thing. The use of Permatex and silicone fuel line looks like it’ll work great for me as well. Thanks