Connecting a temp sensor for telemetry

[ryan_m]

I'm just starting to experiment with telemetry settings a little bit, and wanted to ask the experts here the best way/place to connect a temperature sensor to the motor. I have an EME70 twin that I want to mount it on. I gather the back of one of the cylinders is probably the hottest spot, and so I had planned on mounting it there. Is that correct? Towards the top of the cylinder, near the combustion chamber was my plan.

The temp sensor is designed to be bolted on, and is a small ring mount terminal. I had thought about drilling a small hole in one of the cooling fins and bolting it on directly to the fin. Are there any better ways?

This is the sensor:

 

[nearhigh]

I'm just starting to experiment with telemetry settings a little bit, and wanted to ask the experts here the best way/place to connect a temperature sensor to the motor. I have an EME70 twin that I want to mount it on. I gather the back of one of the cylinders is probably the hottest spot, and so I had planned on mounting it there. Is that correct? Towards the top of the cylinder, near the combustion chamber was my plan.

The temp sensor is designed to be bolted on, and is a small ring mount terminal. I had thought about drilling a small hole in one of the cooling fins and bolting it on directly to the fin. Are there any better ways?

This is the sensor:

this a picture of how I did it. Drill hole and tapped to size of bolt You use, thread lock and nut. works great

 

[Robbins]

If it were my choice, i would mount it on the exhaust flange side.

 

[ryan_m]

I could do that, but curious as to the reason why you would do that? To me it seemed most logical to mount the sensor where it wouldn't be getting cooling air directly on it, though I suppose moving the probe to the bottom/back of the cylinder is much the same, not much air there either and it would be near the exhaust port then.

 

[ryan_m]

this a picture of how I did it. Drill hole and tapped to size of bolt You use, thread lock and nut. works great

that's what I wound up doing as well. Mounted on the back of one of the cylinders, not in the direct path of the airflow coming in the front.
I've been seeing temps in the 250-315 range with it right there. Got nine flights on it this weekend with the telemetry installed. May need to buy a couple more of these sensors and install in my other gas planes. Love having the direct feedback of what moves cause the engine to heat up. Flat spins were one of the worst I saw this weekend, and knife edge spins too.

 

[nearhigh]

that's what I wound up doing as well. Mounted on the back of one of the cylinders, not in the direct path of the airflow coming in the front.
I've been seeing temps in the 250-315 range with it right there. Got nine flights on it this weekend with the telemetry installed. May need to buy a couple more of these sensors and install in my other gas planes. Love having the direct feedback of what moves cause the engine to heat up. Flat spins were one of the worst I saw this weekend, and knife edge spins too.

Do You have baffles for cooling? The black vertical piece in my picture is the back part of my baffles. I have front baffling glued to cowl to direct air over and through the fins. Temps staying below 275 degrees.

 

[ryan_m]

Yes, I have baffling directing the air from the front over the cylinders, but nothing towards the back to curve it back down around the backside. I'll be adding that in a few weeks I think.

 

[nearhigh]

Yes, I have baffling directing the air from the front over the cylinders, but nothing towards the back to curve it back down around the backside. I'll be adding that in a few weeks I think.

yea needs baffling in back to direct air. if not air just go past the cylinders. front and back baffling work together.

 

[dhal22]

I need to check out temp telemetry. Would be a nice input on a hot summer day.

 

[jon595]

You would be surprised. I did a before and after test with rear baffling and it told me I dropped 40 degrees. My spinner is no longer warm to the touch after a flight.