What is the best way? I don't need fancy telemetry loggers, etc. Looking for a setup where I can hook up a basic loop temp sensor to something so that I can read-off peak engine temp upon landing. Any suggestions?

Venom temp gauge.

Here's a link if you need one: http://www3.towerhobbies.com/cgi-bin...&I=LXHUH3&P=ML

Thanks all. I knew there was no need to shell out hundreds of $$!

The batteries do not last long.
I soldered a lead to the battery clamp, and power mine with a single Nicad battery. It will operate a few months without the need to recharge.

Just a temp FYI. I've been doing some high temp run tests lately. So far I've managed to completely destroy an engine in 31 hours of run time, so temps are quite important. With a little work I think I'll be able to get that down to less than 10 hours. The intent is to destroy in order to determine how much for how long.

I looked at the specs on the Tower page and it did not give a temp range it is capable of. Anyone know this? I am thinking of other applications, maybe higher and lower than we expect our engines to run. Thanks.

Regards,

Richard

Peak is about 200C (400F) Well suited for our hobby.
The sensor is a glass bead NTC resistor, so it is easy to put a longer lead on.

What temperatures were you running? I know 200°C is ouch! in two strokes. Four strokes do not seem to mind that much. In my MVVS test engine (on the test stand) I repeatedly keptWOT until the cylinder temp whent past 200. It resulted in a heavily pitted wrist pin, due to the very low oil viscosity at these temperatures. No piston damage was recorded. Rings and cylinder in good shape as well.

How and where to is this gauge connected for best reading?

Pe,

Sent you a PM.

Spaceworm,

Try to keep the engine between 100C and 150C.

up in between the fins on the back side but towards the exhaust side of the head

I use the space between the uppermost cylinder fins, I also cover the fitted sensor with a short (3/4") piece of silicone tubing pushed between the ribs to keep cooling air away from the sensor, so it can do it's job of measuring cylinder temperature.

Thanks, w8ye and pe.

Hey, for the price of that unit it would be well worth getting one. I sure am going too.
Capt,n

http://www.rcsuperstore.com/ProductD...01&click=2

From 3W on temperature (HFE engine?)

Checking of Cylinder Head Temperature ( CHT)
To be able to check the cylinder head temperature ( CHT ) a thermo element has to be installed which
fits under the spark plug ( M 10 thread ). Optimum operating temperature range : 180°C - 220°C. In
this range piston, spark plug and combustion chamber will be free of remains. Maximum temperature
of 270°C should not be exceeded. During a certain time at full speed the temperature could be 250°C.
Colour of the spark plug should be : light or middle brown. A grey / gray colour is a typical sign for
over heating. Temperatures above 270°C are critical and over 300°C, piston can seize and could
completely damage the engine.
Temperatures below 180°C create remains ( carbon ) on the piston crown. Increasing remains hit the
cylinder and cause abnormal running noises ( knocking ) which will increase the load of the needle
bearings and can destroy them. Under extreme conditions the crankshaft can break and a complete
damage of the engine will be the result.

It sure can't be for a gas engine, and the HFE cannot handle those temps. Do that and you'll be saying C-ya to whatever the engine is in.

They've definately changed their numbers from what they used to publish. A previous high for a gas engine was around 120C. Since the cyulinders "pinked" close to that value it likely helped void some warranty claims. I'll strongly advise people not to run at and above 200C. Even allowing for differences in thermocouple reporting temps induced by deviations in location, 200 is HOT. Ther grey/grey spark plug color consistently occurs near and above 200C. Higher temps even change the color of the outer spark plug base. I burn up 3w's on a regular basis and all of it is done at lower temps than they are referencing. HFE can run hotter than gas but not that hot.

Here's the link http://www.3w-international.com/wp-c...emperature.pdf

I'll go there later. In the mean time, trust me, our engines cannot go that hot. I have not run an engine that did not suffer damage, some quite severe, at temperatures sustained at 200C and above. You WILL hurt your engine doing that. Perhaps they are using an engine different from those supplied to customers...

It seems like a person could do a pretty good check by flying for at leat 4-5 min....make a way out full throttle run, cut the ignition & glide the airplane in. Take the sparkplug out and if it is a tan or light brown color...you should be good to go. It is good pratice for a dead stick landing. I have over the years done many dead stick landings on purpose. You got to know how your plane is going to handle it first. Capt,n

No way would I want an engine of mine to run 200C. 180C is plenty for a high limit. (Never exceed) Like TOM says, 200C is close to death, especially if held for very long.

AV8TOR

So, get the Venom Smart Temp.. dont use the fail-safe system and plug it into a Rx free channel or Y wire.

One of my functions in temperature testing and anaylsis. If people want to waste a lot of time and effort trying to read engine temps from spark plugs, be my guest. I'll post a 200C plug pic a bit later. However, you cannot know what an engine temperature is by reading plugs alone. A data stream is mandatory. Reading a plug is best left for determining mixture settings. A perfect mixture setting indication on a spark plug is destroyed by elevated running temps.

So......what IS a good [cyl head] temp range for our 2-stroke gassers?

180 - 220 F. ???

Absolutely true. Reading plugs is no way to determine engine temp. The only good physical inspection method of reading two stroke engine temp is to take it apart and read the underside of the piston crown. Unless of course the engine is seized or has a hole burned in the piston. That's a pretty good sign of high temps....

AV8TOR