Hello guys, I have finally picked up my first Helicopter. The TT Raptor 30 V2 ARF. I have been into R/Cs Cars/Trucks for over five years so I know my way around a nitro engine and how to tune them. But on the trucks we use a temp gun to check the settings of the engine. Is a mounted temp guage needed on a helicopter? Or what?

A temp gun should work fine on the heli as well. A lot of guys just put their finger on the backplate and count the time you can hold it there. 3-4 seconds or more is what you're looking for after flying it. I can hold my finger on my TT50 backplate forever at idle, and about 9-10 seconds after flight.

Ok, I can understand the concept of using your finger to check engine temperature. But everyone has different tolerances to heat, so its not an accurate way to check it.

Is there an actual temperature range that a heli engine should operate at?

My OS 50 Hyper just runs hot. If I richen it up just one click, it just doesn't run well. I can even see fuel spraying out the exhaust but I can still only hold my finger on the backplate for 1, maybe 2 seconds.

Ya, I would perfer a temp range for my TT .39 instead of the finger trick...

Try running it leaner with a little lower throttle curves. Say 95, 70, 50, 70, 95 instead of 100, 75, 50, 75, 100

Barracudahockey,

Where do you have your needle set on your Hyper 50? I had to lean out the idle and the main is 1 or 2 click past 1 turn open. It idles perfectly without the blades turning and has nice throttle response. I'm running CoolPower 15% Heli fuel with OS#8 plug. The engine will richen up when the tank is below half, I expected it to lean out below half.

Just afraid to run it to lean, I already put a new piston and ring in it from running it with Omega 15%.

I almost hate to answer this question because so many factors effect needle settings.

The short answer is just short of 1.5 turns, maybe 2 clicks less than 1 1/2.

My 50Sxh on the same fuel/muffler combo ran just over 1 turn open. I'm not surprised at the difference as the hyper has a bigger throat, so more air means more fuel, more power.

I'm running CP 15 percent with a stock TT muffler. I fly at or near sea level.

Just a recap, the following issues effect needle settings.

Fuel
Muffler
Density Altitude (air pressure, elevation, temp and humidity)
Gearing (though if we are talking R50's the gearing is identical)
Blades
Pitch/throttle curve
Cooling efficency (head, fan, airflow etc)
Phase of the moon, high or low tide and position of the out house relative to the front door all have some effect as well

So what runs well here in Jacksonville when its hot and humid with 15 percent may be a full turn or more different in Denver with a pipe and 30 percent even in the same heli/motor combination.

If you can get a temp guage (I got one from the pawn shop for $40 (original $100) and use that. Or you can buy the little blue one (forgot who makes it) that is used for R/C things.

I run my helicopter at 210°. If you call HeliPros (1-877-435-4776) they will tell you the exact same thing. It doesn't have to be right on 210°, but you can be close to that (210-215°). I wouldn't go over 220-230°.

There is a running temp that all engines should run around. If you don't have the right heat then you don't have the right expansion that the cylinder and piston need to run efficiently. That is with a car engine. You can see if and engine is too hot, then you would get poor performance and if it's too cold the same would happen.

Just run them around 210° and you will be fine. I suggest getting a temp guage. Since I got that one from the pawn shop, I don't know what I would have done without it. I never knew I would use it as much as I am!

I sincerely hope that helps

~Michael~

I already have the Raytec one for my R/Cs...

Well, since you say you have one, what temp are you running?

~Michael~

Have not even flown the thing yet...

I have a friend bringing a temp gun this weekend. I'll check it then. Thanks, it give me a ballpark figure now to work with.

This all depends of course on where your taking the measurement.

The back plate will be cooler than the head etc.

Problem with takin head measurements in a timely manner with a helicopter is half the time the engine head is shrouded by a cooling fan shroud.

Wouldn't that fan mess with the temp guage, giving a false reading?

Well, you wouldn't have the fan running that much if you're just at idle. I have had to problems with just putting the temp. guage right up to the head and I get a great reading. My temp. gun can read up to 20ft. but I just get close to where I know it's accurate. Now, if you were checking the head temp on a plane with the engine running, then the prop could have signifigane impact on what reading you will get. But, if you get close enought to the head, then you should have not problem. There is usually some part of the head you can measue the temp. Sometimes I'll just take off the canopy, and check right beside the glow plug.

To me, there is not need to take the engine temp reading on the backplate. You really need to check the head, and side case temps. The backplate will not be the hottest part of the engine for obvious reasons, but the head will, since that is where all the action is taking place (explosion, movement of cylinder, etc.). Like I said, I was talking about a "running temperature" of around 210-215° you should have the head be running. If not at this temp. proper expansion will not take place.

How that helps

~Michael~

I use a infra-red lazer temp gun on my 60 & 90 heli's (Stanley brand sold at Sears). I usually spend the first tank full of fuel tuning in the engine and trimming and as soon as the heli is spooled down from the first tank, I measure by pulling the canopy off. It only takes a few seconds and I put the lazer dot right on the glow plug. Depending on humidity (which lately has been as high as the temperature), I verify if my tuning is close to the preferred 200 to 225 degrees farenheit. At that point I make a final adjustment.

Note; Just because the temp of the engine head is where you're adjusting to, it might not always be the optimum flying setting. I've tuned to get the best flying performance and found the engine was in the 240 degree range because it's hot and humid. Left the settings alone, came back that evening with the same exact settings and got temp reading of 210. So there's many factors, but it's better than tuning to a meltdown and by checking the temp this won't happen as easy.

Mike
Raptor 60 & 90
OS Engines
Futaba Electronics
Cooper 30% Fuels

Check the temp tonight and I was running 196-200 degrees.

To dispell a great deal of misinformation about tempreture in model engines, including helicopters:

A lot of misinformation exists out there about what tempreture heli X or engine Y need to run at, same thing goes for cars. First of all, a great deal of the info out there is only part of the equation. For example: If Joe claims that his Raptor runs the best at 210 degrees, that's great, but what is not always being discussed is what exact fuel, what plug, what gear ratio, what blades, what altitude, what blades, what muffler, any head shims?, what ambient air tempreture, what relative humidity and barametric pressure.
Each and every one of those above listed items has a direct effect on how needles are set and what tempreture the heli runs at. Some of them have more influence than others and they all have a cumlative effect on the tune. Bottom line is "Joe" is doing great at 210 under what ever conditions he's experienced. Now, Mike, which has an exactly identical heli setup right down to the last nut and bolt, may never be able to tune to 210 degrees. Why? environment, fuel, altitude, weather conditons, etc may make it impossible for him to tune it to even 250 degrees.

Moral to the story; forget tuning the heli engine with a temp gun (or any engine for that fact) and use your ears. In a max vertical climbout, do you hear a frying egg sound or a high speed rattle (every engine and pipe sound a bit different), or does the engine sound like it's sagging out after the first few seconds? If you do, then you richen the high speed needle up. If it is boggy and takes awhile to clean out, then its too rich. Tune the engine to where it is happy, it will decide what tempreture to run at.

Asking someone what temp something should run at and the answer is 210 -215, is like saying to cook all food at 300 degrees. It does not work that way, period.

Another factor to an accurate temperature reading with a temp gun is whether you are using it correctly. Sure a temp gun may work from 20 feet away, but you are not getting the actual reading where the red dot is. You are getting a reading of the ambient temperature of the air. Also, the temp gun will only give an accurate reading when taking the reading from a DARK surface and very close to the heat source. I've proven this to many people.

Just try this test with your temp gun:
Turn the furnace on in your house and let the ducting get nice and warm. Take a piece of black electrical tape and place it on the duct. A one inch piece will do. Now from about one inch away, take a reading on the duct itself, then take a reading off the black tape. You'll be surprise how different the readings are. Then take readings from further distances, the farther away, the less accurate the reading is.

So, most engine cases, the head and plug are silver in color and will not give a true temperature reading.