Originally Posted by orthobird

James, i meant 170 to 200 within minutes of start up. that is usually temp i see on my telemetry before taking off. once up in air, like you said, temps are 200s, not higher than 270 or 280.

over 300, i think, is too hot.

I see where you corrected yourself. Im pretty much the same line of thinking, get temp close to 200 and take off. Doesn't take to long to get there.

Where do you place your thermocoupler? I place mine on the back of the head at the last fin before it changes direction on the top of the cylinder dome.

Yes, same here. this was advice given to me by PE.

Y'all are over thinking it. Seeing a temperature isn't going to tell you if you are lean or rich. Do a plug check to see if you are rich or lean. Get rid of that garbage, and be happy!

Onboard temps and telemetry sure as hell aren't going to make you a better pilot!

I look for 220F after flight. That is about the max I want to see, after flight. In flight I see 350F. My engines haven't melted, and they run puuuurfect! No telemetry, just a simple IR gun, and checked with onboard digital readouts, with the T/C on the top fin, backside. Hearing those annoying beeps in a spin would get on my nerves pretty quick.

I'm running Spektrum telemetry with the temp sensor between the top two fins, backside of the the right cylinder. I don't think shooting it with a temp gun after landing tells much, because I'm seeing the temp drop from over 300 to about 270 during the landing approach.

I'm not trying to tune the motor based on temp readings. I know the low needle is rich by the sound I get during part throttle. I've been leaning the low needle with each fllight, trying to get it in line. This isn't an engine I would dare tune while running! But I wonder if leaning the low needle has made it too lean on the high end; I haven't been touching the high needle.

Reguardless, I'm adding baffling . . .

Well, I baffled the engine bay by the the example I saw by, I think Earle? Anyway, the results were quite dramatic; temp dropped from 350*F+ to the low 240's for the whole flight. Almost too cool now! Surprisingly, this baffling also seemed to make the engine run richer. So I've got some tuning to do.

Here's what I came up with.

can ya post a pic looking down from the top?

Originally Posted by Bill Vargas

can ya post a pic looking down from the top?

Here's one, Bill. I used screws to make parts of the baffles removable, so servicing the spark plugs would be easy. Not as pretty as yours!

Thanks Low Cal,,, thats an older pic of a 3.1 SX compy that I used to have but got rid of it in favor of an EF 125" Extra. The monocoat trim checkers were applied over the lite ply baffle plates with a dusting of 3M77 spray prior to application and yes it held up just fine with no issues. What caught my eye was your back baffle plate and has me thinking about doing the same as you did

Low Call, and Bill. i was flying my 119" extra with da 170 and muffs last weekend. i have baffles, posted on my build thread.
i removed the tuned pipe.
i was flying her thru basic IMAC, then after the sequence, i was doing some hovering and tail spins, and knife edge, then, all of a sudden, i got a deadstick.
outside ambient temp was 70 degrees.
when i got to her, i did not check the temp, but it was very very hot.
the next day, i got advice from Josh Price, i obtained a coke can, split it, and made a louvre, then i placed this in front of the exit holes on the bottom of the fuselage.
i then flew her two more times, and not a blip. felt real strong.
i used my flash temp reader, and the cylinder head temps were 180 on one side and 220 on the other side. don't remember which one side was hotter. i also checked my other buddies twins, and they all had different temp from one side to other. i think this is normal, so far as i know, one cylinder runs hotter than the other side.

it would be interesting if you collect data for one cylinder head, and then move the sensor to the other cylinder and see what you get.

I suspect a deadstick I had last year (that resulted in the loss of the airframe) was caused by overheating the same DA150 I now have on my 119 Extra. No baffling or temp telemetry back then, so hard to say, but likely.

I'm not using any louvres, but I would if I were still having high temps. On another plane, I used balsa triangle stock covered with Ultracote.

Orthobird, that DA170 and 119 must be a dynamite package! The DA150 on standard muffs pulles my 119 out of a hover fine, so I can only imagine . . .

I visited Shreveport once; you folks sure have a lot of trees! Bet you had to cut down a few to build that field.

Hmmm, louvers will most definately help and are very easy to make,,,

Originally Posted by Low_Cal

I suspect a deadstick I had last year (that resulted in the loss of the airframe) was caused by overheating the same DA150 I now have on my 119 Extra. No baffling or temp telemetry back then, so hard to say, but likely.

I'm not using any louvres, but I would if I were still having high temps. On another plane, I used balsa triangle stock covered with Ultracote.

Orthobird, that DA170 and 119 must be a dynamite package! The DA150 on standard muffs pulles my 119 out of a hover fine, so I can only imagine . . .

I visited Shreveport once; you folks sure have a lot of trees! Bet you had to cut down a few to build that field.

The field is in the middle of a cow pasture. There was only two trees remotley close and you had to work to hit them. They're gone now. The guy that owns the land the club flies over decided to put a 40 acre pond right smack in the middle of the pasture they fly over. And yes, a DA170 has insane power on the 119. I flew mine with the 150 on mufflers, and I'm with you. More than enough power for that plane.

Originally Posted by BOSSIER_ROB

The field is in the middle of a cow pasture. There was only two trees remotley close and you had to work to hit them. They're gone now. The guy that owns the land the club flies over decided to put a 40 acre pond right smack in the middle of the pasture they fly over. And yes, a DA170 has insane power on the 119. I flew mine with the 150 on mufflers, and I'm with you. More than enough power for that plane.

Right on! Our field is in a similar location, minus the pond. An extinct pasture, surrounded by active cow and horse pastures. We're leasing from a land owner that has just decided to sell the property, which has created some drama in the club!

Cool, having that pond gives you some float-plane opportunities! Just keep a fishing pole handy to reel your plane in when needed!

Loving the 119; I also have its little brother, the 72" which flys very nice for its size.

Originally Posted by Low_Cal

Right on! Our field is in a similar location, minus the pond. An extinct pasture, surrounded by active cow and horse pastures. We're leasing from a land owner that has just decided to sell the property, which has created some drama in the club!

Cool, having that pond gives you some float-plane opportunities! Just keep a fishing pole handy to reel your plane in when needed!

Loving the 119; I also have its little brother, the 72" which flys very nice for its size.

That's one of the down sides. We can't intentionally use the pond for flying off of. He really wants us to pack up and move.