What is an expected motor temperature and too hot temperature?

[ryan_m]

Good stuff Orthobird and Bunky. As for the lean condition, I richened both needles a tiny bit after noting the plug colors. I had not attempted a restart after the dead stick as I suspected she was running lean. It had been difficult to get started, requiring about 4-5 cycles of choke until pop, unchoke, flip until fire to get it running. After richening up both needles the starting got easier. I have 9 flights since getting the temp sensor and baffles installed. I need to baffle the back of the cylinder too probably to force the air down over the back a little bit more. But the motor is starting better and running very well. No more quitting. And the temps I see are right in line with what you describe orthobird. I noticed knife edge will heat it up a bit, to around the 290 range. Flat spins push it up to 310 pretty quick, those surprised me with how quick they heat up the motor. And low-mid throttle cruising will drop the temp 30-40 degrees very quickly, like a landing approach. I'll pull the plugs again when I pull the cowl off for baffling the back of the cylinders some more, but I suspect they are just about right now. The motor doesn't fade on uplines. Does change a tiny bit when doing a slow mid throttle roll. Can't recall exactly what it's doing, just a hiccup I think and then is fine again as it rolls on over.

 

[combat chicken]

Sounds like you are a little heat soaked. 310F really isnt bad, it isnt good either. Air exit should be around 3x greater than air inlet size. If you have a can tunnel in the airplane, open it up to allow air to escape.

Doing a plug check will yell you if your H needle is too lean. You say it quit on you, but hopefully, you've not tried to restart since? Of you have, it isnt a huge deal.

Start the engine and get it to operating temps, and on a High speed run up, shut the ignition off. Pull the plugs and check the color. Too light of color, indicates lean, which is what I'm suspecting. But you don't want a dirty, dark chocolate color, almost black in color on your plugs. That indicates a rich condition.

Your baffling can be stellar, and you can have all the latest and greatest fandangled gadgets and gizmos. Over heating an engine even with that stuff going off in your ears, while you are flying, can be very distracting, atleast it would be to me. But engine temp telemetry will not tell you that you have a lean condition causing the overheat. It will drive you up a wall, and you will constantly be modding your baffling and air outlet.

Everyone knows I absolutely cannot stand engine telemetry. If you listen to the engines performance, it will tell you what is going on. I listen to it on long uplines (high needle), mid throttle half rolls (low needle). Throw the tach back in the tool box, dont get it out. I get an engine to run good on the ground, then I spend a few flights tweeking the needles. Once you set them, you shouldn't have to touch them for a long while.

Also, oil is oil. There is no "whats the hot ticket" oil or "best oil". Sthil Ultra HP is awesome. I haven't used Red Line. But I do understand that it is good too. Pick an oil and stick with it. Dont change unless you cannot get your favorite oil before you go flying. My engines have a light bit of carbon in them. I dont go for the cleanest combustion chambers. I want my engines to last me a long time.

@Bunky.F.Knuckle I too use the Sthil oil. Question? I mix at 35 to 1 using 93oct fuel for my DLE 30cc and SPE 43cc. The instructions on the Sthil bottle recommend 50 to 1 and that is what I run in my chain saw which is as you know chain saws run under high load and high rev with not much air movement, and I have never had an issue when operating it. Thinking of going to 50 to 1 on the birds. Your opinion on doing this. (Others may chime in too)

 

[49dimes]

Did you know 3W recommends running an ashless oil (32:1) for 3 or 4 hours before going to 50:1 synthetic?

Well....No Joey, I did not know that....Tell me more!....

Ok Timmy; I will tell you more young fella!

Friction can be our enemy and our friend! Did you know that Timmy!?

No Joey!! Wow!! How can it be both? I'm confused??

Well Timmy....When an engine is new it has the basic tolerance required to allow "friction" to be our friend by honing and lapping metal surfaces so that they "mate" with each other!

MATE with each other!?!? You mean like how I want to do with my girl friend???

Well.....NO Timmy! Not in that way little fella! haha .

I mean to conform with each other and NOT spooning! This will reduce friction and allow "less oil" to do the same work as "more oil" as when the engine was brand new!

Focus Timmy!

 

[Bunky.F.Knuckle]

@Bunky.F.Knuckle I too use the Sthil oil. Question? I mix at 35 to 1 using 93oct fuel for my DLE 30cc and SPE 43cc. The instructions on the Sthil bottle recommend 50 to 1 and that is what I run in my chain saw which is as you know chain saws run under high load and high rev with not much air movement, and I have never had an issue when operating it. Thinking of going to 50 to 1 on the birds. Your opinion on doing this. (Others may chime in too)

I run 50:1 synthetic right from the start. What would generally take around 5 gallons of ass-less, I mean ashless oil to break in, take 7.5 to 10 gallons on synthetic.

Im a very firm believer in break them in on how you are going to fly them. I do have 1 rule that I follow. That is no hovering and torque rolling for the first 5 gallons, regardless of what fuel.
My EME 120 has seen 50:1 since the first drop of fuel. Approx 25 gallons of fuel. I also do run 93 octane in my higher compression engines. I have ran 87 and 89 in my 3Ws, and never noticed anything odd with them. I let fuel in my can sit all winter long. Fuel up the airplane with it the next year and go play!

So, yeah. You are gonna be fine with 50:1 on your DLE. If ever in doubt, revert back to engine manufacture recommendations.

 

[combat chicken]

I run 50:1 synthetic right from the start. What would generally take around 5 gallons of ass-less, I mean ashless oil to break in, take 7.5 to 10 gallons on synthetic.

Im a very firm believer in break them in on how you are going to fly them. I do have 1 rule that I follow. That is no hovering and torque rolling for the first 5 gallons, regardless of what fuel.
My EME 120 has seen 50:1 since the first drop of fuel. Approx 25 gallons of fuel. I also do run 93 octane in my higher compression engines. I have ran 87 and 89 in my 3Ws, and never noticed anything odd with them. I let fuel in my can sit all winter long. Fuel up the airplane with it the next year and go play!

So, yeah. You are gonna be fine with 50:1 on your DLE. If ever in doubt, revert back to engine manufacture recommendations.

Thanks. I do pretty much the same on break ln. For me a lot of circle flying for the first couple gallons.

 

[ericb]

I run 50:1 synthetic right from the start. What would generally take around 5 gallons of ass-less, I mean ashless oil to break in, take 7.5 to 10 gallons on synthetic.

Im a very firm believer in break them in on how you are going to fly them. I do have 1 rule that I follow. That is no hovering and torque rolling for the first 5 gallons, regardless of what fuel.
My EME 120 has seen 50:1 since the first drop of fuel. Approx 25 gallons of fuel. I also do run 93 octane in my higher compression engines. I have ran 87 and 89 in my 3Ws, and never noticed anything odd with them. I let fuel in my can sit all winter long. Fuel up the airplane with it the next year and go play!

So, yeah. You are gonna be fine with 50:1 on your DLE. If ever in doubt, revert back to engine manufacture recommendations.

That is how I do it also. No special break in oil is needed. Put in what your going to fly and go have fun. It will take a bit longer to break in.

 

[Bunky.F.Knuckle]

Thanks. I do pretty much the same on break ln. For me a lot of circle flying for the first couple gallons.

You got it, man.

 

[49dimes]

Like every one is saying 50:1 new engine is just fine as long as you don't let friction work too hard. For those of us who have a "heavy" throttle stick let it stay down like it wants to then! When I first ran 3dub I went through the "school" process @50:1 and seized cylinders because I stayed at wot long before I had any real time on the engine. What was that word again!?.... Uhm.... dog pooped and I was watching @stangflyer vid .....Oh! Yeah!.....Patience!

Now the really tricky question. Even though 32:1 for break in, on a new 3 dub, does this really help shorten the break in process? I say no. I think it is more the metallurgy and machining tolerances used and practiced by the individual manufactory as to why they recommend what oil ratios and when.

 

[stangflyer]

Did you know 3W recommends running an ashless oil (32:1) for 3 or 4 hours before going to 50:1 synthetic?

Well....No Joey, I did not know that....Tell me more!....

Ok Timmy; I will tell you more young fella!

Friction can be our enemy and our friend! Did you know that Timmy!?

No Joey!! Wow!! How can it be both? I'm confused??

Well Timmy....When an engine is new it has the basic tolerance required to allow "friction" to be our friend by honing and lapping metal surfaces so that they "mate" with each other!

MATE with each other!?!? You mean like how I want to do with my girl friend???

Well.....NO Timmy! Not in that way little fella! haha .

I mean to conform with each other and NOT spooning! This will reduce friction and allow "less oil" to do the same work as "more oil" as when the engine was brand new!

Focus Timmy!

All this talk of "mating" and "spooning" and "friction" and "lubricaton"! Wow.... I need a girlfriend. LOL

 

[stangflyer]

I was watching @stangflyer vid .....Oh! Yeah!.....Patience!

Are you saying I am not patient? I am just exuberantly careful. LOL