Lifer

My Feedback: (1)

I run a quality synthetic at 40-to-1 and have no issues with my engines. I have friends that run 100-to-1 and claim the engine produces more power. If that is true, just how much more power can reasonably be generated by running that percentage?

I mean, realistically, is a couple of hundred rpm's really worth it? The oil difference is about 1.28 ounces versus about 3 ounces. Oil is cheap when you consider all the other costs associated with our hobby. Why not run the engine with a little more oil? Heck, compared to the 20% I run in my glow engines, this is a minor point.

Just asking for the input from one of the experts like T.O.M. or Jody.

JoeAirPort

My Feedback: (41)

Stihl Ultra HP in white bottles has been replaced by Stihl Ultra in grey bottles. Same thing different packaging.

jharkin

My Feedback: (2)

To add to the controversy.... I fly at a field shared with an ultralight club. From what Ive seen, none of those guys run less than 50:1 oil. And 'ol fashioned mineral oils like Penzoil seem to be quite popular.

If its good enough when your life can depend on it, its good enough for me.

Penzoil 32:1. Simple. cheap. Goes in everything including the weed wacker and the chainsaw....

Tired Old Man

My Feedback: (1)

If less oil equals more power just imagine how much more power you could obtain using no oil........

Moki 1.8

My Feedback: (11)

Should I run a few gallons with the stihl mineral oil and then switch over to the ultra synthetic?

Eagleburger

I use the local dino oil at 29:1. Its cheap, I am cheap so it suits me great. It must have a good dose of detergent in it. I replaced a muffler on a DL-50 after ~15gal and it was spotless inside except for a 5 o'clock shadow on top of the piston that could be rubbed off with a cotton bud.

At that point, had I been using redline or sthil at 40:1, I would have had to pay an extra $85 for the privilege. Incidentally, $85 is a 1/4 of the new price of the engine.

The engine has since burned another 25gal and shows no sign of quitting anytime soon.

On my DA-100 I save $1 per flight, 1200 flights I save enough to pay for a new motor.

The price you pay may be different so do your own calculatiions

w8ye

My Feedback: (16)

Sounds good to me

Moki 1.8

My Feedback: (11)

Yea ill probly run it for a while being that I bought 6 bottles of it lol. I ran my dle-30 with it yesterday and it did fine, mixed at 4oz of oil to one gallon of gas. Once I use it all im gonna switch over to the ultra synthetic

Tired Old Man

My Feedback: (1)

Why change? Almost all the air cooled oils work just fine if you use enough of them. The mineral Stihl is no different. It's a good oil. Eagleburger has it together.

JoeAirPort

My Feedback: (41)

Lol

Lifer

My Feedback: (1)

I still would be interested in how much power they may be gaining running 100-to-one mixtures.

Ed

If I were to switch now from a 100:1 oil ratio to a 40:1 ratio, in which direction could I expect to have to retune my engines ? Leaner, or richer ?

Ed

Tired Old Man

My Feedback: (1)

Leaner normally, but that depends on where it was at before.

Regarding a gain in rpm with less oil. Doesn't happen that way. The best power would be made with a cold engine since that would be the best ring seal. Lean ratio engines have proven to much more tuning tempermental that denser oil engines. Some big money flyers found that out at contests. Changing oils and ratios to more oil from less provided them better tuning consistency and more power. If we had larger engines with more inner surface and fin area we might benefit, or at least make the most of lean oil ratios but that is not the case. Oil is not just about lubrication. It seves several other very important functions as well. Short any one or combination of them and the engine suffers.

For some interesting reading people might want to do a search about service intervals with ultralight engines. Those running lean ratio Amsoil have to service their engines more frequently. However, those that that want to use the stuff should feel free to do so. The bottom line is the engine belongs to them and they can do whatever they want, as it should be.

JoeAirPort

My Feedback: (41)

It depends if you're talking petro or syntho. In general the 100:1 syntho to 40:1 syntho would need them richened. With less gas and more oil in the mixture, you need to compensate by adding more gas to the fuel:air mixture using the needles. Just do a retune either direction you go and it'll be fine. Changing oils and not re-tuning is a recipe for disaster. Especially in the case you're asking about (siezed engine because it would run lean). 100:1 to 40:1 is a huge change in oil:gas mixture.

PS: The above assumes it was tuned perfectly to begin with.

Ed

TOM says leaner .................... Joe AP says richer ????????????? I'm using synthetic Amsoil at 100:1, and going to synthetic Red Line at 40:1.

Which way can I expect to adjust my Carbs guys ?

Ed

w8ye

My Feedback: (16)

If you know your stuff, you will tune the engine to run correctly

Tired Old Man

My Feedback: (1)

I could have been wrong since I never pay attention to which way the needles go when I re-tune. A little this way, then a little that. Unless I have a CO meter I go by ear. I just make the engine run right, which is what anyone should do

JoeAirPort

My Feedback: (41)

I agree with both of you. Quoted from my last post "Just do a retune either direction you go and it'll be fine.".

rc bugman

My Feedback: (30)

Hi,

If the oil burns as is the case with Pennzoil aircooled, the engine is tuned with needle valves more closed than mixtures which burn only (or mostly) gasoline. From some testing I conducted a few years ago, needles had to be opened when Amsoil 100:1 and non-burning synthetic oils like Belray 1HR were used compared to Pennzoil air cooled.

Hope this helps

Elson

Ed

Thank you Elson, it helped totally. It was a lot more definitive answer.

Thanks > Ed

ka9fax

My Feedback: (9)

Hi T.O.M.
1st, thank you for all your knowledge that you share with all of us. I follow your forums and thanks to you and Jody I have made fine choice's. Im useing Stihl Ultra 50 to1 in a DA50R. only 2.5 gallons so far. If it was you, would u also go up to 40 to 1 with the Stihl Ultra in my DA?
Also 1 last ques. I did not do any break in, went right with this mix. please let me know if u think i did worng so i do not keep making the same mistake on future engines.
thanks,
ka9fax

Tired Old Man

My Feedback: (1)

I use one oil and ratio for break in and runnng. The only difference is how the engine is run. The more oil you ue the longer the break in. However, more oil removes break in wear particulates faster and more completely than less oil. This is one of those personal choice areas, like so many others.

Based on what I've seen I would run a DA on a 40-1 mix. It's not so important with a lightly loaded engine but is with a heavily loaded one. RC does not load an engine heavily, but their are long term benefits of a little more oil. Less piston scuffing being one of them.

captinjohn

<hr />The reason is simple why the needles had to be opened. That extra gas brings with it extra oil to lube the engine correctly.With amix of oil at 100-1, any kind of lean-out, that engine is going to be in trouble. Capt,n

rc bugman

My Feedback: (30)

Hi,

I think that the needles need to opened more with non burning oils because when oil burns it contributes to the power of the engine. Without the burning oil component, more gasoline is required to achieve the same engine power. In my tests run a few years ago, fuel consumption increased by about 15% with amsoil at 100:1 and Belray 1HR at 50:1. For most RC applications, extra fuel consumption is not a problem. For some of us, the extra 15% fuel load is an issue and we stay with oil which contributes to engine power by burning.

Elson

ka9fax

My Feedback: (9)

Thank You T.O.M. Will do.