"Smoked" glow engines
12-29-2011, 06:36 PM
#26
RE: RE:
ORIGINAL: blw
Clarence Lee must have had more than one article because I recently read one where he was recapping previous information. He did have the calculations and I'll go back and try to find them. He said the same things the MAN article did. All was very interesting.
ORIGINAL: earlwb
So you might have 20% to 25% or more oil in the fuel for a small engine whereas in a big 30cc or larger glow engine you only needed 10% to 12% and even 8% may work OK in some cases. I think he had worked out the optimum oil percentages needed by engine displacement too.
Dave Gierke and Clarence Lee pretty much agreed with it as well as they used to quote his article as a reference in their articles too.
So you might have 20% to 25% or more oil in the fuel for a small engine whereas in a big 30cc or larger glow engine you only needed 10% to 12% and even 8% may work OK in some cases. I think he had worked out the optimum oil percentages needed by engine displacement too.
Dave Gierke and Clarence Lee pretty much agreed with it as well as they used to quote his article as a reference in their articles too.
The MAN article that Dave did, as mentioned above with a link has the engine oil percentage formulas detailed in it too.
12-31-2011, 07:43 AM
#27
RE:
I still think a twenty-fold difference is oil requirement (100:1 versus 20%) is very significant and amazes me. ED...interesting article....seems to support that there is a lot of over-oiling in modern fuels...which may go along with a inflated fear of lean runs(or maybe not)
The 100 to 1 ratio is only for the larger gas engines with ball or roller bearings throughout and only after well broken in. Even then some say you should not go past 50 to 1.
12-31-2011, 08:14 AM
#28
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I've been running my 23CC predator gas heli on 100:1 amsoil and coleman camp fuel for years trouble free, as have many. I even stick a boroscope in on a regular basis and the engine looks new inside. Like you say it IS a roller bearing engine...but its not huge.
Honestly, This is about what I figured I'd get from this thread . Definitly not trying to Bust B@lls or anything, But we have a bunch of "some say" , "have been know to" yadda yadda...but the intention of my post was to see if anyone had any pictures or had done any tachometer research,etc. Plenty of pics of crashed planes for the curious, but not many of burnt up engines. You won't find one person who will tell you its a GOOD thing to do. Again, don't take this the wrong way I'm just a bit skeptical that a modern engine with castor in the lube would be all that easy to damage with what I consider fairly low temps. Not trying to disprove anyone, just really interested for my own knowledge in seeing what kind of margin there is? Looks like the only way to get a answer is to do some research on my own with a unwanted engine and take some tach and temp readings and repeatedly run it lean to the point of quitting...like peak it then 1 click in every 5-10 seconds till it stops.
Honestly, This is about what I figured I'd get from this thread . Definitly not trying to Bust B@lls or anything, But we have a bunch of "some say" , "have been know to" yadda yadda...but the intention of my post was to see if anyone had any pictures or had done any tachometer research,etc. Plenty of pics of crashed planes for the curious, but not many of burnt up engines. You won't find one person who will tell you its a GOOD thing to do. Again, don't take this the wrong way I'm just a bit skeptical that a modern engine with castor in the lube would be all that easy to damage with what I consider fairly low temps. Not trying to disprove anyone, just really interested for my own knowledge in seeing what kind of margin there is? Looks like the only way to get a answer is to do some research on my own with a unwanted engine and take some tach and temp readings and repeatedly run it lean to the point of quitting...like peak it then 1 click in every 5-10 seconds till it stops.
12-31-2011, 09:01 AM
#29
RE: RE:
ORIGINAL: Sport_Pilot
The 100 to 1 ratio is only for the larger gas engines with ball or roller bearings throughout and only after well broken in. Even then some say you should not go past 50 to 1.
I still think a twenty-fold difference is oil requirement (100:1 versus 20%) is very significant and amazes me. ED...interesting article....seems to support that there is a lot of over-oiling in modern fuels...which may go along with a inflated fear of lean runs(or maybe not)
The 100 to 1 ratio is only for the larger gas engines with ball or roller bearings throughout and only after well broken in. Even then some say you should not go past 50 to 1.
12-31-2011, 11:01 AM
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I'm absolutely not discounting the value of the knowledge or comments, I appreciate them all! Its simply that what I'm looking for are detailed specific accounts or photos, to satisfy my curiousity. I thank all for their input! My scope won't fit through a glow plug hole...But I'm sure I can get some pics with the head off and through the exhaust port when I decide to do the testing. Thanks again!
12-31-2011, 03:50 PM
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RE: RE:
When the UCON synth first came out, I wasted a new Series 71(??) Torp .35. The P/L became scrap before it was broken in. That was a lapped iron/steel P/L though. The crank survived fine, but that was on ball bearings.
12-31-2011, 06:13 PM
#35
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RE: RE:
I think a lot of us scrapped an engine or two before we figured out that the lapped piston/iron sleeve engines preferred castor oil.
My wife's OS Max .35S R/C used to smoke for a few minutes after we landed her Andrews A-Ray back in the late sixties. We were burning K&B 500 fuel. I figured if they sold it as model fuel and it came from a notable fuel maker, it had to be good. Anyway, the OS actually survived the abuse and provided a few years of service before we got tired of it and moved up to ball bearing forties.
Ed, NM2K
My wife's OS Max .35S R/C used to smoke for a few minutes after we landed her Andrews A-Ray back in the late sixties. We were burning K&B 500 fuel. I figured if they sold it as model fuel and it came from a notable fuel maker, it had to be good. Anyway, the OS actually survived the abuse and provided a few years of service before we got tired of it and moved up to ball bearing forties.
Ed, NM2K
