A while back I tried using E85 in an old chainsaw, I blew the rod almost instantly, I assumed this was due to the alcohol needing more lube oil mixed in the fuel - well - Sorta, but not the root of the problem.
I got tired of arguing with a stubborn chainsaw today and took a break and did a simple E85 fuel experiment. On my other attempt to run E85 in a chainsaw I mixed the fuel/oil in a normal red opaque plastic 1 gallon fuel jug, today I used a clear 2-liter soda bottle, much to my horror the oil started to settle out of the E85 almost instantly, within 5 minutes almost all the oil had settled out.
This test uses 4 oz of new Walmart blue 2-cycle oil, the 4 ounces equates to a 16-to-1 fuel/oil blend, this is a lot more oil than newer saws require but my old saws run fine on it and it adds some margin of safety for lubrication, but only if the oil stays blended.
I repeated this test using 4 oz of clean used veg and the oil has not settled out at all but it has only been a few hours. Model airplane fuel is basically methanol and veg oil (caster oil, lubes rather than burns due to it's high ignition temp) so I don't expect this eth/veg blend to separate, I will give it a try in the saw and see if it survives. Using soy oil in the blend may cause a bit more spark plug fowling but maybe not?
I had done some blend tests with E85 and used engine oil, the oil settled out of those too, I should have realized it would also happen with petro-based 2-cycle oil.
That's not the only problem with ethanol blends, if the fuel gets moisture in it which is more likely because of the ethanol, the ethanol water mix separates from the hydrocarbons.
Most model airplane fuels use synthetic oil. Castor oil hasn't been popular since the 1960's or so. The synthetics don't leave the deposits that Castor oil did. Note also that the Castor oil used in fuel isn't the same as the castor oil sold in drugstores. Some motorcycle shops still sell castor oil, preferred by some old 2-stroke customers.
The oils that ARE used in model fuel may not be the same as Walmart Blue 2-stroke oil. It might be worth researching it more.
I've read in other threads that E85 (and even straight ethanol mixed with gasoline) will drop it's lubricant load when the ethanol absorbs enough water. If true, then the trick is to keep the fuel "dry" in storage and use. Alternatively, a lubricant is needed that stays in solution even if "wet". Perhaps that's what model airplane fuel uses?
Does biodiesel provide enough lubricity for a 2-stroke? It may not separate out as readily.
'05 CRD B100
'01 TDi B100
Biodiesel as 2-stroke lube -
Doing a bit more reading about this, looks like it can. The best modern 2-stroke lube oils seem to be "ester based" synthetic 2-stroke oils, this appears to be basically BIODIESEL with additives.
This "jOURNEY TO fOREVER" web page has testimonials saying a 20-to-1 mix of biodisel and gasoline has worked well in 2-strokes. Click on the BLUE subject of "biodiesel in gasoline engines".
I have a half gallon sample of E85 that has a 25-to-1 mix of Paulen PRO Synthetic 2-stroke oil that has stayed mixed now for over a month, still have to try running it in the old weedwacker test engine. Commercial biodiesel is not available locally so I guess I need to make up a "Dr. Pepper" batch and give it a try.
There is a good bit of interest in this on many websites about outboard engines.
THIS links to a good article concerning burning alcohol with ester oils in older outboard engines. Biodiesel could likely replace the expensive ester oil by adding it at a higher ratio. Reading other web info concerning folks testing this they are running ratios from 4-to-1 up to 20-to-1 fuel (gas or alcohol) to biodiesel.
Another similer discussion with web links is HERE.
This is an old thread, but I thought I'd add to it. There are some companies that make 2-stroke oil specifically for alcohol or that is rated for use with alcohol
Glad to see that at least a couple manufacturers are now selling 2-stroke alcohol premix oil.
Looking over the Redline web site I did not find much info on it except a small paragraph in there "Synthetic Two-Cycle Lubricants" PDF tech paper. It says it can be mixed much LEANER than normal due to the engine burning more alcohol than gasoline? I would caution against this as my experience blowing a rod seems to support the need for MORE lubrication when burning alcohol. There price of $72.00 per gallon also seems a BIT steep, may be ok when burning it as the lube in small model aircraft engines as they state but a bit costly for bigger engines.
The Klotz web page seems more realistic, they call foe a MUCH richer mix for alcohol, even as high as 18% for model airplane engines, and a 16 to 20-to-1 mix for larger engines, MUCH safer place to start anyway. They do show SOME tech data and state that there oil is a blend of 20% Castor oil with "pure synthetic bases"?. Amazon.com shows the price for a gallon at $46.00, better, but still high and FAR higher than any basic biodiesel.
Still hoping to get around to testing some rich blends of biodiesel and E85. From web reading, several folks have run 10-to-1 successfully so I will start there and lean things out til something obvious shows up.
The 25-to-1 mix of the fairly cheap Paulen synthetic oil mixed with E85 (that I mentioned above) is still totally blended but I have not tried running it in anything yet, not brave enough to try it in anything I actually use and still have not gotten around to getting an old weed trimmer engine running to test it in.
Did you increase the jet size of the carburettor to compensate for the lower energy content of E85? Otherwise your engine might as well have blown up because of too lean a mixture.
That's what Redline means by lower percentage of oil: With more mixture goes through the carburettor, you also get more oil through. If you increase the jets by 25-33%, you can decrease the percentage of oil by 25-33% accordingly.
|Powered by Social Strata|