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Engine basics => Engine set up tips => Topic started by: frank mccune on November 17, 2018, 05:35:36 PM
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Hello:
Has anybody used poly
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Hello:
Has anybody used poly
"Poly"?
I have used PO in the usual low amounts, and on rare occasions for experiments, acetone. Nothing useful was found for stunt applications, as far as I am concerned.
The acetone was intended to dissolve the clear gelatinous blobs that were found floating in some fuel we had at the 1995 NATs. Dissolved the blobs, sort of, and had no other detectable effects. And the fuel ran almost how it had before.
Brett
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I believe that acetone is used with FAI fuel for cold weather flying. That and wrapping your cylinder with aluminum foil holds the heat in for consistent runs.
Dennis
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FAI speed uses only 20%caster and 80% Alky
prop was used in speed and racing to help light of 75 % nitro instead of Alky.a little acetone will dissolve small amounts of water in the fuel.
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Hello:
Has anybody used poly
Those two are VERY different chemicals, PO will increase power, it is very dangerous to be around, and evaporate really fast
The only use I have found for acetone in the fuel, is it will extend the run time a few laps if your critically short on time, I would not use more than 1 ounce in a gallon
Randy
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Those two are VERY different chemicals, PO will increase power, it is very dangerous to be around, and evaporate really fast
The only use I have found for acetone in the fuel, is it will extend the run time a few laps if your critically short on time, I would not use more than 1 ounce in a gallon
A small amount of acetone was able to dissolve the clear globs that were floating around in the bad batches of SIG fuel at the 1995 NATs. I want to say I tried about an ounce in a half-gallon of fuel. Shook it up, no more globs, and even weeks later, it stayed that way. It still ran poorly, so I gave it to some RC guys and it ran bad for them, too.
It didn't do much if anything to the white flakes I got from Red Max castor oil. If anything, it made even more flakes.
Brett
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A small amount of acetone was able to dissolve the clear globs that were floating around in the bad batches of SIG fuel at the 1995 NATs. I want to say I tried about an ounce in a half-gallon of fuel. Shook it up, no more globs, and even weeks later, it stayed that way. It still ran poorly, so I gave it to some RC guys and it ran bad for them, too.
It didn't do much if anything to the white flakes I got from Red Max castor oil. If anything, it made even more flakes.
Brett
Yep. that is why I said only useful thing... and those white flecks/flakes are really hard to get rid of, The chemical additive Lubricin that SIG and many others sold was very bad about flecking the castor in fuel, especially when it was cold
and they can and did stop up spraybars
Randy
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I believe that acetone is used with FAI fuel for cold weather flying.
In America, FAI fuel just means any fuel that has zero nitro, regardless of the type or quantity of oil used. Acetone up to about 3% is said to aid starting and give smoother idling similar to around 5% nitro. Shell A Racing fuel comes with 3% acetone and can only be bought in their own 20 litre drums but for decades was the only easily available methanol in Australia. Apparently Shell used the acetone because it reduces the hygroscopic property of Methanol.
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Coleman lantern fuel would be more beneficial for stunt or sport flying, IMO. Something like 1% > 3% will improve the fuel economy (I'm not a fan, but sometimes there's a need) and starting.
Ronson lighter fluid is handy for starting, but it's just a handy dispenser full of naphtha, which you can buy cheaper at the hardware or paint store. It's very volatile, so it wouldn't make sense to mix it in the fuel, IMO.
In George Aldrich's excellent article in AeroModeller Annual back in the '60's (can't say what year, as I don't have that year), he said to never use propylene oxide in fuel with alcohol. He didn't say why, as I recall, but it will tend to give pre-ignition. I actually did use PO with alcohol, but used a fair amount of Nitro Benzine (4%-8%) with it, or later, Amyl Acetate in much smaller (1%) percentages. George's information didn't help me, but eventually explained why what I was doing worked. When the nitro content gets very high, it's difficult to get it to light up and run. With 75%-80% nitro and 20%-25% oil, it just won't start with an appropriately cold glowplug. Maybe with an inappropriate 4-cycle glowplug? D>K Steve
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Coleman lantern fuel would be more beneficial for stunt or sport flying, IMO. Something like 1% > 3% will improve the fuel economy (I'm not a fan, but sometimes there's a need) and starting.
Agreed, that's probably better in theory than acetone. But you might actually have acetone with you (for cleaning lines) in those rare cases you need it, whereas you probably won't have lantern fuel and probably don't want to carry it around with you on the off chance you need to get another 10-15 seconds.
Note that lacquer thinner ALSO adds a bit of time, and I have used it for that purpose, because, again, that's what I had at the time.
Brett
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Perhaps not of interest to glo flyers. I have experimented with spark ignition fuel. I have used Coleman lantern and SAE 70 motor oil. Oil makes a mess all over the plane. So I wanted to use castor oil. Castor would not mix with Coleman, so I added about 4 tablespoons acetone to a quart of Coleman/castor mix. It solved the mix problem, and the castor oil exhaust doesn't seem to stick to the plane so much.
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In George Aldrich's excellent article in AeroModeller Annual back in the '60's (can't say what year, as I don't have that year), he said to never use propylene oxide in fuel with alcohol. He didn't say why, as I recall, but it will tend to give pre-ignition. I actually did use PO with alcohol, but used a fair amount of Nitro Benzine (4%-8%) with it, or later, Amyl Acetate in much smaller (1%) percentages. George's information didn't help me, but eventually explained why what I was doing worked. When the nitro content gets very high, it's difficult to get it to light up and run. With 75%-80% nitro and 20%-25% oil, it just won't start with an appropriately cold glowplug. Maybe with an inappropriate 4-cycle glowplug? D>K Steve
George Aldrich wrote a comprehensive piece on engines in the 68-69 Aeromodeller Annual. The title of the article is "Secrets of Engine Performance". He gives various formulae of fuels for various purposes and showed a "Fuel Ingredient Glossary". He uses Propelene Oxide in various mixtures. In the Glossay, he explains the Propelene Oxide (P.O.) is "an igniter used to 'set off' Nitro Methane and it is not to be used with methanol". He does not elaborate any more on the use of P.O.
(BTW, I have all issues of the Aeromodeller Annual from 1948 to 1978-79.)
Keith
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Coleman fuel (called Shellite in Australia) is a form of very pure petrol but only has an octane rating of 50-55 so wouldn't take kindly to too much ignition advance. However it's a mineral fuel while castor is vegetable based so can't mix together. Acetone is a cosolvent which allows them to mix. Same goes for diesel fuel where kerosene (mineral base) has castor but, happily, the necessary ether is also a cosolvent.
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We had some pulse jet fuel with many pollys and proolenes & di oxides in it , centuries ago .
It was good. If you left a set firbreglass resin set paint brush in it overnight , it was like new in the morning . LL~ S?P
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George Aldrich wrote a comprehensive piece on engines in the 68-69 Aeromodeller Annual. The title of the article is "Secrets of Engine Performance". He gives various formulae of fuels for various purposes and showed a "Fuel Ingredient Glossary". He uses Propelene Oxide in various mixtures. In the Glossay, he explains the Propelene Oxide (P.O.) is "an igniter used to 'set off' Nitro Methane and it is not to be used with methanol". He does not elaborate any more on the use of P.O.
(BTW, I have all issues of the Aeromodeller Annual from 1948 to 1978-79.)
Keith
Propylene oxide works very well or increasing power in methanol fuel, and YES it is used in methanol based fuel. It is an oxidizer and carries more oxygen into the engine, boosting horse power and torque. I have used 100s of gallons of fuel with P.O. in it, and by the way it is dangerous, a carcinogen irritates skin and eyes, can cause cancer. I used to keep it in glass gallon jugs, but no more
Randy