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Ethanol Or Methanol? best for Mix? reasons why or why not?

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Old 01-21-2011, 05:14 AM
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1ofmyfuns
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Default Ethanol Or Methanol? best for Mix? reasons why or why not?

I'm wanting to mix my own Nitro Fuel so I have been doinga little research on the subject, I came across this info. I have listed below and am wonderingif anyone else has any experience with using the ethanol vs methanol in the mix, my intent is just to be making up a basic 20% Nitro blend for my RC 1/8 buggy with a SH.21 engine.

I know there are probably a gilliondifferingopinions on this subject and I may very well be asking questions that have already been answered here and if so I appologize for that, but I'm just looking for the best bang for my buck and the included article I've listed here claims that the ethanol produces more energy that the methanol so Iam wondering if it will perform better in these little engines or is it a non factor with them and just an extra unneeded expense.

Thanks in advance to all who comment!

Article:
Now, as for the question, which is a better fuel, ethanol or methanol, ethanol is clearly the better fuel: it has 38% more available energy (86,000 BTU's per gallon for ethanol, while methanol only has 62,000 BTU's/gallon). Methanol is commonly used for racing as it is a cheap and easily available byproduct of the Natural Gas industry, and is cheaper than ethanol because they don't have to pay the distillation taxes. Ethanol is also used in racing, and the Indie 500 has used this fuel for over 80 years, now. Ethanol is less corrosive than methanol, and burns very clean, with only CO2 and water as the main byproducts of combustion (there is a slight amount of aldyhides in the exhaust, but it is 300% cleaner than burning gasoline.
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Old 01-21-2011, 06:19 AM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

While ethanol would appear to be the better fuel from its energy/pound you get more power from methanol because of the large difference in air/fuel ratio. Basically this means you have to burn more methanol which then more than makes up for the lower energy content. Ethanol would give about 90% the power of methanol (and methanol is cheaper anyway ).
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Old 01-21-2011, 06:20 AM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

They use methanol for racing because it has higher performance.  You burn methanol much richer and the total fuel mass is much larger and thus  has more heat despite the fact the BTU per unit mass is less.  It is also much cheaper.  No need to reinvent the wheel, use methanol.
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Old 01-21-2011, 06:29 AM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

Thank you very much Guys, you answered my questions very well on this, I have been around racing much of my life so Iknew that Methanol was the best choice for 4 strokes but was just wondering if there were an advantages at all to using it in these little Nitro 2 smokers.

Below is a formula I came across for mixing Home brew fuel and I'm wondering if these are correct measurements, I figured you Pro's here would know if they were or not.

Thanks, SahnG.

RC Nitro Fuel Mixing Chart
20% Nitro Mix
Formula for 1 gallon of fuel

20%/12% nitro/oil
nitro - 25.6oz
oil - 15.4oz
methanol - 87oz
_____________________________________
30% Nitro Mix


Formula for one gallon of fuel
30%/12% nitro/oil
nitro - 38.4oz
oil - 15.4oz
methanol - 74.2oz
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Old 01-21-2011, 07:10 AM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

Also the article has a couple of errors.  They just started racing with ethanol in the past few years, and metnol is also a clean fuel, except maybe more CO2.
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Old 01-21-2011, 09:32 AM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

Yes, the formulas are correct. Just multiply the percentage as a decimal (20% = .20) times 128 to get the ounces. Example: 128 X .20 = 25.6. I'll bet that there are websites out there with home brew calculators. I don't have a link, but maybe another someone else can post one.
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Old 01-21-2011, 07:55 PM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

Hello,
I don't mean to bother you but I was wanting to know if this formula would also work on Rc aircraft? I'm sure its a good formula for the cars and trucks because you posted it but I'm more concerned about finding a good one for my nitro aircraft! Also, what type of oils are you using and what are there flash points? If you could answer these questions for me I'd greatly appreciate it! I work in a oil and fuel warehouse so I have access to any and all oils and can get any type of fuel as long as my pocket book can handle the price! Anyways thanks for all your help in this and I hope to hear back!
Thanks,
Clint~
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Old 01-21-2011, 11:23 PM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

For RC plane engines a safe amount of oil is 20% and the safest type of oil is castor. Synthetics (of the type that will mix with methanol) have a flash point of around 425F but at those temperatures they'll also almost immediately revert to the chemicals they were made from leaving nothing for lubrication. Castor has a flash point of around 450F but at those temps it's starting to turn into another lubricant to keep the engine safer.

Flash point though is just the temperature at which any oil that's vaporised on the surface of an oil film can ignite from an outside source like combustion leaving the still remaining liquid oil to lubricate. The other temp related issue is fire point which is the temp that any liquid oil will auto-ignite. For synthetics this is a little above the flash point (425+) but for castor it's somewhere above 800F.

As far as mixing fuel goes, you really should try using metrics. In the 20/12 blend below this would simply mean measuring out 200cc of nitro, 120cc of oil and top up to a litre with methanol. No calculator needed, just do it in your head .
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Old 01-22-2011, 06:43 AM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

What about an anti-foaming agent ? If the tank is well isolated, it anti-foaming agent even needed ?
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Old 01-22-2011, 03:56 PM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

The old standby for anti foaming is a quick squirt of ArmorAll into a gallon of fuel but I believe they've changed the formula now and it doesn't have silicone in it any more. The old stuff certainly works but I doubt it's really necessary.
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Old 01-29-2011, 08:29 PM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

i have been mixing my own nitro . DONT DO IT there is NO advantage. you cant mix 8 oz of methanol and 8oz of nitro and get 50%/50%. you HAVE to use a hydrometer. and it is NOT easy. you will be better off buying over counter premixed nitro. i just spent 6 hours trying to sort out 70%.
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Old 01-30-2011, 04:20 PM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

Moe, you keep repeating this but mixing fuel is dead easy and doesn't have to be turned into rocket science. The accepted (traditional) method is to mix by volume in which case 8 (fluid) ounces of both methanol and nitro gives a 50/50% blend. If you mix by mass then 8 ounces of each will give a 50/50% blend by mass but the volume% will be something like 60/40 because of the different densities (methanol .796 and nitro 1.13).

Using a hydrometer is simply mixing by mass with the added complication that you have to know the coefficients of expansion and the temperatures of both ingredients. If you've been using a hydrometer then what you think is 70% nitro is likely to be more like what everyone else would consider to be 50% (by volume).
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Old 01-31-2011, 05:57 AM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

He is thinking of drag racing where the percentages is by weight and the hydormeter is used to check that there is no cheating when nitro percentage is limited. Not so with models. You simply mix by volume.
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Old 01-31-2011, 07:06 AM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

You forget one point on glow engines. They run because the catalytic reaction between the methanol and the platinum element in the glow plug; that keeps the plug going. The battery is there to get everything started but it can be removed because of this. If you want to put an ignition system on, the spark and ethanol would work good. I dont know if the oil will mix though.
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Old 01-31-2011, 09:11 AM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

Hey Moe: I'm curious. What type of fuel are you mixing that requires the use of a hydrometer? A specialty fuel for R/C contest use perhaps? I agree with Downunder and Sport Pilot; to mix your own fuel for general R/C sport use all you need is a measuring cup (or 1 liter graduated cylinder) to measure the methanol, nitro, and oil. As a great fuel mixer once said, its "dead simple". The percentages of oil and nitro in virtually all commercial R/C glow fuels are by volume, not weght. The one exception may be Byrons fuel.
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Old 01-31-2011, 03:06 PM
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Default RE: Ethanol Or Methanol? best for Mix? reasons why or why not?

Quote:
ORIGINAL: Sport_Pilot
He is thinking of drag racing where the percentages is by weight and the hydormeter is used to check that there is no cheating when nitro percentage is limited.
I can understand the use of a hydrometer in drag racing where I believe the nitro has to be diluted with a minimum amount of methanol (and there's no oil in the mix to confuse the issue ) but this is a forum for model engines where that kind of restriction simply doesn't apply. The nearest thing to it in world or national contests for models is the couple of events where a certain fuel is specified and in those cases the fuel is supplied by the organisers who, of course, mix by volume.
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