Hi there all respectable senior flyers,

Here I come again with another question in order to find the answers of that question.

The reason I started that thread and wanted to ask the question that here in my country, I dont know about many other people in other cities of my country what they use, but we here used a simple fuel which is a combination of Methanol and castor oil. Methanol is 80% and castor oil is 20%. It's 80 rupees per liter & 320 rupees/g. $ 1.3 per liter and $5.3 per galon. Some people say here that Nitro is nearly 3,500 rupees per liter which is $53.33 per liter and we don't know some people are selling it 100% nitro, and some people are selling mixture of nitro which is also expensive nearl 600 rupees per liter which is $10 per liter or $40 per galon.

My question is What is Nitro Fuel and why does it call Nitro is it generic name or is it short of its chemical formula name? Is it a form of Hydrocarbons (CH)? Is it different from methanol or is purified form of methanol? Is nitro fuel used 100% in the glowplug planes or is it mixed with some fuel? What are the pros & cons of using nitro fuel? and one thing my common sense says that Nitro cannot be used 100%. What are the good brands of nitro and normal fuel in USA and their minimum to maximum price range?

Your comments, advices and clarifications would be highly appreciated like always.

Thanks

Mody

I think i read off my Nitro Trucks fuel can that it contains Nitromethane, which its named after, but theres other stuff in it.

nitro refers to nitro methane,most european countries use what is called fai fuel just 75% methanol and 25% castor oil.nitro is used to provide for a better idle and can increase top end rpm's.I choose to use low nitro fuel and use a slightly larger engine as it keeps the flying cost down in the long run.when i was running ducted fans the difference between 25% nitro and 10% was only about 500 rpm not really worth the expense.I got more rpm by going to a larger carb and a pump.

The fuel mix you gave, 80% Methanol and 20% oil is often called FAI fuel and is used a lot I'm told in Europe. ANY mixture containing ANY nitro could be called Nitro fuel and it is therefore a very generic term.
A typical mix over here would be 65% methanol, 18% oil (castor or synthetic or combination), 15% nitro and 2% various additives such as anti-foamers, dyes, detergents, etc.

If the Nitro has been diluted before mixing that must be taken into account of course.

Thanks a lot shortymet55,aerowoof,bruce

for your replies, so basically Nitro or Nitromethane itself is a different chemical which is used as an additive in methanol+castor oil mixture in order to increase the RPM's and performance of the engine. I was also told that nitro reduces the life of the engine as it tends engine to run on high rpm's is it true?


Mody

There are engines run regularly on 15% nitro 15-20 years old and still going strong. I don't see any negative effect. Oil content is important though. Go with a minimum of 18% of some type of oil content for lubrication and don't run lean. If you have a high compression engine DESIGNED to run FAI (Federation Aeronautique Internationale) fuel it MIGHT effect the engine. They can have compression lowered by adding a shim gasket under the head.

You got it dead right there . Nitro is just an additive in glow fuel and isn't a necessary part of the fuel. The only thing that's necessary is the methanol because it's the only thing that keeps the glow plug glowing after the battery is disconnected. The next thing in fuel that's necessary is the oil which lets the engine keep on running . Once you've got both those things then anything else is just an accessory.

If there was no such thing as nitro then every engine would be made with a compression that suited just methanol (around 13:1). But nitro is cheap in America so they all use it (although lately I've seen a swing away from it) and because America is the largest market for engines then most companies have modified the engines to make them suitable to use nitro. This means they've had their compressions lowered to suit (down around 9 or 10:1). All engines will still run without nitro but not quite as well as they could do. Our loss . The difference though is fairly small so nothing to worry about.

The fuel you use is true FAI fuel (which is exactly what I use too) but any fuel without nitro is known generically as FAI fuel no matter how much oil or even if it's synthetic oil. Nitro doesn't really affect the life of an engine because they're not running all that much faster than an engine on zero nitro, they'll just use a heck of a lot more fuel over their lifetime than one without nitro .

More than that, in the States "nitro" is a marketing term. It's how the marketeers go after the professional wrestling segment of the population. It's getting so that those of us that call it glow fuel are in the minority.

Agreed, and the prime example is going after the "kiddy" market for RC cars. Nitro sounds powerful where "glow" sounds......well, what's glow mean?

I found this artical it was intresting and explanes a little more what nitro does and is.

nitromethane is made of propane CH3NO2.
NITRO = POWER! But….there are conditions and contingencies. First of all, it doesn't add power because it's such a "hot" chemical. Not at all. This may come as a surprise, but the methanol (methyl alcohol) in the fuel is by far the most flammable ingredient….nearly twice as flammable as nitromethane. As a matter of fact, if nitro were only 4 degrees less flammable, it wouldn't even have to carry the red diamond "flammable" label!In actuality, nitromethane must be heated above 36 degrees Celcius before it will begin to emit enough vapors that they can be ignited by some sort of spark or flame!
suppose we were to find a way to run more liquid through our engines without increasing the air supply? That would add power, wouldn't it? Well, guess what….we can! An internal combustion engine can burn more than 2 ½ times as much nitromethane to a given volume of air than it can methanol.

Also (and this will come as a big surprise), the drag racing industry only consumes about 5% of all the nitromethane produced world-wide; and the hobby industry about another 2% or so. This means we have no "clout" whatever, and simply must pay the asking price. Where does the rest of it go? Industry. It's used for a variety of things - a solvent for certain plastics, insecticides,and I'm told it's an ingredient in Tagamet, a well-known prescription ulcer medication (no wonder that stuff is so expensive!). Please note that while nitromethane is an ingredient in making some explosives, under normal use, it in itself, is not exploseve.

Nitro is actually a very poor fuel because it's only got half the heat value of methanol, pound for pound (gram for gram, whatever). For nitro to give the same power as methanol you'd have to burn twice the mass of nitro. And this is exactly what happens.

All fuels have a certain air/fuel ratio where they burn best to give maximum power. For petrol this is about 12.5:1 (which is slightly richer than the ideal or stoichiometric ratio) and means that you need 12.5 pounds/grams/whatever units of air to burn 1 pound/gram/etc od petrol. This is the usual way of giving the ratio but for the moment we'll switch the ratio around to fuel/air because it's probably easier to see the differences. So the fuel/air ratio for petrol becomes .08:1 which means .08 pounds of petrol burns in 1 pound of air.

For methanol to burn and give maximum power the ratio is .18:1 so you can see that you need a little more than twice as much methanol than you would for petrol using the same amount of air.

Now nitro. This one is strange because it gives maximum power over a huge range of mixtures. The minimum ratio is .4:1 or just over twice as much as methanol. This is where nitro can just barely be better than methanol because it's only half as good a fuel as far as heat value goes. But nitro still works extremely well at a ratio of 2:1 which is near enough 10 times richer than methanol at .18:1. Is it any wonder that needling with nitro seems so much easier than with straight methanol? But the fuel consumption can be huge compared to running zero nitro fuel.

Naturally, when you have a mix of nitro and methanol then the ratio falls somewhere between the two extremes of .18 and 2 but the fact remains that extra power comes from increased fuel consumption. So you pay more for fuel that gets used up faster, kind of a double whammy on the hip pocket .

Thanks a lot for your informative replies downunder, mikeL, horace.

I did learn from it, yes, nitromethane is a hydrocarbon, and is used as fuel additive but I read its also called rocket propellent, as methanol is concerned which is ethyl alcohol its the real thing alongwith castor oil or synthetic oil. Related to it, though it seems to be little different question, but I wanna ask, when we talk about 2 stroke engine, it is cheap in price, gives more RPM than a 4 stroke. But when it comes to 4 stroke engine, it is said, the it sounds realistic, which it really does, also its expensive why its expensive Im still unable to figure it out, third thing its fuel efficient. Fuel efficient in what way? does it consume less fuel and give more flying time than 2 stroke engines? cos it completes it cycle in 2 stroke, where a complete combustion cycle in 2 stroke engine takes 1 stroke. I also heard that maintenance of 4 stroke engine is really difficult and once 4 stroke engine starts bothering you, its really pretty difficult to set them according to your desire, how much is it true.

Thanks in advance again

Mody