BaxterC

Hey SuperMaxx, Yes in those large supercharged motors, I agree, but in these little beasts, the nitro cools, and aids in the combustion when Idling, those large beasts have a timing system you can adjust and all. if you run 90% nitro in these little motors, you will get preignition and dettonation so bad you will more than likely throw the conrod through the crack case. in these little engines, the methanol makes the power and the nitro helps to a point.

BaxterC

Have you got oil on the clutch?

Pyramid

That pipe is perfect for technical track with no more than 55meter straight I believe. One think you must remember, the original manifold shape will hit your rear side pulley aluminum adaptor and it will be mounted below chassis. So you have to use such as Bosch heavy duty dryer to bent it outward to the top for both clearance with side pulley and the ground.

Funny think, the manifold is also mounted below the chassis on their own car kit, the G4..

SupermaxxRich

iTrader: (16)

I understand what your saying about the Nitro helping to cool, I agree. But even in RC Drag Racing, they run 40-50-60% Nitro, and they say it makes a huge difference in power. They know that running that high of nitro hurts there engines but they don't care because they want max power and the only way to get that is with increasing nitro. These guys run JP's, Rody Modifieds and other engines costing about $900 US! But that still isn't enough power for them so they ram lots of Nitro in there to make the power they want. If you have ever seen a cooling head on a drag race RC it looks really funny. Usually one or two fins. But the engines run cool enough between the nitro and the amount of run time they see.

Talk to you later....

BaxterC

This is very interresting, Supermaxx, please dont get angry as this is a great way to swop knowledge and it helps us all round.

The reason they have such small heat sinks is because they need to get the temp very high for the nitro. Nitro combusts at much higher temperatures than methanol, and generally burns slower, but I am sure that at high temperatures the nitro makes god power.

I didn't know the drag guys used a different fuel, i have not had any interest, so I never checked.

Have a look at this

I am sure you all will find this VERY interresting, it is to do with aeroplanes, but the baseline is the same. I am sure this will explain better than I can.

BaxterC

CAN YOU CHANGE THE AMOUNT OF NITRO
IN FUEL WITHOUT DAMAGING THE ENGINE?

Yes and no. Yes, you can change the percentage of nitro in your fuel safely, but you must not make a change and run the engine hard right away. Every engine undergoes a process called “hysteresis.” In hysteresis, the engine components slowly acclimate to the specific cylinder pressure and engine temperature that result from burning a particular type and blend of fuel. A change in fuel changes the whole picture for the engine. An engine that is accustomed to a certain amount of expansion using its usual fuel might now have to cope with increased cylinder pressures and the additional expansion caused by higher temperatures. Simply pouring a new fuel into the tank and “letting 'er rip” places undue stress on the engine components.

If you use a different blend of fuel, your engine has to go through a second “break-in.” Run the fuel mixture slightly rich and ease into the throttle for a few tanks before you nail it. If you fail to follow this procedure, your engine will still survive 99 percent of the time, but it will last longer and run stronger if you make a gradual change to a new fuel. There is also a break-in period during which using less nitro presents a new set of parameters for the engine.



Have a look at this

BaxterC

According to this article on the Powermaster fuels website

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Nitromethane…..everybody knows it's there, but few, it seems, really know much about it. Although most seem to know - at least vaguely - that's its primary purpose is to add power, we still get an occasional call or letter asking, "Why do you use it in model fuel?" At best, there is much misinformation regarding this somewhat exotic ingredient. Let's see what we can do to clear some of it up.

Nitromethane is just one of a family of chemicals called "nitroparaffins." Others are nitroethane and 1-nitropropane and 2-nitropropane. Nitroethane can be used successfully in small quantities. (Top fuel drag racers, which generally run on straight nitromethane, sometimes add a little in hot, humid weather to prevent detonation.) At one time, nitroethane was only about half as expensive as nitromethane, but its cost now is so nearly the same, using it to lower cost is hardly worth the trouble. Neither of the nitropropanes will work in model engine fuel. Incidentally, nitromethane is made of propane, in case you didn't know (and I'll bet you didn't).

Yes, 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 to most readers, 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 to 96 degrees F. before it will begin to emit enough vapors that they can be ignited by some sort of spark or flame! (I demonstrated this not long ago to a friend by repeatedly putting a flaming match out in a lidful of nitro. I might add that he insisted on standing about 20 feet away during the demonstration.)

So….how does it add power? We all know (I think) that although we think of the liquid part substance we put in fuel tanks (in our automobiles or model airplanes) as the fuel, in truth, there is another "fuel," without which the liquid part would be useless. Remember what it is? Right….just plain old air (in reality, the oxygen in the air).

Every internal combustion engine mixes air and another fuel of some sort….in our case, a liquid…glow fuel. The purpose of the carburetor is to meter those two ingredients in just the right proportions, and every individual engine has a requirement for a specific proportion of liquid fuel and air. Try to push in too much liquid without enough air, and the engine won't run at all. That's the purpose of the turbocharger on full-size engines….to cram in a lot more air than a simple carburetor or fuel injection system can handle.

Now…..suppose we were to find a way to run more liquid through our model 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. Voila! More Power! That's how it works, and it ain't all that complicated. Nor do we have to spend a lot of time thinking about it in the course of a normal day's sport flying.

However, there are some factors we do need to consider. As a practical matter, virtually all our everyday sport flying can be done on model fuel containing from 5% to 15% nitromethane. If you're flying something like a trainer or a Cub or similar model, there's probably no reason why 5% won't work perfectly well. Need a little more power? Move up to 10% or 15%. In most of our sport engines today, I really wouldn't recommend going any higher than that. It probably won't hurt anything, but it won't do you much good, either.

We sell more 15% fuel than any other single blend, and for good reason. Most of the popular engines on the market today are built to run on something very near that blend. Typically, European engines will successfully run on lower nitro blends, because they are built to do so. Why? In Europe, nitro can cost between $150 to $200 a gallon! Reason enough?

Nitro does more than just add power. It also helps achieve a lower, more reliable idle. One good rule of thumb for checking to see if a particular engine needs a higher nitro blend is to start the engine, let it warm up for a few seconds, set throttle to full idle and remove the glow driver. If it drops rpm, move up to a 5% higher nitro blend. If there is no discernible drop, you should be fine right where you are.

One of the most popular misconceptions is that by adding substantial nitro, the user will immediately achieve a huge power jump. Just ain't so. Most will be surprised to learn that in the 5% - 25% nitro range, you will probably only see an rpm increase of about 100 rpm static (sitting on the ground or on a test stand) for each 5% nitro increase. In the air, it will unload and achieve a greater increase, and it will probably idle better, too.

My pet rule is this: If you have a model that's doing well, but just isn't quite "there" powerwise, go up 5% in nitro. If that doesn't do it, you need a bigger engine, not more nitro!

Most of our popular sport engines in use today aren't set up to run on much more than 15% or 20% nitro. Increasing the nitro has the effect of increasing the compression ratio, and each specific engine has an optimum compression level. Exceed it and performance will probably suffer, not gain, and the engine will become much less "user friendly."

High performance racing engines, for example, are tuned entirely differently….compression ratio, intake and exhaust timing etc….and are usually intended to run on much higher nitro blends. One exception, of course, are racing engines used in certain international and world competition (FAI). By the rules, these engines are not allowed to use any nitro at all, and they go just as fast as those that run on 60 or 65%! The first question that comes to mind, then, is, "Why aren't all engines designed to run on no nitro, so we can all save a lot of money?" Ask any of the world-class competitors. Those engines are a serious bitch to tune and run, and are definitely not user-friendly! In fact, they are well beyond the skill levels of most average flyers. There's a price to everything.

Another statement we read or hear frequently is that nitromethane is acidic and causes corrosion in engines. It isn't acidic, and the manufacturers say it doesn't happen…..can't happen. However, at least one noted engine expert and magazine writer insists that it does. Flip a coin. (I once asked Dave Shadel, 3-time World Pylon Champion, and a fellow who works on more high performance engines than anyone I know, how frequently he encounters rust in engines that have been using high nitro blends. His answer? "Never.")

Why does nitro cost so much? While I have no clue as to the cost of manufacturing, other than it takes a multi-million dollar investment in a large refinery to produce it, there is one pretty good reason: There is only one manufacturer of nitromethane in the Western Hemisphere. Figure it out for yourself.

Also (and this will come as a big surprise), our hobby industry only consumes about 5% of all the nitromethane produced; and full-size auto racing about another 5% 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, explosives (yes, it was an ingredient in the Oklahoma City bombing) 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. (Remember….the guy used fertilizer, too.)

Hardly a month passes that someone doesn't call to ask, "I hear more nitro will make my engine run cooler. Is that true?" Nope. The higher the nitro content, the higher the operating temperature. Fortunately, in most of our sport engines, the difference in operating temps between 5% and 10% is negligible, and there are lot of other factors (proper lubrication, etc.), that are much more important.

Finally, remember in the beginning of this, we said that nitro adds power because we can burn more of it than we can methanol, for a given volume of air? This also means that the higher the nitro content of the fuel, the less "mileage" (or flying time) we will get. In a typical .40 size engine using 15% nitro, we can usually get a minute to a minute and a half flying time for every ounce of fuel. The Formula 1 guys are lucky to get 2 minutes out of an 8 oz. tank!

What's the practical side of this? If you go to a higher nitro blend, be sure to open your needle valve a few clicks and reset before you go flying. Otherwise, you'll be too lean, and could hurt your engine. Conversely, if you drop to a lower nitro blend, you'll have to crank 'er in a little.

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...

It seems This may start a war... I fear this may be wrong as they have removed the link to this from their website.

GlennCauley

iTrader: (3)

Wow, BaxterC

That has to be the LONGEST post I have seen so far.

Glenn Cauley
Ottawa, Canada

GlennCauley

iTrader: (3)

Hi Marco...

Sorry, I missed this post to me...

Glenn

BG

The content that was posted by Baxter was referred from
the following website.


http://www.powermasterfuels.com



Cheers Bill

Schrijver99

BaxterC Please give credit to the writer if you borrow an article

BaxterC

My humblest appologies, I posted a link to the site, then did some reading and found the article and thought that this would be great on for you guys, I forgot to put in that it was a copy\paste deal... SORRY

BaxterC

Thank you, This was from http://www.powermasterfuels.com/facts3.htm Again, MY humblest appologies

teammpp

I find it strange that they have removed the facts on fuel. Why would this be?

However, I believe that the article BaxterC posted from them (if that was the actual source) is inaccurate. Nitro content reacts to temperature. In higher air temperature more nitro is required to produce power whereas in climates with low air temperature less nitro is required.

To me this would indicate that while Nitro may aid in producing the power it only does so by acting as a coolant additive to ensure the proper detonation timing in line with other variables of the operation of the engine (squish area, pipe length, manifold, etc...) to maximise the power available.

BaxterC

I have seen many conflicting things since I posted the last few bits... I wonder if I was not right before I saw the article. I do know that low quality nitro actually burns hotter, but good quality nitro cools.

Thank you Palmaris.