Why Nitro Engines Outpower Everything Else

This small engine, which fits perfectly in the palm of my hand, has a displacement of only 2.95 cc and a power of 1.8 horsepower. If you put it side by side and compare it to a brushcutter engine, which is 50cc and 2 horsepower, you realize how crazy this miniature's 1.8 horsepower is. But things get even crazier if we calculate this specific power for this engine, and it is the power per liter of engine displacement. So if we take the specs out of this engine and plug it into our formula, we'll get 610 horsepower per liter from this location. To put this incredible figure into perspective, here is the Koenigsegg Jesko.

It is a 3 million dollar hypercar, whose 5.1L twin-turbo V8 engine generates 1,603 horsepower when running on E85 5 ethanol fuel. So 1,603 horsepower is crazy, but if we calculate the specific power, we get only 316 horsepower per liter. So about half of what this thing can do, and this is a single cylinder

nitro

engine that costs about $80. Now, to surpass the specific power of this engine, we will have to venture beyond the $3 million hypercars and into the current territory of Formula 1. So, away from the things that money can buy, towards things that money can't buy. Now, current Formula 1 racing cars produce between 750 and 1,000 horsepower, no one knows the exact number, the numbers are never published, but it's somewhere in there, and the power comes from its 1.5-liter turbocharged V6 engine. 6 L and its hybrid.

Transmission that contains electric motors that add power to the engine. Now, to get Formula 1 past this, we'll cheat and pretend all the power comes from the engine alone. We are going to ignore the existence of electric motors, and when we do we will get 1.6 L, 1,000 horsepower and a specific power of 625 horsepower. So now we are overcoming this, but only because we are racking up the numbers, we are cheating, in favor of Formula 1, and really only because this is a very economical and beginner-oriented engine. If we dive into something more, competition oriented, let's say from a company in Japan called OS Engines, which specializes in making small

nitro

engines

and we're going to go with their r2105 engine, which costs around $650, so more than this, but you get 2.76 horsepower with 3.95 cc of displacement, giving you a specific power of 791 horsepower per liter.

So even Formula 1, which I don't know what kind of number twisting amount, can't touch that number. Now, the specific power output figures are interesting and exciting, but to experience the sheer fury of the power density of these

engines

, we're going to have to use a radio-controlled chassis, and I have one here, it just so happens, and This has pretty much

everything

we need. We have a real suspension, we have giant tires, four-wheel drive differentials, we also have a fuel tank, we have brakes, so almost

everything

is like a real car, and we take this, we're going to put it in, we're going to take a bit of exhaust, we're going to blow up the exhaust, we're going to connect our fuel lines and we're going to take it for a spin.

Did you know? I've spent most of my adult life playing with real engines, car engines, two-stroke bikes, four-stroke bikes, you name it, and I've never played with anything like this, because I thought it was just a nerdy toy. But boy, was I wrong, because this is a completely different world, and it's really fun, and the pure fury unleashed by this tiny engine is absolutely incredible. Yeah, yeah, that was a lot of fun, but now we need to answer the obvious question. And the obvious question is where the incredible specific power of the tiny nitro engines really comes from.

Well, there are three main reasons. And the number one reason is that this is a two-stroke engine and the giant exhaust probably gave it away. And, as we know, two-stroke engines are capable of generating more power per liter of displacement, compared to four-stroke engines, because they have twice the power strokes, but they do so at the expense of engine longevity and the emissions. The second reason is that since this is a two-stroke, there really isn't anything important in terms of mechanics. This is just a giant, hollow heatsink with lots of big cooling fins to maximize surface area, to help the engine dissipate as much heat as possible and keep it from overheating, because there's nothing important here, like cams, valves. or valve springs, and because we have a very light and very small piston rod and crankshaft here, this can rev to around 30,000 RPM.

And, as we know, power is essentially torque times RPM. So if you can accelerate very high, you will inevitably generate a lot of power. Reason number three is that this is called a nitro engine, because the fuel it runs on is called nitro methane. And the power potential, hidden within the nitromethane, is absolutely mind-blowing, and to see how mind-blowing it is, we're going to look at and analyze another very important engine spec, the engine spec statistic, if you will. Up to this point, we have been talking about engine power per liter of displacement. But now we will talk about something that may be more revealing: the engine power per unit of weight.

So, per kilogram or pound or whatever. We'll do it, we'll do it because you can actually calculate power per liter. Because, for example, let's say you add a turbocharger to an engine. A turbocharger does not increase engine displacement, but it certainly increases engine power. So, you can make the engine have a very high power per liter of displacement, you can cheat that statistic, but you can't cheat the power per unit of weight, because a turbocharger certainly adds weight to the engine, and that's why the power per unit of weight, can be more revealing of how intelligent the engine is in drawing power from its physical existence, its mass, and how technologically advanced the engine is.

Now, if we take a small scale, turn it on and put our little motor on the scale, we will see that the motor weighs 355 grams. If we take that and take the power output, we get that this engine makes 2.3 horsepower per pound, or 5 horsepower per kilogram. Now we're going to compare it to Formula 1 once again, but this time we won't have to cheat, because Formula 1 engines are probably the most technologically advanced engines out there. Now, the Formula 1 engines are 1.6 engines that weigh 150 kg. The engine alone produces 850 horsepower. The electric motors have about 150 horsepower. Now if we take 850 and 150 kg, we get the Formula 1 engine power of 2.6 horsepower per pound or 5.7 horsepower per kilogram.

So now, Formula 1 engines surpass this, but they really only surpass it because the fuel this engine runs on is only 16% nitromethane. It is only 16% nitromethane, because it is the highest concentration of nitromethane that can be legally purchased in the EU without a license. The rest is methanol and contains 10-20% lubricating oil, because it's a two-stroke engine, it needs it. Now, just getting a license in the EU is not that difficult, but I don't really need it because I don't plan to compete, so 16% nitromethane is more than enough for me, as you can see and as you have seen, makes this thing more than capable of dumping our chassis and taking loads. of fun.

However, there is something that exists in this world, fortunately with a much, much higher concentration of nitromethane, that can show us that nitromethane is more powerful than technology. And that something is called Top Fuel dragsters. Now, Top Fuel is called Top Fuel because these dragsters run on 90% nitromethane, the rest, the remaining 10%, is mainly methanol and many other additives. Now, the engines in Top Fuel dragsters weigh 226 kg and have a power of, wait for it, 11,000 horsepower. When we take these two numbers, we get 22 horsepower per pound or 48.5 horsepower per kilogram. As you can see, they managed to make even Formula 1 look like a joke, and the totally crazy thing about it is that these engines, their basic anatomy in architecture is based on a design, which is pretty much from the stone age in comparison to Formula 1. 1.

It's actually kind of stone age compared to even your car engine, because the engines, the basic architecture of the Top Fuel engines, are based on second-generation Hemi engines. That means, two valves per cylinder, pushrods, and a supercharger, which is based on a root-type supercharger, based on an archaic GM design to rescue two-stroke diesel superchargers. These were adapted for automotive use in the early days of the Top Fuel sport. We have an engine that is quite old, but the power potential of nitromethane makes up for it, to the point that there is nothing on planet Earth that humans have ever made that produces more horsepower per unit of weight. .

Nothing, actually I know there's one thing, one thing, and it's called SSME, and it stands for Space Shuttle Main Engine that produces 93 horsepower per pound or 205 horsepower per kilogram. But of course, comparing anything to the space shuttle engine doesn't really make sense, because it's not something you can hope to own or operate, and I mean, it took NASA's budget and expertise to develop and build this one. engine. On the other hand, Top Fuel dragster engines contain many off-the-shelf parts and can be built, owned, and bred by anyone willing, and they certainly don't cost millions. In fact, they are extremely affordable for the amount of power they get.

Now, in case you're wondering, no, there are no electric motors that can outperform Top Fuel engines in terms of power per unit of weight. Take Koenigsegg's latest electric motor, I believe, called dark matter. It weighs 39 kg and produces 800 horsepower. Very, very impressive, but it gives us only 9.3 horsepower per pound or 20.5 horsepower per kilogram, so it's not even close to Top Fuel. In fact, dark matter is not the most power-dense electric motor out there. The motor that claims to be this is called eHelix SPM177-165, from a company called Helix in the UK. It supposedly has a power-to-weight ratio of 15.4 horsepower per pound, or 33.9 horsepower per kilogram.

Very impressive, again, less than Top Fuel engines, and comparing electric motors to any type of combustion engine like this, ignoring the fact that to power a freely moving vehicle, electric motors need very heavy batteries, you really don't have sense. because these batteries are certainly much heavier than the fuel and fuel tank needed to power a top fuel dragster. So, the secret is in the fuel itself. Nitromethane is an extremely powerful fuel that contains a lot of energy in itself, so running an engine on nitromethane generates impressive power. Surprisingly, no. In reality, nitromethane contains less energy than the gasoline available at the nearest pump.

Gasoline has an energy density of 44 MJ per kilogram. Methanol has an energy density of 22.7 MJ per kilogram, while nitromethane has an energy density of 11.2 MJ per kilogram. But here's the problem: Running an engine on methanol will produce more energy than running it on gasoline. Running it on nitromethane will produce even more energy than running it on methanol. Therefore, the fuel with the least amount of energy produces the most energy. As? Well, the secret is in the air-fuel ratio. Now, to create combustion, we need air, which is all around us. Now, air itself does not contain energy, like fuel.

However, without air we cannot take advantage of the energy available in the fuel; In other words, if we remove the air, then the fuel cannot burn. Gasoline now has a stoichiometric air-fuel ratio of 14.7:1. Stoichiometric simply means that with this air to fuel ratio, all of the air and fuel will be burned. In other words, it takes 14.7 pounds, or kilograms, or whatever, of air to burn just one pound, or kilogram, or whatever, of gasoline. As you can see, we need much more air than gasoline to harness the energy inside the gasoline. And that's why we're so obsessed with trying to make our engines essentially breathe better.

Increase the number of valves in the engine, or change the size and shape of the intake, ports and intake manifold, or get a larger throttle body, or change the camshaft specifications to get cams with higher lift and longer duration, and even turbochargers. and superchargers. These are all just tools in an endless battle to try to get more air into the engine, because we need a lot of air to harness the energy of the gasoline. Gasoline has the energy and gasolineproduces power. And modern fuel injection systems and even carburetors have no problem getting a lot of gasoline into the engine, but there's no point in doing so if you can't get the corresponding amount of air into the engine, and that's the hard part because we need a lot more air than gasoline, and getting a lot of air into the engine over a wide RPM range is very, very difficult.

But nitromethane and methanol have a secret here, an ace up their sleeve, and it only becomes obvious when we look at their chemical formulas. The important thing here is O, oxygen. Unlike gasoline, methanol and nitromethane carry their own oxygen, it's already there. Methanol has one oxygen atom per molecule and nitromethane has two. And oxygen is what you need to burn fuel. Because they already carry their own oxygen, the stoichiometric air-fuel ratio for methanol is 6.45:1. For nitromethane it is 1.7:1. In other words, you only need 1.7 kg of air to burn 1 kg of nitromethane. And because you have oxygen in the fuel, it means you suddenly become much less dependent on trying to get the engine to breathe better.

You don't need to put as much air into the engine to burn a lot of fuel. And the fuel is what generates the power, because the fuel contains the energy. The more fuel you can burn, the more energy you can generate. And, although nitromethane has about a quarter of the energy density of gasoline, more than eight times as much nitromethane can be burned during each combustion event. But this ridiculous air to fuel ratio also explains why we don't use methanol or nitromethane in daily driven vehicles, because yes, you can generate a lot more power, but you need to burn a lot more fuel, which means that the efficiency of fuel decreases. , your MPG becomes horrible.

But here's the important thing: Top Fuel dragsters never actually run on this stoichiometric 1.7:1 air-to-fuel ratio. What works is 0.5:1. In other words, they burn more fuel than air. Now, with gasoline, if you use too rich a ratio, something like 9:1, you'll actually generate less power than if you used something closer to stoichiometric. And this is simply because it will not be able to burn the gasoline. But because nitromethane carries its own oxygen, and it carries twice as much as methanol, it has the potential to be something called a monopropellant. In other words, it can burn on its own, it doesn't even need atmospheric air and this means that the more fuel you add, the more power it will generate.

Yes, outputs start to decline a little the further you get from the stoichiometric ratio of nitromethane, but more power is even more power, and that's why the fuel pumps on Top Fuel dragsters can flow 100 US gallons or 378, 5. L of fuel per minute and that is why V8 engines have 42 individual fuel nozzles. There are 10 injectors in the injector cover above the supercharger, 16 in the intake manifold and another 16 in the cylinder head, two for each of the eight cylinders. Another really convenient benefit of nitromethane is that it has a very high heat of vaporization. Nitromethane requires a lot of thermal energy to go from a liquid state to a gaseous state, in other words, when the nitromethane enters the chamber and as it vaporizes, it absorbs a large amount of heat from the chamber, which helps keep the engine cool and is also one of the main reasons why top fuel dragsters can run without radiators or water passages in the head and block.

Now the lack of water passages in the head and block and the fact that they are solid chunks of aluminum makes the head and block incredibly strong, but the power of the nitromethane is such that it can still blow them to pieces and this is why engines have safety harnesses on them to prevent the supercharger and other engine parts from being thrown towards innocent bystanders if the engine explodes. Now, something

else

that is also often said about Top Field dragsters is that the engines are rebuilt after each race. Actually that's not true, engines are not rebuilt, they are opened after each run and everything is checked to see if it is in tolerance and within spec and if not it is replaced but very often not many parts are replaced, most of the time.

The parts are returned to the engine and the engine is run again, so what is actually done is more of a prevention of a rebuild than a full scale rebuild. But make no mistake, nitromethane is still crazy. In fact, it's so crazy that the NHRA, which is the governing body of Top Fuel racing, had to limit the concentration of nitromethane in the fuel to 90%, even though even more power could be generated by running at 98%. But this comes with a higher risk of blowing up engines all the time and no one wants that. Interestingly, 100% pure nitromethane cannot be used because nitromethane, if not mixed with methanol, tends to explode rather than burn.

Now, the sheer power of nitromethane is also the reason why Top Fuel dragsters do not run the full quarter mile or 402 m, but rather their travel has been reduced to 1,000 feet or 304.8 m and this is because If you give them a full quarter mile run they reach speeds such that controlling and stopping them becomes very difficult and negatively impacts the safety of the drivers and everyone

else

on the track. But still, even at the end of their short 1000-foot drag strip they manage to reach speeds of around 330 mph or 540 km per hour. That's the trap speed, but the acceleration is even more mind-boggling, and to put it in perspective, here's the Rimac Nevera, which is a very, very expensive electric hypercar that accelerates from 0 to 62 mph or 0 to 100 km. per hour in 1.95 seconds, very, very fast and I think at this point it's the fastest you can go from 0 to 60 in anything. legal road that can be bought with a lot of money.

Now, the inspiring thing is that recently a group of students from Switzerland built the fastest electric vehicle in the world and broke the Guinness World Record for the fastest accelerating electric vehicle. It's obviously not road legal, but it accelerates from 0 to 62 mph in 0.956 seconds. Now a Top Fuel dragster is even faster, hitting 0.8 seconds, but not 0-62 mph. 0 to 100 in 0.8 seconds and if that's not impressive, I honestly don't know what is. Something that might have crossed your mind while watching this video is the characters from the movie Fast and Furious pressing that button on the steering wheel to make the car go faster.

Were they injecting nitromethane into the engine? No, they were injecting nitrous oxide. It's a different thing, nitrous oxide is a gas, nitromethane is a liquid, however the general idea behind nitrous oxide is very similar to that of nitromethane and you can think of NOS or nitrous oxide as the cheapest and simplest form. to achieve some of the benefits of nitromethane. In a normal engine, atmospheric air is made up of 78% nitrogen, 21% oxygen and 1% other substances. What gasoline needs to burn is oxygen. Now nitrous oxide is 66% nitrogen and 33% oxygen. When we inject it into the engine, it vaporizes and releases oxygen, which means that nitrous oxide acts as a kind of chemical turbo, so to speak, because it increases the amount of oxygen in the engine.

If you have more oxygen, you can add more fuel and generate more power. But nitrous oxide is not a fuel. If you took a match and struck it in a room full of nitrous oxide, nothing would happen. Instead, nitrous oxide can be thought of simply as a more oxygen-rich substitute for atmospheric air. Now nitromethane is at the opposite end of that scale, it's a monopropellant, you don't even need a match, it can burn itself and this gives it almost infinite power but it also makes it quite dangerous