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Nitro Engine by itself: bit.ly/48YGCvb
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This engine here which fits neatly into my hand has a displacement of 2.95cc but it has an incredible power output of 1.8 horsepower.
If you put it side by side with a 50cc 2 horsepower brush-cutter engine you realize just how incredible 1.8 horsepower from something this tiny actually is.
But things get even crazier if we take the displacement and the power output and calculate the horsepower per liter for this little thing. The number we get is: 610 horsepower per liter.
To put that into perspective, here’s the Koenigsegg Jesko, a 3 million dollar hypercar whose 5.1 liter twin-turbocharged V8 has a power output of 1603 horsepower when it runs on E85 ethanol fuel.
These numbers give us a specific output of 316 horsepower per liter. So around half of this, and this, which is a single cylinder nitro engine, costs around 80 dollars.
Now in order to match the specific output of this tiny engine we have to go beyond 3 million dollar hypercars and into current Formula 1 specifications, so from things money can buy to things that money cannot buy.
Current Formula vehicles output between 750-1000 horsepower from their turbocharged 1.6 liter v6 engines and their hybrid drivetrain. Nobody knows the exact numbers because they’re not published but we will take the highest number which is 1000 horsepower and we will say that all of it comes from the engine alone, in other words we will ignore the hybrid capabilities of the F1 cars. In that scenario we get 625 horsepower liter. So we’re able to outmatch the specific power of this engine only when we stack the numbers in favor of Formula 1. But the only reason we can actually do this is because I’m using my budget friendly engine as reference. If take something a bit more competition oriented from a company called OS engines, which specializes in making these, let’s pick this one the O.S.SPEED R2105. It costs around 650ish dollars I think but it makes 2.76 horsepower from 3.95cc and that gives a specific output of 791 horsepower per liter, so not even Formula 1 can touch this.
ow we have to answer some questions. How does this miniature little engine manage to have such incredible specific power? Well there are three reasons.
Number 1 this engine is a two stroke, and as we know, two strokes squeeze more power from the same displacement at the expense of longevity and emissions
Because this thing is a two stroke it doesn’t have camshafts, valves and valve springs. There’s nothing in here it’s just a giant heat sink with lots of coolant fins to maximize surface are and help the engine not overheat. Because there’s no valves and valve springs and because we have an absolutely tiny and very lightweight piston, rod and crank inside this engine it can rev to around 30.000 rpm.
And this is the most important reason, it’s the fuel. This is called a nitro engine because the full it runs on is called nitromethane. And nitromethane is an absolutely incredible fuel with an incredible power potential.
To observe that power potential we have to look at some numbers once again. This time let’s talk about power per unit of weight. If we put this on a scale we will see that it weighs 355 grams. Our power output is 1.8 horsepower which means that we make 5 horsepower per kilogram, or 2.3 horsepower per pound. Formula 1 makes 2.7 horsepower per pound or 6 horsepower per kilogram when the engine and the electric motor work together.
So Formula 1 powertrains have a better power to weight ratio? Well, yes, but that’s only because the actual fuel used in this engine is only 16% nitromethane.
But fortunately there exists something in this world which can demonstrate what happens with the power to weight ratio when you crank up the percentage of nitromethane in the fuel. You get this. And these are top fuel dragsters. Their fuel is 90% nitromethane the rest is mostly methanol. Their engines weigh around 226 kg and they output 11.000 horsepower. This gives us 22 horsepower per pound or 48.5 horsepower per kilogram
In case you’re wondering, no, there is no electric motor that has a better power to weight ratio. Koenigsegg’s dark matter motor weighs 39 kilograms and is capable of outputting 800 horsepower, sounds very impressive but it gives us 9.3 horsepower per pound or 20.5 horsepower per kilogram. The most power dense electric motor currently in existence is the eHelix SPM177-165 from a company called Helix in the UK. It allegedly has a power to weight ratio of 15.4 horsepower per pound or 33.9 horsepower per kilogram.
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