Chapter 26
Chapter 26
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Translator: MadScientist
Chapter: 26
Chapter Title: Magic Stone Engine (4)
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First off, what is an engine?
On Earth, it's a device that converts the up-and-down motion of a piston into rotational motion through an explosion stroke.
That creates tremendous heat and shock, and the engine has to withstand that extreme environment.
The cylinder, in particular, needs to have a gap with the piston on the micron level.
That's the only way it can endure tens of thousands or even hundreds of millions of cycles.
Of course, it needs engine oil and such too.
Beyond that, there are all sorts of adjustments needed, like fuel injection volume, intake, and exhaust.
In the old days, they handled this manually—mechanically, that is.
The classic example is a manual clutch.
Shifting gears by hand.
But as technology advanced, semiconductors made their way into cars.
Thanks to that, mechanical controls shifted to electronic ones.
Anyway, we couldn't just bring an engine like that straight over.
For one thing, there's no crude oil, and besides, it pollutes the environment.
We can use mana right away without any issues, so why bother with petroleum?
Plus, refining crude oil involves all sorts of processes, which is a hassle.
So I started thinking about how to harness the mana inside magic stones.
My first idea was to extract the mana from the stones and make it explode.
There are explosion spells in magic, after all, so I figured I could recreate the explosion stroke that way.
I tested it first thing, but of course, it failed.
Low speeds were fine, but as soon as the RPM picked up a bit, the casting speed couldn't keep up.
Speed up the casting, and the formulas got way too complex.
Engines are precise and durable, sure, but not complicated.
Above all, they were a pain to make.
So after some thought, I had a realization.
I could build a rotary engine!
That way, I wouldn't need to tweak the formulas, and even relatively slow speeds could generate power.
I built one like that.
But it still couldn't keep up with the speed.
Then I thought of hydroelectric power.
How could I integrate that into an engine?
So I extracted mana from the magic stone and used fire and wind magic together.
At the same time, I made the fire magic carry an explosive property.
Just like how a waterwheel turns to generate power in hydroelectric plants.
When the flames touched something resembling a waterwheel, it exploded and pushed it forward.
And with the wind constantly directing it in one direction, I finally had an engine.
The piston method failed because it had to repeat explosion, stop, explosion, stop.
The rotary method was similar and failed too.
But the one inspired by hydroelectric power didn't need that!
I just had to keep blasting fire and wind in one direction continuously.
The downsides were high energy waste and low output.
So how could I improve this engine?
For mining minerals, it needed serious power.
Not just fast like a car—strong torque.
Oh, and for the record, speed doesn't equal power.
Just because a person can pedal a bike at 20-30 km/h doesn't mean they're super strong.
Low torque with high RPM naturally means higher speed.
Anyway, to make it produce even more power, just amp up the explosion force.
And make the turbine—or waterwheel—bigger.
"Hold on a second!"
"Yeah? What's up?"
Esili raised her hand urgently and asked me a question.
Her face was full of confusion.
"Um, I only got as far as... piston?"
"Ah, it's fine. Esili, and Pretina too—this is stuff you haven't studied. This is just an explanation for the professor."
I'd made the magic stone engine a few years back.
The professor's been busy, and with all his projects, he might've forgotten.
That's why I skimmed over things like thermal expansion, compression, and heating in the explanation.
Esili looked a little deflated.
"...I didn't get that either."
"I'll explain it slowly later. But if you're not going to grad school, you don't need to know that much. Just enough to calculate values under specific conditions."
For example, values when heating something fully sealed on all sides.
Or pressure and temperature of a fluid flowing in one direction.
"...Are you teasing me?"
Esili narrowed her brow more with every word I said.
Whoops, better move on.
"So this improved version finally uses a piston."
"Is that important?"
"Of course. Turbines are sneakily underpowered."
The method I'm using in this engine is simple, in layman's terms.
Inject air in one direction.
The air flows through the passage, pushing the rotor—or waterwheel—causing it to spin.
Then the air exits through the opposite passage.
Repeat.
Incidentally, the fire and explosions from magic produce almost no pollution.
It's converting mana directly into force.
Exhaust gases come from combustion changing materials and releasing energy.
Magic just uses the force itself, so no exhaust.
Fire magic still needs some air to sustain, so nearly none.
Anyway, turbine efficiency and power drop sharply as size shrinks.
They rely on high-speed rotation for output.
Magic helped mitigate that somewhat, luckily.
"Now we really need pistons. Unless we want an engine the size of two carriages hooked together."
Esili and Katiranya looked shocked at my words.
"That's definitely big."
"Yeah, practically house-sized, right?"
Hence the need for pistons.
Can't make the turbine bigger, so high output at low torque.
"That's why we have to head to the dungeon next to the Mana Wasteland. To get the minerals there."
"Can you tell us what it is?"
I nodded at the professor's question.
No reason to hide it.
"No official name yet. Simply put, it's a mana-reactive explosive mineral. Processed right, it can be used as a gem."
"What? Something like that exists?"
It does.
I'd seen it once while tinkering with improvements and thought it was amazing.
Like sodium on Earth.
Wait, sodium is sodium, right?
Anyway, this sodium reacts with water molecules, generating heat.
Which leads to explosion.
There's a similar mineral here.
That's what I plan to use.
This mineral explodes when injected with a certain amount of mana.
Not much data, but it should work inside a cylinder.
The principle is simple.
Continuously inject mana into the gem.
The gem explodes, pushing the piston down.
Temporarily, the mana's amount in the gem drops.
If no explosion happens then, the piston rises, compressing the space.
Then the steady mana supply refills the gem, and boom again.
Repeat.
"This lets us get high output even at low torque. Sure, we could do it all with magic, but that's not my style. Plus, repurposing what's already there is faster."
I looked away from the blackboard, and everyone except Pretina and the professor was lost.
Esili was trying hard but just groaning.
Katiranya was filing her nails.
Hmm, need to simplify.
"Hit it with a hammer, it goes down. It comes back up, hit it again. That's the idea."
"Got it."
Simple explanation, and her face lit up instantly.
Pretina saw that and hid a smile behind her fan.
"Really?"
"Really, Lady Apontuna."
Hey, no fighting again.
I smacked the blackboard a couple times to refocus them and said,
"So, let's head out!"
"Right now?"
"Yes, Professor! We can't start without it."
I quickly herded the three out of the lab.
And so we headed to the Dungeon of Greed, located next to the Mana Wasteland.
◇◇◇◆◇◇◇ "Sorry, we can't take the carriage from here."
"Got it. Alright, everyone out."
We'd arrived about 30km from the Mana Wasteland.
Far yet close, close yet far.
Just barely outside the wasteland's dangers.
But still a highly dangerous place, so caution was key.
Including me, we'd all changed into practical clothes.
Light leather armor, pants instead of skirts.
The different colors gave a fresh feeling.
But there was one problem.
"Don't we have zero frontliners?"
Surprisingly, no shieldbearer or even knight up front.
A warrior would've eased my worries.
The professor waved off my concern.
"Edn, no worries, Edn. As your professor, I'll handle—"
"Cut the nonsense. I'll take point."
Katiranya stepped forward and cut him off.
The professor frowned a bit, but she ignored it.
"Frankly, you all can just follow. But Edn, when we get back, you owe me money... mmph."
"Haha, got it."
No, Pretina too.
Everyone's itching because I haven't told them I'm the author?
Even if Esili's the only one who doesn't know here.
Far from the wasteland, no people around.
Hmm, should tell Esili later.
Not now.
I pried the hand off and gave a quick explanation.
She seemed to get it, so I sighed in relief.
"Shall we go?"
We started through the dense forest.
If the map was right, about 5km to the dungeon.
As Edn's group slowly headed toward the dungeon, watchers lurked behind them.
"They're on the move now."
"I can see that. But is this really the plan?"
"What do you mean?"
The black-robed figure asked the white-robed one in puzzlement.
The white robe sounded exasperated.
"Helping nobles? What the hell is the point?"
"Didn't you hear? Eliminating that Edn guy smooths our plans. His tech is a huge threat to us right now."
Nipping threats in the bud.
Sounds like removing variables, but the white robe still didn't get it.
"A real threat to us?"
"Yes. Plus, cozying up to empire nobles isn't bad. Using what we can isn't wrong."
With that, the black robe slowly moved out.
The white robe glanced at Edn's group, then followed.
But they missed something.
"Huh? Humans."
"Fox... beastkin?"
A pink-furred fox beastkin had encountered Edn's group.