Everything Everywhere Daily: History, Science, Geography & More - The Internal Combustion Engine

Episode Date: December 4, 2021

One of the technologies which have helped make the modern world is the internal combustion engine. Without it, the world would be a very different place today. Yet it wasn’t a technology that appeared fully formed. It was developed incrementally over a century. To get it to a point where it was viable for use in vehicles took numerous innovations. Learn more about your ad choices. Visit megaphone.fm/adchoices

One of the technologies which help make the modern world is the internal combustion engine. Without it, the world would be a very different place today. Yet, it wasn't a technology that appeared fully formed. It was developed incrementally over a century. To get it to a point where it was viable for use in vehicles took numerous innovations. Learn more about the internal combustion engine, how it was developed and all the problems that had to be solved on this episode of Everything Everywhere Daily. Do you ever climb into bed ready to sleep,

only to have your mind start racing the moment your head hits the pillow? Thoughts bouncing around, replaying the day or jumping ahead to tomorrow? That is exactly why Catherine Nikolai created Nothing Much Happens. Each episode is a gentle, cozy bedtime story where, well, nothing much happens. No drama, no tension, nothing you need to follow closely. Just soft narration, calming repetition, and soothing sensory details designed to help your mind slow down and your body relax. It's not about entertainment, it's about rest. and millions of listeners around the world use it every night to quiet their thoughts and finally fall asleep.

If you've ever struggled to shut your brain off at night, this might be exactly what you've been missing. You can listen to Nothing Much Happens wherever you get your podcasts. Episodes are every Monday and Thursday. I think a good place to start this discussion is to define what an engine is. An engine is something that converts combustion into work. It is distinct from a motor that converts electricity into work. Even though the terms are often used interchangeably, motors and engines are different things. The first engines were steam engines. A steam engine was based on creating heat either through wood, coal, or some other combustible substance, and boiling water.

The steam would then turn a turbine, which would turn a crank that could do work. The key to a steam engine was simply the creation of heat so water could be boiled. What was burned to create the heat was dependent upon what was available and what was cheapest. An internal combustion engine works differently. An internal combustion engine relies on the combustion of fuel and the subsequent expansion of the hot gas which is created. The combustion has to be enclosed in a space to capture the pressure of the expanding gas, or in other words, it has to be internal. An internal combustion engine is far more difficult to engineer than a steam engine for this reason. The basics of a steam engine were first built in ancient Greece.

The internal combustion engine, however, wasn't developed until the second half of the 19th century. The first internal combustion engine was developed by the Belgian engineer Jean-Josef Etienne Lenoir in 1859. His engine was rather crude insofar as it was really just a steam engine which was converted to burn coal gas. The person who was considered the originator of the modern internal combustion engine was the German engineer Nicholas Otto, who defined the auto cycle in 1877 and built the first multi-stroke engine. Now you might be asking, what is the auto cycle? The auto cycle describes the four-stage process by which fuel is burned in an engine. I'll explain it briefly here because it's the basis of everything going forward.

It's how a typical four-stroke engine works in most cars in the world. There are variations on this process, and smaller engines like lawnmores use a two-stroke process. But for the purposes of this episode, I'm going to be talking about the four-stroke process. Everything I'm talking about takes place in a cylinder with a movable piston at the bottom of the cylinder, with fuel and air intakes and an exhaust port at the top, which can be turned on and off. The first stroke is called the intake stroke. Here the piston will pull down creating a suction that will pull in a fuel air mixture through the open intake valve at the top. The second stroke is the compression stroke.

Now that the cylinder is filled with a fuel air mixture, the intake valve is closed and the piston moves up compressing the fuel air mixture. All the valves are closed in this phase. The third stroke is the combustion stroke. A spark will combust the compressed fuel air mixture in the cylinder, creating a small explosion, and the force of the explosion will push the cylinder back down. The fourth and final stroke is the exhaust stroke. In this stroke, the piston goes back up the cylinder, pushing the exhaust out of the exhaust valve. The piston, which is being pushed up and down, are connected to other pistons via a crankshaft,

which ensures that when one piston is down, another piston is up. This is why engines will always have an even number of pistons and cylinders. Most cars today will have six or eight cylinder engines, but there are some small cars with four cylinders, and some powerful high-end cars that might have 10 or 12 cylinders. The crank shaft, which connects the pistons, is also what drives whatever work needs to be done by the engine. In the case of a car, it would drive the transmission.

Everything I've just described isn't necessarily that hard to understand, at least at a conceptual level. However, it creates a ton of problems to make it work in practice. If you remember back to my episode on electric cars, steam and electric automobiles were actually as popular as internal combustion engine automobiles up until about 1910. What eventually made internal combustion engine automobiles dominate was solving many of the problems that went along with them.

So, based on what I just described with the four-stroke cycle, let's look at all the engineering problems that need to be solved. First, there's the fuel air mixture which goes into the cylinder. You can't just fill a cylinder with a bunch of liquid gasoline. Liquids don't compress very well. It needs to be put into a mist and mixed with air. This used to be done by a device known as a carburetor. The act of mixing air and fuel together is called carbureation. Today, most cars will do the same thing with a device called a fuel injector. Air has to come from outside of the engine. Moreover, the air needs to be clean, so it requires an air filter to remove any particulate matter. This is also why automobiles will stall if they're underwater. Some specialty vehicles will

have a snorkel that puts the air intake over the roof so they can cross rivers. Once the fuel air mixture is in the cylinder, then it has to be ignited. This is done with a spark plug, which allows electricity to create a spark between a gap at the top of the spark plug. The spark has to be timed with the maximum compression of the fuel air mixture. The piston and the cylinder are both made out of metal, and metals don't like to rub against each other. That means you need some sort of lubricant between the piston and the cylinder, which is where motor oil comes in. Without motor oil, the friction between the piston and the cylinder would cause them to get stuck, and the entire engine would seize up. In the exhaust stroke, the waste from the

combustion has to be eliminated and then has to go somewhere. That is all directed out the exhaust pipe. Some cars will have catalytic converters that will convert certain toxic gases. As I said before, the combustion stroke is actually a small explosion, and explosions are noisy. Automobiles can be pretty noisy, but they would create far more noise without a device to reduce the sound, called a muffler. If you've ever driven a car

without a muffler, you know just how loud a car can really be. And a muffler is fundamentally just an acoustic device. The cycle is a process that goes over and over. The question is, how does the cycle get started? In really old automobiles, there was a crank that you had to physically turn to get the cycle started. Eventually, this was moved to an electric motor called a starter. The electrical starter, as well as the spark plug, necessitates an electrical system to make the engine work. That requires a battery to store the electricity, but also a generator to create electricity. The mechanical energy from the engine is used to generate

electricity, which is stored in the battery. In modern cars, this is called an alternator because it creates an alternating current. So this explains the fuel and air coming in, the exhaust going out, and the lubrication of the piston and cylinders. However, there is another huge problem. Internal combustion engines are actually very inefficient. Efficiency is defined as how much of the energy in the fuel is transferred to motion. In the most efficient internal combustion engines ever, they have an efficiency of only 40%. And most automobiles might just have an efficiency of around 20%. If only 20% of the energy in the fuel is converted to work, where does the rest go?

The answer is, it's converted to heat. Heat is a huge problem. Heat makes metal expand, which is really not great if there are moving parts. And it can cause the metal to crack and deform. If you've ever put your hand on or near an engine after you've stopped a car, you have an idea as to just how hot it can get. You can literally cook food on an engine. There are many videos online of people cooking food wrapped in foil on a car engine.

And hint, if you're ever in a situation like a blackout or a hurricane and have no means of cooking food, this is an inefficient, if effective, way to cook. This means that a cooling system has to be integrated into the engine. In most engines, there will be a fluid that runs through chambers in the engine block to carry away heat. The fluid is then run through a device called a radiator, which has a high surface air, and air is blown over the radiator to cool the fluid. The entire engine cooling system requires fluid, a pump to move the fluid, tubes and hoses to channel the fluid, and finally belts to operate the fan.

Everything I've just gone over is required for the engine to function. If the lubrication, air intake, cooling, fuel injection, or electrical system were to fail, then the entire thing will just stop. If you've owned an automobile long enough, there's a good chance, one, if not all of these things, has probably gone wrong in your car. The more you think about the whole system, it really does seem like a Rube Goldberg device. And I haven't even gotten into the other vital systems on a car such as transmission, brakes, and suspension.

Nonetheless, over decades, engineers have gotten very good at just making everything work. It was getting all of these parts of an engine to function properly and in unison, which made the internal combustion engine automobile possible. The associate producers of Everything Everywhere Daily are Thor Thompson and Peter Bennett. Today's review comes from listener and be verbal on Apple Podcasts in the U.S. They write, Gary has hit his stride. In Everything Everywhere Daily, Gary is pursuing what matters most to him,

and luckily also to a large swath of people curious about life in the world, both historic and current. By eliminating any needless fat, Gary has created an informationally nutritious podcast that can be consumed each day in just a few minutes. Five stars. Well, thanks, and be verbal. You'll be happy to know that everything everywhere is part of a balanced media diet. It has 100% of the daily recommended allowance of facts and information.

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