The Basics of How Engines Work (2021) [video]
youtube.com
youtube.com
-Gasoline vapor is highly flammable, and when you fill a confined space with flammable vapor and ignite the air, it causes a small explosion.
-If you set things up carefully, you can use this kind of explosion to push really hard on something, just like firing a cannonball out of a cannon.
-The way a car engine makes the wheels spin is very similar to pedaling a bicycle. When you push down on one pedal, in addition to driving the wheel forward partway, it also maneuvers the other pedal into place, ready to be pushed down next. When you get down to it, powering a bike is just a sequence of well-timed downward pushes in an alternating pattern. The bike takes care of the rest.
-A car engine combines the two concepts. Instead of human feet, it uses small, controlled gasoline vapor explosions in a repeating pattern that "pedals" the car's wheels and causes the car to move forward.
-The timing is crucial. All the complicated engine mechanisms you see are there to "reset" each explosion chamber (like reloading a cannon) so that it's ready to go in time for the next push: flushing out the exhaust gases and refilling the chamber with fresh aerosolized gasoline.
So there you go. Cars are basically just 4-wheeled cannon bicycles.
Just wrapped up an ~1100mi roadtrip with my RAV4 Prime and it got ~45mpg. Charged it whenever possible too, so got maybe ~150mi off on pure EV, and plenty of recharge over the many hills of upstate/western NY. Love this car!
I’m dealing with NYC’s building emissions Local Law 97, and I’ve been using a car engine analogy to try to understand how energy consumption, efficiency, and component factors combine to permit NYC determine a building’s carbon emissions (allowed emissions, excess emissions, and fines for the latter).
Rather a different style of explanation. Not so much fancy graphics and more things like demonstrating the oil flow by banging a hole in the side with a hammer.
- Start by talking about what "everyone knows" to someone watching a basics video. Ugh.
- describe something as "'obviously' extremely complex" to an audience who don't know the basics.
- in the next breath, describe it as a 'pretty simple' principle. Ugh.
- ignore simple principles and talk about air pumps with exhaust as a side effect.
- the purpose is to rotate a shaft. [audience who doesn't know the basics knows what a prop shaft is, despite it not being pictured or explained].
- which in turn rotates the wheels [also not pictured].
- it does this by connecting that shaft to pistons that move due to a mixture of air and gasoline combusting inside their cylinders which creates a sort of chain reaction.
- let's talk about the block and head
I think some basic introduction is missing - drawing attention to the fuel having stored energy that we want to use to move a car, that burning a drop of fuel makes a small explosion. Explosions push outwards in all directions and if that push can be captured and used to turn a car's wheels, it can move the car. That's where the engine comes in at all. Place for the explosion, comparison to canon/space rocket/firework/gun/steam train turning it into linear movement, crankshaft turning it into rotary movement, comparison of spinning a playground ride or a bike wheel by hand, giving it occasional pushes, and that moves the piston back and squishes the exhaust gas out, and how it would be a lumpy ride with big jolting pushes and then coasting for a bit, so ...
Look at the YouTube comments:
- "where does the pistons get the power initially to the moving down and ignition? I see it does it with the lingering power from the exhaust pipe after the first stroke cycle but where does the power come initially?"
- "Good questions, hopefully someone smarter than me finds this comment cause I’d like to know too"
A five minute basics video that says "cars get power from their engines" and purports to show you "how an engine works" but doesn't explain where the power comes from, leaving the audience confused about how the engine works. More confused comments:
- "It's a good video [...] I looked at it once and figured out what it means in the engine. Where the pistons are located and that they are powered by the crankshaft."
- "I feel so slow. I'm watching this and I'm already getting lost lol. Cars are too complicated for me, I guess."
- ""First the piston moves down"...HOW??? LOL...that is OBVIOUSLY not "First", because what caused that?"
Finish by saying "there's obviously a whole lot more to say about engine tech" another 'obviously'. Don't give any examples.