Engines 101: The Basics of How Engines Work | Toyota

just about everyone knows that a typical automobile gets its power from an engine under the hood but how many people can say they actually know how that engine works while a modern internal combustion engine is obviously an extremely complex piece of machinery the basic principle behind it is pretty simple let's take a closer look at a high level a gasoline engine can be thought of somewhat like an air pump except that the exhaust coming out is more of a side effect this pump's real purpose is to rotate an internal shaft which in turn rotates the vehicle's wheels it does this by connecting that shaft called a crankshaft to pistons that move due to a mixture of air and gasoline combusting inside their cylinders which creates a sort of chain reaction that keeps the engine turning before getting deeper into this process let's first touch on the two main parts of an engine on the bottom a lower block is home to the pistons cylinders and crankshaft the latter of which sends the engine's power out to the transmission and wheels and above the head contains the top of the cylinders and manages their airflow and combustion through valve train fuel injection and ignition systems so let's explain that part a little more you may have heard the term force drunk to describe a vehicle engine this refers to its four stages of operation first the piston moves down creating a vacuum in the cylinder chamber that pulls air in through precisely controlled intake valves next the valves close and the piston raises back up compressing all that air along with some gasoline that was mixed in from the fuel injection system now the fun part the ignition system creates a spark at the end of the spark plug creating a controlled explosion of compressed air and fuel that sends the piston back down then finally the piston moves back up pushing that spent air fuel mixture through the exhaust valves and out to the you guessed it exhaust pipes and since we're dealing with multiple cylinders with pistons all working from the same crankshaft each one essentially creates the four-stroke process for the next one pretty ingenious right now speaking of multiple cylinders let's talk about the various engine configurations four-cylinder engines are probably the most common design these days but who doesn't love a v6 or even a v8 these terms simply refer to the number of cylinders in the engine and their layout nearly all four-cylinder engines have their cylinders arranged in a row called inline or straight but it's also pretty typical to see engines group their cylinders into two banks connected at an angle a v doing it this way effectively cuts the engine length in half enabling it to fit more easily under the hood so a v6 three cylinders on either side creating a v-shape and what if that v-shape was opened up all the way a 180 degree angle well then you'd have what's called a boxer or flat engine design all right so what about those other numbers you always see 2.0 3.5 well that refers to the engine's displacement often simply thought of as its size that number is literally the volume in liters that the pistons displace with every engine cycle so essentially if you were to fill up the cylinders of a 2-liter engine with liquid it would take well 2 liters and if it's a 4-cylinder engine each one displaces half a liter so what's the end result of all this power the measurable output of an engine is called its torque basically the strength with which it turns its crankshaft torque is measured in pound-feet which as the name implies is the force created by one pound of weight at a distance of one foot imagine a one pound weight sitting at the end of a one foot wrench that nut is being turned with one pound foot of torque so now going back to the displacement concept bigger cylinders pull in more air and fuel typically resulting in more muscle they turn the crankshaft with more force which is perfect for large vehicles towing or even just spirited driving so now you're probably thinking isn't that horsepower well yes and no in fact horsepower doesn't technically exist okay yes that requires a bit of explanation horsepower is obviously a real thing but it's actually a calculation not a physical measurement like torque is it's basically torque over time so this means the faster that engine turns its revolutions per minute or rpm the more work it can do and the more horsepower it has put in extremely simplified terms torque times rpm equals horsepower but that doesn't mean making big horsepower is as simple as spinning the engine faster since that takes more and more energy as the engine speed increases and as that torque decreases the horsepower calculation eventually can't keep up either this is also why transmissions are so critical in keeping everything in the appropriate sweet spot but that's a topic for another video so that's the general idea behind internal combustion engines but this was just a high level look at the basics engines 101 if you will there's obviously a whole lot more to say about engine tech so be sure to check out the other videos in this series to learn more

Channel: Toyota USA

Views: 153,168

Keywords: Toyota, 2021 Toyota, Toyota 2021, how does an engine work, internal combustion engine, car technology, car tech, car engine, engine technology, engines, engine, engines 101, engines explained, Toyota USA, internal combustion engines, Toyota engine, Toyota engines, car engines, engine tech, how engines work, how it works

Id: gqK3dCpwzxE

Length: 5min 42sec (342 seconds)

Published: Fri Jul 30 2021