With the above knowledge you should be frustrated by now. In most vehicles I have seen, what you see as the RPM indicator (revolutions per minute) on your dashboard, is the rotation of the above mentioned crankshaft. This is what makes the engine running and the crankshaft rotating giving us the ability to connect it to wheels and roll. Assuming that two of the four pistons are compressing the mixture inside the chamber (such as the first image’s chambers 1 and 4), when the spark plug will ignite the mixture the pressure from this “explosion” will force those two pistons move downwards while the middle two will have an opposing movement since they were already down. Check out the first image again to locate the crank at the lower part of the engine that holds the pistons with the connecting rods and has a flywheel at one of its end. In the previous paragraph I talked about the rotating crankshaft. This means that valve timing is crucial since valves should be consistent. As you have probably already guessed, the intake opens to fill the combustion chambers of the cylinders with the mixture (fuel + air) while the exhaust opens after the combustion to release the exhaust gas from the chambers. Similarly to the intake camshaft and valves you can locate at the opposite side of the cylinder the exhaust camshaft and valves. Here is a photograph where hopefully, you will be able to identify the discussed parts. This is driven with a belt (known as cambelt) using the rotating crankshaft at the lower part of the engine. If you have a look at the end of the camshaft you will notice that it has a gear.
![ic engines videos ic engines videos](https://i.ytimg.com/vi/L0n-7c8Hp_0/hqdefault.jpg)
Of course, valves have springs to return to their original position when not pushed down. For better understanding here is a figure that demonstrates this. As you can see, this is controlled by intake camshaft which in real life looks more like this.Īs it rotates it forces some valves to open and others to remain closed. Now locate at the left of the image the intake valve. In fact, this is the swept volume of a cylinder multiplied by the total amount of cylinders. The cylinder’s displacement is what you commonly hear as a 3.2L, 3.200cc, 195.3ci in liters, cubic centimeters and cubic inches.
![ic engines videos ic engines videos](https://i.ytimg.com/vi/0x67uVtqFqw/maxresdefault.jpg)
What you can see at a glance is that this is a 4 cylinder engine.
![ic engines videos ic engines videos](https://i2.wp.com/electrek.co/wp-content/uploads/sites/3/2019/09/internal-combustion-engine-is-dead-e1568899410141.jpg)
With this in mind let’s have a look at the image below. That said, let’s start this… As a general unofficial rule, in internal combustion engines air (more specifically oxygen) + fuel = power. Warning: As you’ll see in future posts, the engine I’m discussing here has very little in common with the engines found in modern vehicles apart from the general operation principles. Here, I’ll try to demonstrate the simplest possible 4-stroke internal combustion engine in order to be understandable even by people with no prior knowledge. I’m posting this for future reference on more advanced concepts and redesigns of core components used in modern cars. So, first of all this post is extremely simple and I’m fairly sure that most people are already aware of these.