Guest Post from my 12 yr old: The dummie’s guide to cars

Cars are those fantastic things on wheels that whiz around, transport us, and do many things for us.

But it is not just a structure which has an engine and moves around. If you look in deeper, you will find a series of complex machinery. A lot of maths, physics, chemistry, geometry and all go into making a car. Even your daily shopping roundabout. It is not just about looks or sound. If you ever met a real car tuner (not a ricer*), he/she would bore you with talk like,”This chevy camaro has a 4.5 L V8 in it, has an Edelbrock supercharger, Ohlins suspension, has a BMC air filter and an Armytrix exhaust system…” and yada, yada, yada. But to someone who loves cars (like me!), this would be a delight to talk about. If you’re not intrested, don’t read on, but if you are, let’s dwelve into the details.

* A ricer is a person who spends money on the looks of his car instead of upgrading & modifying the engine. They are also known to make the car look absolutely disgusting.

The engine

There are normally four types of engines:

  • V types
  • Straight/inline
  • Boxer/flat
  • Rotary

V type engines normally have their cylinders arranged in a 90 degree vee. They take in more fuel than inline engines but mostly have higher power outputs. One of the most common V types is the V8 engine with 8 cylinders.

Straight/inline engines have their cylinders arranged in a straight line. They can have either 2 or 4 valves per cylinder. They normally take in less fuel than V types, though they can still make ludicrous power outputs.

Boxer/flat engines have the cylinders arranged horizontally facing the outside. The pistons will also look like little steel fists boxing. This engine is also used in a legendary rally car, the Subaru impreza.

Rotary engines don’t have pistons at all; They have a rotor which revolves around a crankshaft. This engine is used in another legendary drifting car, the Mazda RX7.

Engines can also come as:

  • Naturally aspirated
  • Turbocharged
  • Supercharged

Naturally aspirated engines don’t have turbochargers or superchargers.

Turbochargers are small turbine-like things that force air into the cylinder more forcefully. The exhaust gases of the car drive the turbine in it, which in turn pushes the air forcefully into the cylinder.

Superchargers are similar to turbochargers except that they are powered by the engine itself, not the exhaust gases. There is a belt that connects to the crankshaft of the engine which drives the supercharger. Turbochargers are more efficient, but at the same time, are more dangerous.


Sizes are measured in cc (cubic centimeters). For example, a 1500 cc engine: height = 10 cm, width = 10 cm, length = 15 cm. 10 *10 *15 = 1500. Normally, a bigger engine means more cylinders. It does’nt have to be like that, though. For example, a Fiat 25 L engine having only 4 cylinders. 25 liters also means a whopping 25000 cc. What a waste of space.

Bore and stroke

The bore is the diameter of a cylinder in an engine. For example, if the bore is 3.7 cm, then the diameter of the cylinder is equal to 3.7 cm. Cylinders with a larger bore are used in performance engines, while the ones with smaller bores are used in heavy-duty engines, such as dump truck ones.

The stroke is the length of a cylinder. For example, if the stroke is 7 cm, that is the length of the cylinder and it is the distance between the cylinder top and the piston head if it is at the bottom. Engines with shorter strokes are used in performance vehicles. Engines with long strokes are used in heavy-duty vehicles.

Oversquare, undersquare and square engines

Oversquare engines have a larger bore and shorter stroke. These engines are used in performance vehicles. Undersquare engines have a smaller bore and longer stroke. These engines are used in heavy-duty vehicles. A square engine has an equal bore and stroke.

Two-stroke and four-stroke

Engines are also classified as two-stroke or four-stroke ones.

An engine is classified as a four-stroke if there are 4 kinds of strokes done by the pistons:

  1. Induction stroke
  2. Compression stroke
  3. Power stroke
  4. Exhaust stroke

(If a piston does all the strokes, it is called as a revolution.)

In the induction stroke, the piston moves down and the valves let in a mixture of fuel and air.

The compression stroke happens when the piston moves up and compresses the air and fuel mixture.

The power stroke happens when the spark plug ignites the fuel and air mixture, making it explode, pushing the piston down forcefully.

In the exhaust stroke, the piston moves up and pushes the exhaust gases out of the cylinder.

A two-stroke makes more power, more noise and pollutes more than a four-stroke. It is called a two-stroke because only two strokes from a piston complete the revolution. This is the revolution order:

  • First stroke = Induction & Compression
  • Second stroke = Power & Exhaust

Did’nt get it? I’ll explain in a simple way: what is special is that there are 2 kinds of strokes that get done simultaneously in one piston movement. So all strokes are done in only 2 movements of a piston. Special, is’nt it?

Power, torque and Jeremy Clarkson’s famous saying: POWERRR!!!!!!!!

You know Jeremy Clarkson, right? Do you? Anyway, he is quite famous for his saying: POWERRR!!!!! He says it’s supposed to increase the power of a car. You know what? Let’s ditch the claptrap.

I will put it in a simple way: Imagine there’s a wall. A car is going to crash into it. Bhp (brake horse-power) is how fast it will crash into the wall. Torque (nm) is how far the wall will get pushed from standstill. In other words, if there’s more power, the car will go faster. If there’s more torque, the car will accelerate faster. Imagine there is a titchy little car with an engine producing 1550 nm of torque. The axle would break because of so much force during acceleration. If the engine would make 900 bhp and only 30 nm, then the acceleration would be really sluggish, but it will slowly get faster and faster. That is power and torque.

How to take care of your engine

If you are going on a road trip, be sure to inspect your car and repair anything that needs to be repaired. These are the things you must do:

  • Check the engine oil. Replace the oil if it is impure or refill it if the level is low. Less or impure oil means less lubrication for the engine and gearbox.
  • Check the brake fluid. If the level is low, then refill it immediately. Less fluid means less braking power.
  • Check the steering fluid. If low, then refill the container. The hydraulics won’t work properly if the level is low.
  • Check the timing belt. Look closely for signs of wear, like cracks, thin spots, e.t.c. If seen, take it to your mechanic. To check if the timing belt is loose, look in the car manual and check the tension by pushing the belt with enough force until the written length, like 10 mm. If it goes beyond that, take the car to your mechanic. If the recommended length is’nt listed, then start up the engine and listen closely for slapping sounds. If that sound comes, then take it to your mechanic.
  • Refill coolant or antifreeze

These are musts if you want to go road-tripping.

Oh, and check the battery too.

After long periods of time:

  • Change sparkplugs
  • Change engine oil or refill
  • Refill coolant
  • Repair or replace timing belt
  • Don’t stress the engine

That’s it, people. There is a lot more to learn, but this is what you need to know for now. Happy driving!

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7 thoughts on “Guest Post from my 12 yr old: The dummie’s guide to cars

  1. Very informative post. Great job dear.
    Never quite understood the difference between Torque and Power till now. Thanks to you, now got that clear.
    Will take your advise, when planning to buy one 🙂

    P.S. Adding a few images / Videos will help imagining about what you write as well.

    Liked by 1 person

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