I'd Rather Have Some Lamb Shawarma

To move a car, the wheels need to be rotated. fuel is burnt in the engine, and through gears and shafts, motion is transferred from the pistons to finally rotate the wheels.

We have learnt in school (in most cases) solids expand when exposed to heat. so does metal - in which engines are made of.

Let's have a short and simple revision on how does an engine convert energy in fuel into rotational motion.

Fuel is burnt/combusted in succession and that will result in the up and down movement of the pistons. this linear motion is then converted into circular motion by the crankshaft. this action is quite similar to cycling the pedals of a bicycle. simply, that's how an engine works.

As mentioned earlier, solids will expand when heat is applied. since fuel combustion produces heat , some form of cooling is needed to prevent the engine parts from expanding too much. we really don't want the engine to overheat. if, let's say the pistons expand too much, they will be jammed/stuck in the cylinder and put the engine to a halt.

A means of cooling down the engine is by allowing water or coolant fluid to pass through the engine construction. this will draw the heat away from the engine. the component responsible for this is the radiator.

As the fluid passes through the engine, it will take some of the heat away from the engine. it will then flow out of the engine hotter than when it entered. this hot fluid will then be cooled down by the fan or ram air (flow of air that you get when the car moves forward). there is a pump sumwhere to ensure continuous flow of fluid. this is how engine temperature is regulated.

Let's take a look at the path of water/coolant inside the engine. first, here's a simple construction of the engine.

Let's call these two parts head and block. cylindrical holes are made to make way for pistons to be fitted in. these holes are the space where fuel is burnt and piston heads reciprocate. you can call it combustion chamber or cylinder, if u like.

More holes are made inside the engine block and head. these are the channels where water/coolant flows in/out from/to the radiator. to make sure that ther'll be no leaks when all of these holes meet, a gasket is fixed in between block and head. the gasket is made of material softer than the block/head. when they're assembled together, the gasket will be sandwiched, deforms and comforms to the shape of block/head, hence forming a tight seal. now, water can flow through its channel, isolated from the combustion chamber.

In a long journey, the last thing that you want to know about your car is an empty/dried radiator. that is because of the nasty things that will happen when the engine overheats. however, if somehow the engine does overheat, there is still a little hope for you to continue your journey, provided that you don't do the don'ts.

When you find out that the temperature indicator on your dashboard shows an unusually high temperature, stop at the nearest place where you can find water. if the dial is way off the scale, just pull over and stop immediately. (be sure to be safe. try not to stay in the car, off the road. some drunk or sleepy driver might just crash his trailer into your car).

Wait for the engine to cool down before you open that radiator cap. not only because it's hot, but also because very hot steam and water might just gush out and injure you. you might wanna wait long enough for your engine to cool down before trying to add water and attempt to start the engine.

Here is the worst case scenario. due to overheat, engine parts expand more than usual. this might cause engine head to warp or bend, forming a gap in that head-gasket-block sandwich.

If the gap is there when the engine is started, instead of having an isolated flow, water from the radiatior might flow into the combustion chamber since the channels are no longer tightly sealed. when this happens, you're done. the engine needs an overhaul before it can function again. not only it will majorly affect your journey, it's gonna cost you a bomb for the overhaul too.

Water, essential to life. scientists have been searching extensively for its presence in Mars. yet, it is the last thing that you wanna find in the combustion chamber. so, before starting a long journey, do make sure that the radiator has water in it. if there are any faulty parts or leaks in the radiator, it is a much better idea to have it repaired than having the engine overhauled. seriously, it will cost you a bomb.

I'd rather buy a tablet PC with that cash, or give it to charity, or have some lamb shawarma (perhaps with cheese).