So welcome to this lesson concerning the exterior parts of an engine. Now, before we go too far into the course, I just want to clarify that when I talk about petrol, I'm actually referring to gasoline. And the reason I say petrol is purely because I'm from the UK, I know a lot of people in the US and Canada will refer to it as gasoline, and that's fine. But just because I'm used to saying the word petrol, I'm going to keep referring to that throughout the course. And if you want, you can just change that in your own mind with the word gasoline. When I mentioned system pressures and temperatures, I tend to work in bar pressure and Celsius for temperature.

Where possible, I'll try to put some conversions on the screen if I do mention the pressures and temperatures, because I know for some people, they don't use metric units, they use Imperial. So it's always nice to see a straight conversion rather than try and have to work with units that you don't understand. Now that's out of the way. Let's Have a look at a 3d engine. This particular engine is a four stroke diesel engine. Throughout the course, we're going to be talking about the diesel engine only.

And then I'm going to clarify on the differences between a petrol and a diesel engine and give you some examples concerning petrol engines. The reason that I want to stick to only one type of fuel, at least initially when we start the course, is because if we start mixing engines and we start changing between diesel and petrol, etc, it gets quite confusing. So let's stick to diesel just for now. And at the end, I'll tell you some of the telltale signs you can look for to identify a petrol engine and also what some of the differences between petrol and diesel engines are. But let's stop there for a moment. And let's go and have a look at some engine components so we can see exactly what's happening inside an engine.

And then after that, we'll look at the two stroke engine and the fourth stroke engine. I'll explain to you exactly how they work. And by the time we've gone through that, you will definitely be in a position to look at this engine in a totally different light. And you'll understand how and why it's designed the way it is.