Recently, I have come across a great website, which explains and shows in details the structure of most types of engines. I will try to retell the most important things in short. But first, I want to ask you a couple of questions.
Can you explain to your girlfriend the difference between a diesel and a gasoline engines? What is the difference between four and two stroke engines? No? Then I invite you to read this article.
Four stroke engine
The four stroke engine was first introduced by German engineer Nikolaus Otto in 1876, and it is also known as the Otto cycle from then on. But it is more correct to call it a four stroke cycle. This engine is probably one of the most common engine types of these days. It is used in almost all cars and trucks.