My mrs has asked me for some help, as she has to teach a group of 8-16 yr olds about how a internal combustion engine works.

One of my ideas is to get a cheap engine, and section it, so you can see inside it, and watch it working as you rotate the crank. I was hoping to do somthing like a zetec engine, as they are dirt cheap, and a nice simple example of a overhead cam petrol engine.

Just wondering if anyone has ever attempted somthing like this themselves, or have any tips on how to do a good job?

somthing like this is my aim at the end...