Hi guys,
I found this extremely amazing video of a high speed camera inside an engine cylinder. Since a lot of beginners don't know how their engines work, I thought I would post this. It looks like the engine is a 4 stroke because of the valves. For some reason, they don't show the complete cycle, but you get the idea.
http://www.youtube.com/watch?v=UvmBLqjaZxY
Enjoy!!!