Steam engine out of coke can help

[krelian1]

Hi, my first post. So brief presentation, I'm an undergraduate mechanical engineer student.
I hope this doesn't actually fall in homework, but it's a project that I have this semester: a steam engine car (small). I've made a bit of research and I ended up discovering the following "engine":
http://www.youtube.com/watch?v=brf0Ga0wnRc

Like in this video, I am provided with a soda can that acts as the boiler which has a nozzle attached to it and also pressure tested. As for the rest of the car and system, i am suppose to design it. But this steam engine is very inspiring. Anyone can explain me how this system is actually made? What I can't figure out is how the steam actually drives the piston inside. Also, is the valve necessary?

Thanks in advance =).

 

[jehan60188]

http://science.howstuffworks.com/transport/engines-equipment/steam1.htm this should point you in the right direction

 

[256bits]

Here is a double acting version of the u tube video

http://www.animatedengines.com/oscillatingsteam.html