PIC controller for stirling engine

Hello, I'm a newbie here and am working on builing a Stirling engine for my university project. I was wondering if anyone has any previous experience on what should I be looking for. I need to program a pic controller to control the valves based on the piston positions which will require me to use position sensors. also i need to control the temperature and rpm of the system. And create a log of all the readings for as long as the system runs for later analysis.

Any idea on what would be the ideal PIC for this purpose? Any comments/ideas/recommendations would be really appreciated.

Thanks

There are no valves in a Stirling engine. It is a closed system with simple timing for the main cylinder and minor cylinder.

thanks colin55. i'm sorry for the confusion. I forgot to mention that the engine we are trying to make is based on the idea of stirling, its not entirely a stirling engine. We have changed the design of it quite a bit.

If you want to detect a particular instant in the cycle, use a Hall effect device and pick up the flux from a small magnet.

There are good sound reasons to have mechanically operated valves, I would suggest sticking to then.

thanks for the suggestion guys!