This is an awesome calculator for a bunch of things:
Unit conversion
Performance prediction
Engine geometry
Gearing
VE approximation
Power plot
Power estimation
Camshafts
Intake Tuning

Found here: http://www.opeltuners.com/niklasj/CIH_numbercrunch.XLS

Just thought I'd share it with everyone. It's easy to use.

Enjoy!

Might want to mention it's a Microsoft Excel spreadsheet and I'm sure not everybody here has that installed. Because if you don't it won't work. Also... watch out for a macro virus. You never know.