No Subject

Having just read the posts on oil filled motors, I note that you loose some power, and they are messy, things that I never thought of.. the messy I dont mind, but the loosing power, I do mind.. for the auto-pressure compensation with the scuba reg, how exactally do you accomplish this.. where do you pipe in the pressure to operate the reg???? I just cannot picutre it in my head, although I think it is a very good idea...