I just have a comment on the usage of the word "suck" and the subsequent correction.. Sure, the atmosperic pressure is pushing in on the vacuum (or lower pressure area) created by the dropping piston, but our usage of the word "suck" typically implies active application of a vacuum (or lower pressure area) to move air or fluid. Based on your correction, you could just as easily say "NO.. You didn't really suck on that straw to drink Pepsi. You contracted the muscles of your mouth/throat to decrease the volume of your oral cavity, invoking Boyle's law. So actually, the higher atmospheric pressure "pushed" the Pepsi into your mouth.. so there". I agree that this device is not going to increase pressure enough to assist an engine, but your terminology correction didn't really bolster your argument much.. Engines, in our usage of the english language, suck.. Literally, not figuratively... well sometimes that too!! <img src="/forums/images/graemlins/smile.gif" alt="" /> As always, just my $.02.

JD