diaphragm engine and pump

[fullofhotair]

Could the diaphragm on an engine like Junkies latest video also have a dual purpose? Use the enclosed top of the diaphragm to make a diaphragm water pump. Could be used for irrigation and assist the engines cooling.

[Jerry]

Yes it can, but it I don't know how it would effect performance and efficiency, my belief is it would be adverse since the diaphragm normally operates against atmospheric pressure. Here is a video where a guy builds his own water pump from aluminum sheet, and attaches it to a T off the air tube going to his power piston. Similar to what you are asking, but your concept may have other advantages or disadvantages if you use the diaphragm directly. You can see the hook up about 4:40, and it in operation after that.
[youtube]http://www.youtube.com/watch?v=MZDr5clZ3HA[/youtube]