official term for sucking water in? That's a sweet valve. Basically it's like my idea but "reversed haha, didn't even think about the water creating that "seal" to creat a vacuum in the tube and open the valve. And I will add that a small amount of water isn't bad for an engine (small!), as it'd get burned up in the combustion process (evaporate since it isn't combustable), alot of boosted cars run a water injection kit that sprays a small amount of water (or sometimes alky/meth mix or any combination) to cool the heated intake charged from being compressed. It allows you to run more boost on pump gas while lowering the risk of detonation.