Hydrogen tends to pool at the top of a vacant air space while oxygen being much heavier settles to the bottom. This has the effect of causing the mixture at times to be mostly hydrogen with gulps of oxygen as the unit is bounced around going down the highway. To prevent this potentially destructive situation that can harm valves and pistons I've installed a small vent to the bottom of this unit to allow engine vacuum to draw in some outside air that will travel in up from the bottom and mix the hydrogen/oxygen as it flows into the air space at the top. The arrow shows the vent I installed. The clear tube I attached goes up to the top past the water level so water can't drain out once the engine is turned off. I used aquarium air tubing and an aquarium air stone to filter the air as it is drawn in.

Previous Picture

Next Picture