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vent line

7K views 7 replies 4 participants last post by  302 Z28 
#1 ·
I am going to use an RCI fuel cell (tank) as shown in the pic below in my '30 Ford coupe.

As I haven't used this style tank before, I have a question concerning the vent line routing.

The tank fitting for the vent line has a roll over shut-off valve already installed and a -8 AN fitting.

Do I install the vent line to the fitting and then down below the tank or should it be routed above the filler neck?

Would a couple of coils in the vent line be any advantage?

If the vent line is installed below the tank, will fuel run out the vent when the tank is full and gas sloshes around in the tank?
 

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#2 ·
Frisco - We run a RCI fuel cell on our circle track car and run our vent above the fill. Even though we do, I have seen many who vent below the tube and in a few instances below the cell. We personally run a one way PCV (metal) valve on a short piece of fuel line and then another line off of the PCV away from the cell and the driver. We have seen instances when a small piece of dirt has caused the safety valve check ball to leak in a roll over so we choose to run the PCV as extra insurance. The set ups that I have seen below the cell have employed the same PCV type of arrangement. They cut the PCV in off the top of the cell around 8" run the hose after the PCV up toward the fill tube height and back down under the cell. I don't see why that couldn't work out for your application too. Does the cell you plan on using have the foam? If it does a word of caution....after a couple of years, the older foam can deteriorate and wreak havoc with your fuel system if your not careful. The problem can be magnified if the foam is left dry for extended periods. Good luck with it and let me know how it works out for you.
 
#4 ·
I somewhat disagree with mounting it high.

Since a vent line only comes off the top, and there is no pickup tube, it really doesn't matter where you locate it. If you mount the hose outlet lower than the bottom of the tank, when you rollover nothing will come out anyways. Regardless of the valve.
One thing to remember. Its sucking air in, all the time the pump is pushing gas out. So be sure its CLEAN air going in, or your sucking dirt into your tank. I would filter the line with some small air filter. Less work for your fuel filter, and make your pump last longer.
 
#5 ·
Beenaway2long said:
I would filter the line with some small air filter.
Excellent suggestion. I will do that! :thumbup:

Thanks to you all for your replies. The use of a PCV in the vent line is interesting and something I haven't heard of before. I will check that out.

I will post what I end up doing and mention the results at a later date. I am hooking up the fuel lines today.

The tank I have does not have the foam inside. I considered using the foam to reduce sloshing, but the fact that the foam deteriorates over time concerned me so I opted to leave it out. I do have a cannister style filter mounted to the frame side rail near the rear of the frame. I will also install a small fuel filter in the line close to the carb.
 
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