rear gas tank vent hose question

[rockyrivermark]

1970 c10
350cu 350 auto short bed.
600 CFM carb

searched forum but didn't find my specific question there.

I have an aluminium rear gas tank with hardware, filler neck, and sender coming this week. through the bed filler with a marine type gas cap.

It has a 1/4" NPT fitting on the top of the tank for venting. I called the manufacture and asked how they recommend running a vent hose off that 1/4" NPT fitting.
they said most people just run rubber hose up under the bed with a loop in the hose but just open on that end.
Just seems odd to me to have open hose venting gas fumes.
Anyone have an tips or info on how they ran the vent line or is what they are saying even ok?
thanks!
Mark

[rockyrivermark]

For those who did the Rear gas tank conversion with a carb set up.
What did you do with the vent hole on top of the tank.
Hose to a Breather?
One way check valve?
Charcoal canister?
Just fuel hose pig tailed higher than tank?
Thanks for any info.
Mark

Originally Posted by rockyrivermark

1970 c10
350cu 350 auto short bed.
600 CFM carb

searched forum but didn't find my specific question there.

I have an aluminium rear gas tank with hardware, filler neck, and sender coming this week. through the bed filler with a marine type gas cap.

It has a 1/4" NPT fitting on the top of the tank for venting. I called the manufacture and asked how they recommend running a vent hose off that 1/4" NPT fitting.
they said most people just run rubber hose up under the bed with a loop in the hose but just open on that end.
Just seems odd to me to have open hose venting gas fumes.
Anyone have an tips or info on how they ran the vent line or is what they are saying even ok?
thanks!
Mark

[pappy 2]

this is what I did. Called a rollover valve I believe

[rockyrivermark]

Originally Posted by pappy 2

this is what I did. Called a rollover valve I believe

Thanks. So is that valve a one way vent also? Let air in but not out?

[Korted]

A rollover valve allows air/liquid both in and out of the tank until inverted (vehicle is upside-down), at which point a ball inside the valve covers the opening, keeping the gas in the tank. A rollover valve is typically installed in the tank as opposed to the end of a hose, so it is fixed relative to the vehicle. I ran a hose from the rollover valve up into the fender where my filler neck is, then "plugged" the end of the hose with a copper tube crimped almost closed. The tank can breathe, but it's not what I would consider "open to atmosphere".