Fuel tank vents

[Duramax]

I have a question. How much venting is needed for a fuel tank like mine lets say? A 23 gallon tank, with a 2.5 260efi, Weldon 2005a fuel pump.

All I have in the tiny vent that is on the fuel cap, nothing else. That can't be enough, can it?

 

[Headless hula]

Whatever goes out, something has got to back in right? Mines a thru hull style, and has 1/2 or 5/8” line to it. It’s one of the flush style with the two little holes with screens.

 

[02HoWaRd26]

The displacement of return fuel needs an equal or greater ability to remove the air. I’d imagine anything less than 1/2 would be cause for issue and more chance of vapor lock.

 

[Ragged Edge]

The tiny vent in the fuel cap is all I had on my Stoker, heavily modified 2.5 260, Bosch fuel pump (I think is was the 044 but don't remember for sure) 30 gallon fuel tank. Never had any kind of issue with vapor lock or fuel delivery. It did vent some fuel on the top of the tank when full, annoyed me cause I'm a clean freak.

 

[stoker2001]

The tiny vent in the fuel cap is all I had on my Stoker, heavily modified 2.5 260, Bosch fuel pump (I think is was the 044 but don't remember for sure) 30 gallon fuel tank. Never had any kind of issue with vapor lock or fuel delivery. It did vent some fuel on the top of the tank when full, annoyed me cause I'm a clean freak.

Al stoker was talking about this very subject on facebook "stoker owners page".he said some types of his vented fuel caps were ok for venting and some weren't..

 

[Duramax]

The top picture is my new vent line. Like what was mentioned, I have 3 feet of line and ran it up into the existing lines up in the gunnel and zip tied it off. Second pic is just of my return lines. Some people asked if it went into my water separator. It does not.