Fuel venting question

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Jun 20, 2014 | 10:31 AM

salf100

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Fuel venting question

So I'm thinking about making a custom fuel neck and cap for my stock gas tank on my 64. I understand our stock fuel caps are vented. Question is can I add a vent tube to the new neck I'm making and use a non vented cap. Will this suffice? I was going to have the vent tube exit through the floor near the line that goes to the pump. I'm making the new neck and cap from aluminum and plan on polishing it. Lastly any good sources for aluminum screw on caps and bungs?

Jun 20, 2014 | 01:30 PM

TA455HO

Lead Gopher

Joined: Aug 2012

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From: Seattle

The equalization with atmospheric pressure has to happen at a level higher than the gas in the tank. If you run a tube down below the level then when the gas expands not only will it run down and out your tube, but the flow, once it gets going, would act like a siphon and drain some of the tank wherever that tube is pointed. Might work, but you'd have to experiment.

Jun 20, 2014 | 08:13 PM

rusbukt

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Joined: Aug 2004

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From: Sacramento, CA.

If you looped the new vent tube up the filler hose( toward gas cap) then back down alongside fuel line and out you should be O.K.
Maybe use a zip-tie to keep vent tube in place.

Jun 21, 2014 | 01:58 AM

salf100

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Can I vent a cap by simply drilling a small hole in it? Maybe my crazy head is causing me to go through too much trouble!

Jun 21, 2014 | 04:47 AM

jowilker

Fleet Owner

Joined: Jun 1999

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From: Creedmoor, North Carolina

Quote:

Originally Posted by salf100

Can I vent a cap by simply drilling a small hole in it? Maybe my crazy head is causing me to go through too much trouble!

What's the issue, or cause of crazy head?

John

Jun 21, 2014 | 09:34 AM

rusbukt

Elder User

Joined: Aug 2004

Posts: 602

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From: Sacramento, CA.

Quote:

Originally Posted by salf100

Can I vent a cap by simply drilling a small hole in it? Maybe my crazy head is causing me to go through too much trouble!

Then everytime you make a right hand turn you'll have a stream of gas pissing out your drilled hole. The purpose of the vented cap is to allow the built-up vapor pressure to escape but stop the liquid from sloshing out.

Jun 21, 2014 | 10:15 AM

salf100

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As far as my head goes I'm the type to over think very project

Talking with a buddy last night and he commented I should just move my tank under the bed. It's a thought. But I like my idea better. I guess I'll keep looking for a vented cap.

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Jun 21, 2014 | 10:32 AM

hiball3985

Logistics Pro

Joined: Mar 2005

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From: tujunga, calif

Quote:

Originally Posted by salf100

As far as my head goes I'm the type to over think very project

Talking with a buddy last night and he commented I should just move my tank under the bed. It's a thought. But I like my idea better. I guess I'll keep looking for a vented cap.

There was another post recently about this and many on other car forums. The replacement caps that you can buy today only vent in on direction, they let air in but don't let pressure build up out. This is do to EPA regulation from 1971 from what I have read. I've tried a dozen different so called vented caps with no luck on my 57 Ranchero. I finally drilled a 1/8" hole in the cap as many others have also done. I like the idea of adding a vent to the filler tube and may do that some day when I'm not so lazy