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Tech Information => Technical Discussion => Topic started by: Jack Gifford on November 01, 2017, 10:57:53 PM



Title: Fuel vent
Post by: Jack Gifford on November 01, 2017, 10:57:53 PM
I already have tip-over protection on my lakester's fuel tank (alcohol). But I'm adding a tiny tank (from a string trimmer) for onboard gasoline priming of a cold engine. Will it need its own tip-over-style vent?


Title: Re: Fuel vent
Post by: SPARKY on November 02, 2017, 12:03:30 AM
If I were inspecting I would say yes


Title: Re: Fuel vent
Post by: jimmy six on November 02, 2017, 12:11:04 AM
If you ended up on your side or top and some fuel leaked out and it caught fire.....would you want one then?


Title: Re: Fuel vent
Post by: kiwi belly tank on November 02, 2017, 09:11:48 AM
LOL! :-D :cheers:
  Sid.


Title: Re: Fuel vent
Post by: Jack Gifford on November 02, 2017, 11:11:17 PM
Okay, I agree that I want the protection. Could a home-built device be allowed if it's demonstrated to function correctly? I ask because a commercially available one (as on my fuel tank) is almost as large as the complete primer tank (1.5 cups of gasoline).


Title: Re: Fuel vent
Post by: Milwaukee Midget on November 02, 2017, 11:47:43 PM
Jack, you could go with an in-line vent, and it could then be installed just about anywhere you could run the line that vented outside of the vehicle.  Mine's got a little buna flapper in it, so I don't know how it would hold up to alcohol, but I just bulkheaded it to the floor of the trunk of the Midget.

I'm redoing my tank for EFI - if you want my old one, drop me a PM with your address, and it's yours.


Title: Re: Fuel vent
Post by: SPARKY on November 03, 2017, 10:26:55 AM
Vent hose from one corner diagionaly across the the tank so that it sticks down below the bottom and held so that it can't flop over if overturned ---NO loops


Title: Re: Fuel vent
Post by: Jack Gifford on November 03, 2017, 11:47:28 PM
Thanks for all the help. But, once again, I feel foolish... it turns out that the string trimmer tank already HAS a little valve built into its cap!  :-D And it works very well- with gas in the tank I turned it upside down, shook it around, tipped it 30 degrees all directions, and only got two drops out of it. And, no, the vent isn't clogged- it works fine when right-side-up.


Title: Re: Fuel vent
Post by: jimmy six on November 12, 2017, 07:15:58 PM
Jack, not being the devils advocate but with the tank installed in your race vehicle and you telling an inspector, even me, that you have tested it in all directions with fuel in it and nonE leaked out it would be tough for me to accept. It's not that I don't believe you but the association needs to be skeptical or some really bad things could get by.
If the cap on the tank is doing all the work for the roll over protection I'd build a device that accepted it, probably made of PVC pipe with a fitting and a hand pump of some kind, either vacuum or pressure, and proves it work off the car. Even putting a liquid in the pipe would be good enough for me. JD.


Title: Re: Fuel vent
Post by: Jack Gifford on November 12, 2017, 11:21:23 PM
It would take me about a minute to remove the unit (tank/shutoff/fittings- 2 mount bolts) from the car to demonstrate it.

My main concern will be to assure that it's within the mechanical protection of the roll cage- since it's high on the engine beside the Hilborn 4-port.


Title: Re: Fuel vent
Post by: wobblywalrus on November 13, 2017, 08:42:42 PM
What about venting both tanks with the tip over valve you have? 


Title: Re: Fuel vent
Post by: Jack Gifford on November 14, 2017, 12:08:40 AM
That's a good alternative.