I think I have devised a simple solution to the leaking gas cap issue on these cars.

A bit of history..

I wanted to stop the fuel slosh/ exiting from the filler tube on my 64 dart; on hard R turns it deposits fuel dribbles down the quarter panel.

-Originally I was going to redesign the entire filler tube and put it inside the trunk for filling.

-Then after some research on the topic i bought one of the unleaded fuel door restrictors from PCI....





I didn't really care for that solution and was skeptical of the results as the fuel would still flow past the pci mechanism once installed in your filler tube... also it would not allow me to directly fill the car with race fuel when needed.


So I am testing another soultion/ Idea. So far it was worked with just a small modification to the gas cap, without affecting performance / emissions.

Here's whatcha Need:
Some 1/16" Thick Gasket paper - This stuff I have had around for ever and it's flexible but not stretchy.

approx 1/16" Thick..


I used the existing Rubber Gasket on the Gas Cap to make a template...
Cut the new Gasket material from the template and stuck it behind the OE Rubber Gasket... it makes for a super snug fit when the gasp is turned down on the filler neck / quarter panel.
Hopefully no more leaks down the 1/4 panel when driving on Hard R Turns with more than 1/8 Tank of fuel
(that flimsy cork/rubber gasket serves the same purpose -installed by previous owner(s))




I hope this can help someone out in the future.

Greg

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http://www.youtube.com/hyperpack

Gotta Full Tank of gas and Hitting Some twisties tomorrow on the way to a Mopar Show...

Will be reporting Back!

Greg

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http://www.youtube.com/hyperpack

Isn't it funny that Lee Petty moved his gas fill up the quarter for the race car!

I tried to get that deal into my Lancer and could not get it to fit or work.
I gave up.

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Hyper_pak

Hope it works. I played with gaskets of different thicknesses and stiffness and it did not work for me, but who knows? I may have had a leaky cap (metal part).

Lou

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Home of Slant6-powered fun machines

Greg,
Have you seen these? I am considering something for the fuel fill on my Belvedere as it fills behind the license plate.
https://www.classicindustries.com/product/tf700223.html
https://www.amazon.com/Danchuk-14949-Filler-Check-Valve/dp/B013V3861C
https://www.fillernecksupply.com/perko-fuel-filler-hose-anti-splash-back-check-valve-14981393-0635DP0/

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-MattMan
LEANED & MEAN

No matt I have not.. thanks for sharing.. will look into it.

Greg

_________________
http://www.youtube.com/hyperpack

Same here. The last gasket I tried was cut out of an old radiator hose, about 1/4" thick. It was so tight I had to use a pair of pliers to get it on the racecar. It helped, but it still dribbled a little on hard rights with a full tank. I figured it was a bent sealing surface on the fill tube.

We ended up dropping $1500 on an FIA-rated 22-gallon ATL fuel cell with a remote fill that we mounted up in the C-pillar for good measure. Lemons rules on fuel systems and fuel leaks are pretty strict, and they had noticed us dribbling a couple too many times by that point.

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing

We had black flag issues on our lemons car as well due to fuel leaking out the stock filler and we couldn't get it solved. We ended up with a rated fuel cell in the trunk as well although we are still fueling directly into the cell in the trunk which is a pain. Do you have any pictures of how you routed the remote filler for yours?

Hmmm. I am wondering if we pulled the filler neck out, built up some weld on the opening surface, then belt sanded it down to be flat, that might allow the gasket trick to work. I have seriously contemplated going to a cell in my 64 Dart street/track car to eliminate this problem, but there should be a way to do this with stock-ish stuff, since the cap is not vented and there is the big vent line from the top of the filler neck inside the trunk.

I have the billet Damraider cap, and that one should provide a wider/flat/rigid surface for sealing?

Lou

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Home of Slant6-powered fun machines

Here are the pictures I could find. We got our ATL cell and an ATL remote filler fitting from the Lemons store. Clear fill hose would be nice to help avoid overfilling, but we ended up using black reinforced hose because we couldn't find anything on short notice that was clear, fuel-safe, and wire-reinforced. The dashed lines in one picture are just me tracing where the interior C-pillar reinforcements were laid out so I could drill a hole between them.
https://i.imgur.com/7vSOE22.jpg
https://i.imgur.com/WkvGXVY.jpg
https://i.imgur.com/8DvNoZ0.jpg

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing

Lou, if you mean this cap, it leaked even worse than a stocker on the Lemons Dart with the O-ring that came on it. Adding a wide gasket of the same thickness would probably be better.

I'm sure there's a combination of parts that could get the job done without going the fuel cell route. A cap that seals better along with one of those check valves, or maybe a newer-style fill tube adapted from a modern car, would probably work. We just didn't have a choice on the Dart due to the rules of the series. It's either a 100% stock fuel system including filler neck, or an approved fuel cell. It seems arbitrary to me, but I know the tech inspectors are busy enough without having to judge every kludged fuel tank solution that comes through.

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing

How far would you have to jack up the right side of the car to test the cap for leaks?

Or how about a rotisserie ?

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

I think for a racing car the evr team solution us fine.

I am still testing my solution. Will report back soon.


Greg

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http://www.youtube.com/hyperpack

So a $24 check valve that would eliminate the problem is illegal? Making the only real option to be a $1500 cell. That make a lot of sense to me. Yep I know, you have to play by the rules.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

~ 1 g cornering or perhaps more at times, so 45 deg angle car jacked up to test properly.

Lou

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