Fuel filler Mods

[tarafied1]

Point is, I think the flap would cut down on splash against the actual cap, cutting down on any leakage that may be occuring. 

good point

I think the flap should be incorporated if feasible.

I'll see what I can do but it will make it much more complicated. I'll wait for warmer weather too to go junk yard hunting...

[sigtauenus]

I have a pop-open gas cap.  I think they're the bee's knees, but I've never been sure about how well they seal.  The new ones use a regular cap inside and the pop-open part is purely cosmetic.

Point is, I think the flap would cut down on splash against the actual cap, cutting down on any leakage that may be occuring.  I think the flap should be incorporated if feasible.

I wonder if it would be easier to attach a flapper valve at the bottom of the filler neck, ie, a flapper the full diameter of the filler neck, that would minimize fuel coming up the filler neck to begin with.  It could be set partially open for venting.  I mean, we're talking about large volume gasoline gushing up the filler tube, right, so anything to block the wave would work, and then the piece near the top of the tube should further keep anything that gets past from coming up.

I thought maybe some more plates welded in lower in the tube, with the holes drilled off-set to each other to create a series of baffles, but the holes would still need to be large enough to let full stream gasoline from the pump get past without backing up. 

Another option is a second plate with a larger hole and flapper valve could be tacked into place from the bottom of the tube.

No hard feelings if any or all of these are disregarded.  I know what its like to be working on a project and have the "good idea fairy" visit a ton of people who want to help out, especially when you are near the end and just about have it all figured out.

[tarafied1]

the biggest issue with flappers or baffles like you mension would be if it restricts filling flow. The nozzle is designed to auto shut-off if flow backs up. Baffles and flaps could cause the nozzle to keep shutting off. From reading the patents and design stuff the flap's main purpose was just that, to restrict flow so leaded fuel could not be pumped into an unleaded fuel car. PJ's suggestion of using one would help splash on the pop-open cap's seal when driving but does nothing for filling issues. Since I don't have an elaborate shop I am trying to keep it simple to make as well for reliability too. Aside from PJ's concern I think the one I just made for Pete will work good. My car has a repop pop open cap and I chose not to install the spring and seal and use a twist on gas cap so I don't have any issues with leaks when driving. It does help to have a few guys out there to give feedback under different conditions. We'll see what Pete says after he uses it, but I do appreciate the ideas. Keeps me thinking. So far a few guys on the Fix have some of the ones I've made now so that's kinda how I arrived where I'm at with it. When the gallery is up again I'll post some pics of Pete's that I made yesterday.

[apollard]

My car has a repop pop open cap and I chose not to install the spring and seal and use a twist on gas cap so I don't have any issues with leaks when driving.

Does the cap you use vent? If not, how do you handle normal venting (ie, when not filling)?

[tarafied1]

yes, it has a vent.

[Midlife]

Laurie asked me to ask you: will it come with a gas fairy?

[tarafied1]

 :scar I'm afraid to ask...
what's a

gas fairy?

[Midlife]

A gas fairy makes sure the tank is always full of gas, regardless of how much (or little) you've driven.

[tarafied1]

well that would take care of the problem entirely!

[Fast68back]

As long as the beotch doesn't spill it on the bumper

[tarafied1]

well if it's a fairy it could just magically appear in the tank!


Here is Pete's, first pic from inlet side with drain hole at bottom. 2nd pic is tank side and you can barely see the deflector that should prevent fuel from going back thru the drain hole. Last pic is the side view, you'll notice it's quite a bit different than a 67/68 shape which is pretty much an elbow.

[tarafied1]

Pete,
Did you get the filler neck yet?

[AzPete]

Got it tonight. Will install as soon as this rain passes which should be sometime Fri, Sat for sure.

[tarafied1]

cool, sorry it took so long but it should be a good one!

[AzPete]

No problem. If anything happens to quick in the Mustang world, one begins to wonder......

[AzPete]

Finally got around to installing the modified filler neck. Naturally, it went in with no problems.

Then, today I went to fill the car to see how it functioned. After checking the fit of the nozzle, I felt it might not work. It seemed that the modification kept the nozzle about 1-1.5 inches further out of the neck than I liked. In the past, the nozzle fit up to the rubber splash guard. So, I placed a towel below the neck to catch anything that might happen. I then pumped some gas slow. All looked well. Then, I went to full flow.....I put in 10 gallons like that. The auto shut off worked as it should and the amount is real close to what I figured I needed since my gauge is screwed. Upon shut off, I removed the nozzle and saw a bit of dampness about 1" down the neck and the fuel nozzle had dampness to match that position. No fuel escaped the neck at all.

On the way to the RV, I did a couple hard accelerations and then checked the inside of the cap for dampness. I could see dampness in the neck but no fuel seemed to reach the cap as it was still dry. Any fuel that got past the modification had drained back down thru the small drain hole.

All in all, I would say it works good. I will continue to monitor it and report if there are any problems.

Thanks tarafied1...............

[daveSanborn]

Then, I went to full flow.....I put in 10 gallons like that.

This statement alone speaks volumes.... I don't believe I've EVER been able to fill my tank at "full flow".

[Midlife]

Pete:
We'll need to check the anti-siphoning capability the next time you're over here...heh heh...

[AzPete]

Pete:
We'll need to check the anti-siphoning capability the next time you're over here...heh heh...

I have a ball bat that pretty much fixes that problem......

[sigtauenus]

This is all very good news.  I remember being very annoyed at never being able to use the auto shutoff feature.  All my other cars I set the auto shut off and then go check the oil and clean the windshield while the tank is filling.  Never could do that with the fastback.

On another note, has anybody seen the new '10 F-150 fuel cap design?  Or rather, the fact that there is no cap?  Just open the door and stick in the nozzle, no separate cap to remove.  Would be interesting to see how that is designed, and how quickly one can be found at a yard to play with.

[guruatbol]

It looks like you could use the F150 filler behind a pop open cap or in the trunk.....????  I'll have to see what I can find in a Yard.  Um, maybe there are other brands doing this.  I wonder which ones?  Did Ford try it out on the otehr brands first?  Like Lincoln?  Or one of their cars?

Mel

[sigtauenus]

Honestly, if the mod as-is works as well on a routine basis the way Pete described it, I'm going with the stock pop-open cap and the plunger seal vice the inner twist cap.  The F-150 would take this to a whole 'nother level.

[AtlantaSteve]

It looks like you could use the F150 filler behind a pop open cap or in the trunk.....????  I'll have to see what I can find in a Yard.  Um, maybe there are other brands doing this.  I wonder which ones?  Did Ford try it out on the otehr brands first?  Like Lincoln?  Or one of their cars?

Not sure if any of the brands outside the ford stable are doing it, but according to Ford:
Easy Fuel was introduced on the 2008 Ford Explorer and Mercury Mountaineer, and will be offered as standard equipment on the all-new 2009 Ford F-150, Ford Flex and Lincoln MKS.

I sat and stared at the picture til it dawned on me the flapper door seals tight against the body, those alleviating the need for a cap.  Since new cars are pressurized fuel-systems, I wondered how the heck they did that without a cap, then it dawned on me...the door IS the cap.

Since we need our tanks to vent, technically this would be no different than having a pop-open fuel door, with no cap behind it.  The Ford system has a flapper door that would keep splash back from being a problem during driving.  This would continue to be a problem on a classic mustang with no real cap.

[sigtauenus]

Hmm, didn't notice that, good eyes.

In regard to the classic mustang, if the fuel filler mod design here is sufficient to stop backsplash against the cap, then I see no need for the extra inner cap on the pop-open cap.

[Fast68back]

I fueled mine up again yesterday and I attempted about 80% nozzle. What I noticed was that with the pop open cap you have to keep the nozzle clocked to about the 5 or 7 O'clock positions since the cap is sitting on the bumper (on a gas station paper towel). It was flowing good, but when it was full it splashed before it shut off, spilling a little, a lot less than I used to spill.