Filling a center fill fuel tank

[gilbert911]

Q: What would be the advise on preventing an over-fill / spillage of fuel when using a
4" dia center fill fuel tank neck?? - other than just a visual check.
Is there some sort of gauze that can be / should be fitted inside the neck to give a better guide /stop splashback
Something similar to that which is in a '72 oil tank ?

[NeunElf]

Many race cars seem to have a collar around the filler neck to catch overflow and presumably have it go down a pipe to some place safer than the bottom of the car's trunk.

What plans do you have for your car? My 356A has a center fill, no filler neck to speak of and a really wide filler diameter. That has never been a problem but it's only been filled in a leisurely fashion at gas stations. I don't think dumping five gallon cans into it at a racetrack would be a really good idea.

Come to think of it, my 1974 Land Rover Series III had a screen in the filler neck. That was probably intended to keep out the larger pieces of "chunky style" petrol at third world filling stations. I think there was also a sort of telescoping arrangement to extend the filler neck and make it easier to fill from cans, or maybe clay pots or folded banana leaves. All excellent features if you're way, way far away.

[Bobs 67S]

Gilbert, almost every car that I have known with the center fill has been equipped with a hunk of Black Forest Oak, commonly known as a "stick". It's very technical and has been the topic of just hours of detailed discussion.

They come in a verity of widths and most are long enough to not fall in. Some feature a wire loop handle. One was safety wired to the neck. Others have one gallon notches or steps to visually reference volume of the tank prior to the fill. One even has the chart for current volume and the corresponding fill volume to minimize heavy mathematics at a rushed pit stop....This is matched to the plastic fill cans with each gallon measure marked.

But all of this is predicated on that "first fill" - given gallon by gallon and very slowly within the last two of tank capacity to see just how accurate that 12 or 17 gallon tank is. Once max fill is determined...very large reminder markings are usually prominently displayed or given to everyone who could possibly lift a can or wrangle a filler hose.

As you can see use of the "stick" would rule out any screen blocking its use.

Hope you have a fun time determining your use and abuse of the center fill.


The next discussion is how to NOT drip fuel while retracting the hose or fill can- so you don't smell raw fuel in the car for the next 30 mile drive.....

[CamBiscuit]

Gilbert

Hope this helps...

Cheers

Cam

[CamBiscuit]

Found one more from an R Replica down here...

[Neunelfer]

The 914 shield I have (which Cam posted in post #4) simply unbolts from the top of the tank. Good luck getting at the 7 or 8mm fasteners but, it may come in handy.

There's an overfill pipe that exits out around the 11:00 position and drains (factory mind you) to, heaven forbid... THE GROUND!

Cam, that's the seond time you've posted my filler You can still see the cut measurements for the fiberglass lid on the cowl...

[CamBiscuit]

Eric

Love your work

[JohnT]

that these are difficult to fill with a California gas pump because the big neck is unable to deal with the evaporative controls connected to the nozzle. On the up side, my fuel cell is 17 gallons and I rarely put more than 10 in (it's a 30 minute race and I don't need the extra weight). The other reason we rarely fill the cell all the way to the neck is that the sponge blocks aren't set up for really full tanks and there is a lot of wastage that will come from fuel sloshing about and spilling out the vent.

In other words I guess what I'm saying is that we never ever fill the tank which is how we avoid the filling issues.

sorry

johnt

[2POINT7]

I am doing fuel through the hood on my '58A project. This photo, shot 2 days ago, shows a technique for locating the center of the cap with a plumb bob just prior to replacing the hood for precise location of the hole to be drilled.

Kind of an interesting process.

[andyjboy]

What an excellent idea !!