In Tank FI Pump Solutions?

[Max Welton]

I am reviving a project I suspended in 2016 ... relocating my Megasquirt running gear from a 1968 Squareback to a 1967 Type-3 Fastback. In the 68 I just used the stock FI tank and mounted an airtek pump on the beam. The 67 tank is of course not set up for FI. But I very much like the filler inside the frunk and the tank itself is in excellent condition.

I would like to explore in-tank pump solutions. I am not averse to redesigning the bottom of my tank. I have seen weld-on fuel tank sumps and wonder if something similar could be done to place a submerged pump in the bottom of the tank.

Ideas?

Max

[Max Welton]

So I'm finally getting back to this project. I have run two new fuel lines along the floor in the corner next to the tunnel. They front exit just above the napoleons hat on the right (passenger) side.

Most of the generic in-tank kits I am finding install from the top of the tank. This would be pretty inconvenient on this car and would require routing the fuel lines around the exterior of the tank. I'd like to do something on the bottom of the tank.

The stock 67 tank has a shallow ( ~5 inch wide ) depression around the fitting situated at the bottom of a slight "V" in the tank. That doesn't seem enough to be an adequate reservoir for the pickup.

My thinking at the moment is to cut a panel from that big flat area, create a flange on the perimeter to reattach the panel and build what I need to hold a pump and provide a reservoir on the inside (top) of the panel. The panel would reattach with small bolts through the flange with a fuel resistance sealant in between.

This approach should put most of the new hardware inside the tank making it easier to avoid interference with tie rods and such.

Thoughts?

Max

[Chip Birks]

So I'm finally getting back to this project. I have run two new fuel lines along the floor in the corner next to the tunnel. They front exit just above the napoleons hat on the right (passenger) side.

Most of the generic in-tank kits I am finding install from the top of the tank. This would be pretty inconvenient on this car and would require routing the fuel lines around the exterior of the tank. I'd like to do something on the bottom of the tank.

The stock 67 tank has a shallow ( ~5 inch wide ) depression around the fitting situated at the bottom of a slight "V" in the tank. That doesn't seem enough to be an adequate reservoir for the pickup.

My thinking at the moment is to cut a panel from that big flat area, create a flange on the perimeter to reattach the panel and build what I need to hold a pump and provide a reservoir on the inside (top) of the panel. The panel would reattach with small bolts through the flange with a fuel resistance sealant in between.

This approach should put most of the new hardware inside the tank making it easier to avoid interference with tie rods and such.

Thoughts?

Max

Top mount is pretty much the industry standard for in tank solutions. Granted most of them are designed to be somewhat serviceable, with different access panels and such. You could still do a top mount with lines inside the tank that are connected to the bottom. Use a nice big access panel on top that you can put your arm into with a wrench to tighten the fitting. That would eliminate the need for top exiting lines. Now that I think this through, it's probably what I should have done when I did mine

[Max Welton]

So I'm just back from talking to my fabricator and he's down for either a top or bottom approach. He also said that some (most? ) top-loaders incorporate a sender. And he isn't scared by the idea of modifying the top to accommodate a (presumably) larger device.

Coming in from the top I will still need to provide a decent reservoir for the pickup. Right now I'm leaning towards the bottom access panel option. But not heavily.

Ray, can you show me what you did? Got pictures?

Max

[Max Welton]

I've been thinking about how best to create a fuel reservoir and a friend pointed out this product from Holley. Anybody tried this stuff?

https://www.holley.com/products/fuel_sy ... hydramats/

Max

[Max Welton]

I asked about mounting the Holley 12-130 kit to the bottom of the tank upside-down.

I plan to mount this product on the bottom of my tank and fabricate my own bracket to place the pump and intake in the correct position. This means the mounting assembly will be upside-down and submerged all the time. Do you foresee any problems with this approach?

The answer:

The biggest problem would be sealing the module with the tank in an upside down position. During an normal installation from top down, the gasket will seal, but does not have the constant pressure and weight of the fuel in the tank. We would not recommend mounting the module up through the bottom of your tank.

The Holley Hydramat product really seems just the thing for the in-tank pickup, But if I want an in-tank pump I still need a way to present the fittings under the tank.

Max

[Chip Birks]

I've been thinking about how best to create a fuel reservoir and a friend pointed out this product from Holley. Anybody tried this stuff?

https://www.holley.com/products/fuel_sy ... hydramats/

Max

Those look super cool! Big $$$ though!

[Max Welton]

True on both counts. Still might be worth it.

So the problem with Holleys "hat" is that it isn't meant to seal under light fluid pressure. Maybe I can make my own.

How big around are the CB sump plates? Maybe I could start with one of those. My recollection is that CB made them bigger than stock.

Max

[risk]

Have you seen the aeromotive sump that puts the pump in the bottom?



Maybe you could fab up your own version of this?

Here's a cheap access panel too..



https://www.fueltankparts.com/6-od-bolt ... plate.html

[Max Welton]

That clear-out plate looks interesting. Also interesting is the note at the end of the product description.

This product is for use on the top of tank only.

I'm starting to think these companies are just liability averse and in some cases it would work just fine on the bottom. I understand that of course. But I think at a depth of 7-8 inches we're talking about less than 1 psi when the tank is full.

Max

[Max Welton]

Finally getting back to this.

Before putting a hole in the bottom of my original tank I'm testing the ability of the pump to seal upside-down and with a bit of pressure on it. Yesterday I mounted the pump in the bottom of a paint can and filled the can with gas. The can is about the same depth as the og tank so column pressure should be equivalent.

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It has been hanging like that since yesterday. No leak. Later I plan to clamp the lid and apply a few psi of pressure through a hole in the lid. If it still doesn't leak I am inclined to call it good.

Max

[Max Welton]

No leak overnight. Today I 1/2 emptied the can and installed a Schrader valve and put a few psi on with a bicycle pump. Let's see how long it maintains pressure without leaking.

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Max

[Max Welton]

Moving forward. I welded up the stock fuel outlet and drilled a hole for the Holley cover plate.

Once I work out where to clock the cover I'll modify the in-tank bracket to put the pump itself in the correct orientation with the pickup on the bottom of the tank.

[Chip Birks]

This is cool. Sure simpler that mine for inlet and outlet orientation. Can't wait to see how it turns out in the end.

[Max Welton]

Now thinking about fuel line fittings. The steel line presenting from the chassis is 1/4" and the pump plate are female 1/4" NPT. Because the cover is above where the lines exit the chassis a 90 degree fitting may make sense coming out of the 1/4" NPTs. That should make the soft-line route a little straighter.

But I'm also thinking about using quick-disconnects of some kind between the tank and the chassis and also between the chassis and the engine. Any tips or recommendations?

Max