[leeklm]

Nice write-up! While I did not use electric, I just upgraded my system with 1/2" using a RobMC pickup and RobMC mechanical pump w/return. Looks to be very good quality items.

[ta man]

Originally Posted by HWYSTR455

So I've heard some talk about how they have issues with RobbMC pickups sucking air once below a half a tank. To check this, I measured the tank depth, then the RobbMC pickup, and compared to the OE pickup.

When I installed the OE pickup originally, I cut the sock away from the plastic mounting nipple, and didn't just jerk the whole nipple off. That is shaped like a 'fork', and in the picks, you can't see that fork. But, as a comparison, the OE pickup is a 1/4" longer than the RobbMC pickup. Without the nipple, both pickups would be the same, fyi.

I originally purchased fuel cell pickup line, with the intention of extending the pickup, but decided I would just live with it, since I don't feel a 1/4" is going to make that big of a difference.

FYI - The fuel gauge in the car is aftermarket, and required swapping the sending unit, which was no problem, the RobbMC sender is mounted with screw brackets.

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If you go to the dragstrip make sure you have over half a tank of fuel with full traction.

[HWYSTR455]

Originally Posted by leeklm

Nice write-up! While I did not use electric, I just upgraded my system with 1/2" using a RobMC pickup and RobMC mechanical pump w/return. Looks to be very good quality items.

I'd be very interested in your results/performance. I've heard mixed reports of folks with that setup.

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[HWYSTR455]

Originally Posted by ta man

If you go to the dragstrip make sure you have over half a tank of fuel with full traction.

That's what I hear, but I tell ya, it's only like 2/3" max from the floor of the tank, and the sender arm drops to empty right at the top of the line. I can't imagine it needing a half a tank, it would be maybe like 2-3 gal left before it uncovers, sitting still anyway. I guess to be safe a half tank, but I will test it.

The OE one was like a 1/4" lower, and it would suck down to like max 2 gal (when driving). When I dropped it, I used the electric to get the gas out, via the OE lines and sender. There's less than a gallon in it if I had to guess. It's not much. (that was sitting still)

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[HWYSTR455]

One thing I didn't comment on, the feed line to the carb. If you notice, there's a 90 elbow on the feed side of the regulator that points down. This is intentional, and am going to use a swivel 90 degree fitting off there, which will allow some adjustment to line up with the dual feed line on the carb. Will also allow for engine movement without binding, like it will provide some slack.

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[leeklm]

Originally Posted by HWYSTR455

I'd be very interested in your results/performance. I've heard mixed reports of folks with that setup.

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I am curious, what were the concerns? I am running 1/2" up to the pump, then 3/8" to the qjet. 1/4" return line from the pump. Engine should be around 500hp & 575-600tq.

Regarding the RobbMC pickup, would it work to just extend the pickup with a length of 1/2" fuel line? I am picturing the rubber line just long enough so that it is lying on the bottom of the tank.

[HWYSTR455]

Originally Posted by leeklm

I am curious, what were the concerns? I am running 1/2" up to the pump, then 3/8" to the qjet. 1/4" return line from the pump. Engine should be around 500hp & 575-600tq.

Regarding the RobbMC pickup, would it work to just extend the pickup with a length of 1/2" fuel line? I am picturing the rubber line just long enough so that it is lying on the bottom of the tank.

Some are having delivery issues with that setup, and to get past the problem, some are adding electric pusher pumps. Then I hear folks who have no issues, so I wonder what the differences are?

Yeah, adding a line to the pickup was my thought too, which is why I bought the short length of fuel cell line. Can't use regular fuel line, it's not rated to be submersed in fuel. I even thought of putting a short length of hard line in the end and squashing it into an oval shape to get even lower. But like I said, it wasn't enough of a distance for me to feel it was worth the effort, or make enough of a difference. If it's too long, might even curve up, making it worse, or might even suck onto a surface. So I just left it as is.

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[leeklm]

"Can't use regular fuel line, it's not rated to be submersed in fuel"

I suppose that is true, but have done it in the past without issue. After all, the inside of the line is submersed in fuel. Of course the longest it had to last in my case was 3 or 4 years. Not sure how the next owner did... He might be still stranded on the road somewhere with a plugged fuel system.

On edit, here is a note from RobbMC on the topic...

You can try if you'd like but we don't recommend it for several reasons. First, a lot of fuel hose doesn't last very long when submerged in gasoline. Second, if the end of the hose is too close to the bottom of the tank, vacuum can cause it to suck to the bottom of the tank and stop flowing all together. Third, because the tank slopes up towards the back, a rubber hose can kink, especially as the hose softens after being submerged in gasoline for awhile.

When we designed the pickup tube, we tried to put it in the best possible position that did not require modifying the tank. Our units will pick up fuel as well or better than the stock unit, especially under acceleration.

[ta man]

Originally Posted by HWYSTR455

That's what I hear, but I tell ya, it's only like 2/3" max from the floor of the tank, and the sender arm drops to empty right at the top of the line. I can't imagine it needing a half a tank, it would be maybe like 2-3 gal left before it uncovers, sitting still anyway. I guess to be safe a half tank, but I will test it.

The OE one was like a 1/4" lower, and it would suck down to like max 2 gal (when driving). When I dropped it, I used the electric to get the gas out, via the OE lines and sender. There's less than a gallon in it if I had to guess. It's not much. (that was sitting still)

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You have to think what happens when the car is fully hooked up from a standstill...the fuel rushes to the back and will curl up,I know from experience with mine...I don't like seeing the gauge go under 1/2 tank at the track or it gets uncovered!

[jonmachota78]

Nice write up!

Thought id share a couple pix of mine since it's a very similar setup.

[HWYSTR455]

Originally Posted by jonmachota78

Nice write up!

Thought id share a couple pix of mine since it's a very similar setup.

Wow you have a ton of room back there! What body style is that? F-body?

Have a pic of the bracket you used to mount the pump?

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[jonmachota78]

Yes, '78 bird.
Here's an old pic before i redid i few things, but the pump bracket is the same. I just bent a piece of sheet steel and bolted it to the trunk floor. I wasnt crazy about drilling my trunk, but it happened anyway.
From the pix it looks like the pump hangs down a bunch, but when the car is flat on the ground and not on jackstands the bottom of the pump is just barely below the bottom of the tank. You cant see it from behind unless your head is on the ground right behind the car.

[HWYSTR455]

Yup, that's what I thought I was going to have to do, use a plate bolted to the trunk floor, had the plate ready and everything. When I got under there and started checking possible locations, saw I could snake it in on the strap and was happy.

Think I will still make a plate, and hang it off the tank strap bolt, and use the existing plate to anchor the bottom. Or something like that. I figure it might be a more permanent/stable bracket, but for now it's good enough.

Someone was saying they made a straight, flat piece, bolted it to both tank strap bolts, and hung the pump and a filter off of it. Hopefully will see a pic of that too.

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[HWYSTR455]

Here it is, the guy posted it, and says he's going to paint and make it look a little better. But gives you an idea.

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[Billz428]

Great Pix and write up !!!!

[Cerberus]

I am looking at a similar set up for my 72 GTO. can you provide parts supplier information and recommend a good flaring tool?

Also - is this a concern (from a parts supplier website):
The main issue when dealing with aluminum tubing (or any aluminum for that matter) is that it “work hardens” when it flexes, which can lead to cracks. It is important that the hard line is isolated from vibration and movement.

Clamp the tubing securely with rubber coated clamps (Adel clamps) and use bulkhead fittings where the tubing attaches to the flex line. Never run the tubing directly to the engine without a flexible hose section. If installed properly, aluminum tubing is safe and durable.


Thanks!

[HWYSTR455]

Originally Posted by Cerberus

I am looking at a similar set up for my 72 GTO. can you provide parts supplier information and recommend a good flaring tool?

Also - is this a concern (from a parts supplier website):
The main issue when dealing with aluminum tubing (or any aluminum for that matter) is that it “work hardens” when it flexes, which can lead to cracks. It is important that the hard line is isolated from vibration and movement.

Clamp the tubing securely with rubber coated clamps (Adel clamps) and use bulkhead fittings where the tubing attaches to the flex line. Never run the tubing directly to the engine without a flexible hose section. If installed properly, aluminum tubing is safe and durable.


Thanks!

AN flares are 37 degrees, so any 37 degree flaring tool would work, the cheaper ones you have to be more careful with, the better ones work easier. Prepare the ends correctly before flaring, like gently file after cutting and taking the ridge out, typical tubing stuff. There's how-to stuff out there.

I have a Ridgid flaring tool, wasn't cheap, and they are more now. But I had planned on doing a lot of flaring, so bought a nice one.

And yeah, aluminum, have to use common sense when using it. Definitely don't want to run it to the engine, have to use soft lines for that. Don't want to ridgedly fix the lines to the chassis, the clamps should be a little loose around the lines so they move freely when the chassis flexes. The longest runs are lengthwise, so there's not much flex in that direction (it's more twist).

Should also use like 'bows' for some runs too. If you look at the run from the regulator to the first clamp on the frame rail, you see kind of a bow in the line, so it doesn't stress the fittings on the regulator. The clamp on the AC box should help isolate that too, from the fittings on the regulator. The body moves separately from the chassis, keep in mind.

There are examples and tech articles you can search that give advise on hard line routing, Aeroquip has some too. A quick browse of the pictures of examples is good reading.

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[HWYSTR455]

Some info from another thread about safety switches:

3 kinds of fuel pump safety switches, oil psi, tach signal, and inertia. The best ones to use are inertia, and pretty easy to wire. You can junk yard one off a newer car, or buy a new replacement one from an auto parts store.

(examples, can shop for better prices)

Ford Inertia Switch:

http://www.ebay.com/itm/Ford-Inertia...d11f86&vxp=mtr

Oil PSI:

http://www.ebay.com/itm/JEGS-Perform...e1cb88&vxp=mtr

Tach Signal:

http://www.ebay.com/itm/12v-Electric...ad630d&vxp=mtr


Oh, there's a roll over type switch too.
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[HWYSTR455]

I noticed those links for the switches I posted are no longer valid, so here's corrected info:

Summit Racing Inertia Switch # 890145 :

http://www.summitracing.com/parts/sum-890145/overview/

Pigtail/Connect Pico Wiring # 5756PT :

http://www.summitracing.com/parts/pco-5756pt/overview/

Painless Performance Fuel Safety Rollover Switch # 80160 :

http://www.summitracing.com/parts/prf-80160/overview/

You can search for the tach/coil signal ones and the oil psi ones if you choose, but the two listed above are far superior.

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[Skip Fix]

The new Holley pumps can be mounted sideways and would fit good back there. I've had good luck with my Mallory eventhough it is not mounted below the tank.