Engine and Transmission Tech

The return is plumbed to the original pickup tube, so with a stick I should be able to bend that to direct it wherever I'd like within reason. Pointing it towards the mat would probably be a good thing to do.

Jim

Oh, I'm getting mixed up I think. The fitting you put in the sending unit is for the Roadmaster I'll bet? 😊

Anxious to see your progress on this.

Ordinarily Scott, that should be correct. However, the BBB crowd assures me that a 5/16" line is inadequate for any section of fuel line for this engine, with this carb. Add to that the large size of the Bosch 44 pump inlet, and a new plan is needed.

Currently I intend to pop a hole in the bottom of the tank on the RM and install a #8 AN fitting with 1/2" line to the pump inlet. More details when I have more parts, but I'm leaning towards a #8 banjo fitting. Carl's 3/8" supply line will stay, the line from the FPR to the carb will be increased to 3/8" and a 5/16" return line will be added. (The pump dead-heads at over 70 psi so a return will be necessary.) Redundant filters will be removed, and line pressure will be increased to 7 psi.

It could be confusing because I'm doing both my '71 and the RM, nearly at the same time. The '71 gets the tank mat, an internal hose, and a bulkhead fitting on the side of the tank, whereas the RM will get a fitting on the tank bottom and an external pre-filter. Both with Bosch 44 clone fuel pumps. The tank mat is expected to allow the single external pump system to work with EFI.

I suspect the 15" x 15" cross tank mat (part #16-100) would be a good selection for an unbaffled tank with the drain coming through the bottom of the tank. It would take some special fittings to do it (probably custom made) but if that mat was flipped upside down and a banjo fitting used in the rear drain location, arms positioned in line with the car, that could give the best orientation for dealing with slosh. I sort of wish I'd used that one instead of the one I got.

Jim

Sounds good Jim. I wonder if there is an unbaffled tank without that big vapor canister thing that doesn't have the original supply line spot welded to the bottom center of the tank and uses the late sending unit with the built in supply line? If such a thing exists it would seem that would be the easiest tank to use for this.

I have an early tank with no baffles and no big canister thing in the middle either. I can't tell you if the pickup is spot welded to the bottom, but even if it is, just move the holley fuel mat off to the side so an inside corner of the cross is sitting right next to what will be the return fuel line. No, it won't be 1 inch away from the fuel pickup but it's still dumping out right onto the center of the mat.

I would attach a right angle fitting to the fuel mat then put a hose barb on it. I would attach an overly long rubber hose to that right angle fitting, and then zip tie/attach a magnet to the middle of that hose.

Slide the end of the mat with the fuel fitting in first and push it far back into the tank. Let the magnet attached to the hose attach to the tank towards the back (bumper) of the tank then slide the hose over the pickup in the late sender and hose clamp it on. The pickup attached to the late sender is facing down and towards the gauge float. Perhaps bend it so it's facing a little more towards the back of the car?

The magnet attached to the hose will keep the hose from moving around and messing with the fuel gauge sender.

Does it need to be harder than this?

That sounds pretty good. Your engine will determine if a 5/16" pickup line is adequate. In both cases I'm working on it is not. (Keep in mind when working with these lines that the area of the tube ID is quadrupled when you double the diameter.) The line needs to be bent so that the hose will not interfere with the float. I'm using a 30" internal hose which will essentially go from corner to corner. The magnet along the hose is a nice touch but I think the fitting to the mat should be kept as low as possible in order to keep the mat as flat against the bottom of the tank as possible. I've ordered a banjo fitting to do that, allowing the hose to come off directly above the mat fitting. Also, the bottom rib that runs between the two round drain locations is a perfect location for one of the mat arms, provided the old pickup does not interfere. I would try to center the 15x15 mat on the rear of those round spots.

I had not heard about the pickup tube being spot welded to the tank bottom but I will check that out a bit later, probably today. It should be possible to position the mat to avoid it.

Jim

So here we go with putting the tank mat in the tank. First a 3/8 x 1-1/2" pipe nipple drilled for a banjo fitting:


Plus the banjo, copper washers and hex cap:


Attached and ready to go in the tank, with the bulkhead fitting in position:


And in place inside the tank after a good deal of pushing and pulling:


Should have drilled the bulkhead for the banjo first, more on that next time.

Jim

Looks like you positioned the mat towards the back (bumper) end of the tank as opposed to the front (axle) end of the tank?

Correct. Fuel slosh will be towards the rear under acceleration. Note the location of the stock pickup, and one of the short arms going forward from that point about 3 inches. That is in the center channel and should pick up fuel at cruise better than the stock pickup. On cornering or acceleration it should be MUCH better than the stock pickup. But you can see why I felt the 15 x 15" "X" would be a better choice.

Finishing the install today, more photos to follow.

Jim

Would 15x15 even fit with the existing fuel pick up welded to the middle?

You could always put 2 of the crosses in and plumb them together. :)

Quote:

Fuel slosh will be towards the rear under acceleration.

So? If you are that low on fuel you shouldn't be accelerating, you should be light footin' it! ;)



Edited 1 time(s). Last edit at 10/29/2022 05:18PM by MGBV8.

So first I shoved a short piece of rubber tubing into the bulkhead, with a wire tie threaded through it so I could pull it back out. This was to keep chips out of the line. When I cross drilled the fitting the drill made short work of the wire tie:


Here's how it looked just before deburring and clean-up.


...but there was enough left that with a strong set of forceps and some WD40 I got the plug out.


Finally, I was able to assemble the banjo and run the suction line to the pump.


That left wiring the pump, for which I used a DelCity Deutsch compatible rough service 2 pin connector which worked very nicely. I recommend the DC service kit, it costs $100 but has a whole bunch of connectors. Dan bought one and this is the first time either of us had had occasion to use it, and it worked well.

I still have to relocate the inertia switch. I expect to reuse the Ford switch I have and put it in the trunk in easy reach.

Jim

I think if you are going to get to the gas station, you will have to accelerate. And probably go uphill too. Unless you can coast all the way, in which case, who needs gas?

So yeah, the stock pickup might be a problem for putting a hole right in that spot. But, you could go 1-1/2" forward of it and run the arms diagonally. I expect that could even work better.

Jim

Yeah, I like that idea!

The only problem with it is that then you don't have anything down in the little channel which runs from the front to the center of the tank where the stock pickup is attached. But if you are essentially covering the rest of the tank with the arms that only amounts to a couple of ounces of fuel.

This is not a cheap fix. The mat itself, in 15 x 15" costs $300. Plus another $20 for each banjo fitting if you go that way, $10-20 each for any hydraulic fittings, $60 for an assembled fuel rated hose with JIC ends, and so on. Counting the pump, tubing and check valve plus the special fitting for the pump inlet you could easily be approaching $500 before you are finished with it, plus the cost of a quality regulator. (but again, good clones are available at greatly reduced cost)

I still think it's an elegant solution, and with time hopefully the cost will come down a bit. But it is almost certain to be patented (has anybody checked?) so maybe not all that much or that fast.

Jim

I think it's great. I am more interested in a decently baffled tank, for now.

Did anyone have a picture of the stock tank with the round baffle taken from the top?

I'd like to know where the round baffle is in relation to the center rib in the bottom of the tank. I now have all the fittings to do the Roadmaster.

Incidentally, for anyone using a Bosch44 pump and keeping the check valve that comes with it, to do that you need a banjo fitting (12mm to 6an for a 3/8" fuel line, I think you can get that from Techna-fit.com) plus you need an acorn nut to seal off the top of the banjo. It's 12mm x 1.5 and oddly enough lug nuts are available in that size and will work.

Jim

I think Keith Tanner's HIWD includes that photo...

Good catch Curtis. That helps some, but he's done some modifications and I think he's moved things around a bit. Anyone else?

Jim

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