BritishV8 Forum

Same place I got the sender...Here it is, EnglishParts.com, Kalamazoo, MI.

1   FLOAT, Fuel Tank Sending Unit, Brass.    JLM772B   $11.69
1   SENDING UNIT, FUEL TANK WITH FUEL PICKUP, 1977-1980    ADU3218   $22.31

Jim

Jim,

Have you thought of getting a newer style Charcoal canister. Ones off the late 90's LR are sealed with three fittings, Tank, Air in and Purge line. Gets rid of any fumes coming out of the MG 5/8 line.

Ever considered the new Nylon fuel lines? Easy to run and every car today runs them as they don't deteriorate from modern fuels. No tools needed if you use the connectors made by S.U.R & R. available at:

https://www.jbtoolsales.com/fuel-system/#/?_=1&filter.categories_hierarchy=Shop%20Supplies%20%26%20Consumables%2FFuel%20System%2FFuel%20Line%20Tools&page=1

Just redid all my lines and it is so nice not having to worry about kinking a line etc when fitting them.

Mike, when it comes to tubing lines of any sort I feel a lot more comfortable with metal. I have found JIC fittings to be a very good balance between cost, complexity, and most importantly, reliability. I tried plastic lines for awhile, for air lines. And while the trucking industry relies heavily on them, I never achieved complete freedom from leaks until I went to metal. Lines suitable for hydraulic service are overkill for low pressure systems, sure, but for reliable plumbing it's hard to beat. Nicopp tubing makes running lines easy enough to make it worthwhile. Good luck finding 1/2" of course, and though aluminum is easy to run it also kinks very easily. So that's a limitation. But still, I feel much more comfortable than with plastic. Just me I guess.

I had the charcoal canister at hand and it is a small part, easy to find room in the trunk for it. A sealed unit probably has merit, but if the charcoal is still good and the car doesn't sit for long periods I suppose it'll work. If not, it shouldn't be hard to change to a different canister. There is a question about theory of operation of course. Does it pressurize the tank? Apply a vacuum to it? Without a vent both of those are possibilities.

Jim

I ran aluminum fuel line in my Camaro & the Roadmaster.

Sender came in, that will be interesting.
Purchased this inline check valve, for $22.50:
http://www.ebay.com/itm/131493328130?ul_noapp=true
Seems high but I saw the assembly photo and it is a high flow piece and should offer little restriction. Best price I could get. Not needed for a carb btw, and I will have a spare if someone wants one.

Getting the fuel out of the tank is the challenge. More on that as I get this sorted out.

I will also be fitting a Bosch 44 clone pump to the Roadmaster, and I think the Holley FPR can be converted to a return regulator just by adding a fitting for the return line (yes, no?) If yes, then I will just have to add the return line to make that work. (No Holley pickup mat in that one, it has a carb. Also doesn't need the check valve.)

Question: Will the late sender assembly physically fit in the early style tank with the baffles? It looks pretty long.

Jim

QuoteQuestion: Will the late sender assembly physically fit in the early style tank with the baffles? It looks pretty long.

No, it won't fit without cutting it down quite a bit  That was the first thing I tried back in 03 when I went to FI.

Thanks, I suspected as much. So that method will not get a return for the Roadmaster as it has the baffled tank, and no other fittings. But maybe I could install a fitting on the old style sender.

Jim

Speaking of tank baffles...

http://www.streetmusclemag.com/tech-stories/fuel-cooling-ignition-tech/ricks-hot-rod-shop-explains-important-baffled/

http://documents.holley.com/how_to_choose_a_hydramat.pdf

The mat you selected calls for a 3.15" tank opening and the mgb tank is only 1.8"

Have you tried fitting it in the tank yet?

Yeah, it'll go in. Now if the fitting was in the center it might be a problem but out towards the end it won't be. I don't think fitting the arms will be a problem either, though the mat is kinda stiff and bulky.

Right now I'm waiting on an internal hose, the check valves and some fittings. I'm prepping the stuff for the RM at the same time but no tank mat for that.

The Bosch 44 pump has an 18 x 1.5 mm inlet. I decided to go with 1/2" line and JIC fittings on the suction side. This means a #8 bulkhead fitting in the tank side wall, I've decided on the lower front corner soon as it gets flat, then a 90 and aluminum line from there to the pump. The check valve has a #6 JIC outlet which matches the 3/8" supply line. Return is 5/16" and will use the old tank suction fitting which is the same size. It uses an oddball nut and flare and I haven't sorted that part out yet. Worst case I'll use a #5 JIC union to mate the lines but a tubing sleeve and bubble flare might work. I will retain the existing sender but substitute a brass float.

On the RM I added a common parts store high flow filter with 16 x 1.5 mm fittings. On the outlet side it matches the 1/2" line into the pump but on the inlet side it will mate to the 5/16" suction line from the tank using several fittings to match it all up. The return will be 5/16" line and will mate to the tube in the new late model sender I just bought, using a compression union. (Well that was a pretty fair plan until I just remembered it's a baffled tank. Back to the drawing board. May have to install a #5 bulkhead connector in the sender plate for the short sender instead.)

Now that bulkhead deserves more description. It is a #8 which means a 3/4" hole in the tank. The bulkhead fitting itself has an integral hex flange with a slight shoulder on the long side and an o-ring groove, so the idea is to attach the internal hose (This is presumably before the mat is in. The hose is Parker 1/2" marine grade fuel hose with female JIC-8 ends, costs about $40.) by first fishing a wire in the bulkhead and out the sender hole, then use that to pull the bulkhead through from the inside with the hose attached. Then center it in the hole, install the o-ring, and cinch down the locking nut, sealing the joint. Since it is kinda important both to tighten the nut adequately and to be able to tighten the connecting 90 without turning the bulkhead fitting, I expect to cut a pair of flats in the shank of the bulkhead fitting in between the lock nut and the 90 nut. Then it is a matter of inserting the mat and getting it into position where it will not interfere with the sender float. The short sender helps. I'll probably use a holesaw to cut the hole. Since they always cut oversize I will have to see if I can get an 11/16" and test it on some scrap. Might end up having to finish it with the die grinder, I have a carbide burr that ejects the shavings back towards the grinder and can use the shop vac to add some suction. Anything that gets past that won't get past the mat.

So. The late model sender was a miscue in either case, but would work with a stock size suction line and an unbaffled tank. I never cared for the lack of a grounding lug anyway, and it's nice to keep the sender purely OEM. Except for the float on mine and the #5 fitting on the RM that is.

I had some tubing come in yesterday so I'll be doing tubing runs while I wait, got all the fittings sorted out today finally (which tends towards confusion and the purchase of unnecessary and expensive hydraulic bits) so from here on it should be pretty straightforward.

If we have any more starvation issues with the RM after this it would not be too difficult to duplicate the pickup in my car in order to go to a 1/2" suction line, at a cost of around $275. With that, the 3/8" supply line and the FPR directly behind the carb, that only leaves a short piece of 5/16" line between the carb and FPR and that could be enlarged if needed. But really, I think this ought to do it.

Jim

One way to add a return:





A #5 bulkhead fitting was cut down, and a nut made out of a lug nut by turning off the flats to reduce the diameter, cutting down the length, drilling the end, and then pressing a T-50 Torque bit through the hole so it could be used as a driver to tighten the nut. The sender flange was drilled with a 1/2" hole, one flat of the hex on the bulkhead was ground down to clear the insulator and then the works assembled with an o-ring and tightened.

Jim

Nearing completion of the fuel system on my car, waiting on a hose and check valve to finish up. Here are a couple of shots, one of the charcoal canister and one of the fuel, vent, and hydraulic lines going over the rear axle, still have to add the 1/2" suction line. I decided to tuck the canister up behind the rear wheelwell. The tank vent is taken off the filler neck and goes through the stock vapor separator before going through the bulkhead fitting in the floor of the trunk and to the canister. That only left the suction line to the engine. Because of the blower I will have to either include a check valve or some other means of keeping boost out of the vent line.

Jim

Jim

Did the HydraMat fit easily through the available hole in the fuel tank?

Haven't done that part yet, still waiting for the hose. Don't see it being a problem though.

Jim

Jim,

Are you adding a tube to your return fitting and aiming it at the supply line fitting on the mat or are you thinking that isn't necessary?

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.