Packard Forum Index » Post-War (1946-54)

I am replacing fuel lines front to back, re:2106..

Currently car is plumbed with parallel lines for the mechanical and electrical pump. Has a one way valve as shown in picture one. The top line is coming from the e pump.

The e pump is mounted on frame just in front of rear wheel at pic 2. The rear most line is going to the mechanical pump.

Someone added a vent line at the carb and ran it all the way back to the fuel tank and welded it to the filler neck.

Why would someone do this - what were they trying to accomplish? Can I get rid of the extra vent line or what do I need to change to get rid of it.

Thanks,
Mark

Attach file:

---

  (88.13 KB)


  (89.92 KB)


  (97.68 KB)


  (89.33 KB)

Look like that line is actually set up as a constant circulation line as was put on some cars in the 70's
and early 80's, it might allow for cooler fuel temps
in the feed line, but I think you would be better off
removing it and shielding the line from excess heat as much as you can, especially near the exhaust manifold.

That looks like a rotary pump and if I had to take a guess, the return line would be there for one of two reasons. One would be the pump has too much flow or pressure for a regular carb and the return line is there to let the excess flow somewhere without stressing the pump or flooding the carb.. Two would be the return line might have been a way to reduce vapor lock. Modern cars use a similar setup only the pump is in the tank. With the return line and fuel continually flowing, there would always be cool fuel available -- at least at the tie point near the pump.

Without knowing the specs of the pump, I would be hesitant to just say get rid of the return. Quite honestly, if it were my car I would get rid of the entire setup and just get a small pulse type pump. Do as most do and go in series with the mechanical and let the mechanical pull thru the electric pump. Equip it with an on/off switch under the dash and single fuel line. Run the pump only for priming or emergency.

If you do want to keep parallel lines so the electric doesn't push thru the mechanical then you would need to keep the tee at the fuel pump outlet, get rid of the return at both ends but add a similar tee arrangement at the tank outlet for the second feed and then run the parallel line back to the engine fuel pump outlet tee. There should be no need for a check valve with the pulse pump but you could keep it if you wanted to.

Here is what I did with mine. Not finished yet because the area is still under construction but pump is in the final location on the frame cross piece just behind the spare tire well. You can get an idea of the mounting position from the photo. When tank is in, short line from the tank outlet will go up and to the left to enter the pump filter. Did similar with my 56. Seems to work well and being high pump is somewhat protected.

Attach file:

---

  (99.13 KB)


  (94.50 KB)

The mechanical is completely disconnected. The outlet hose is shown open. You only need one or the other. But get the right size for the carb, if electric, otherwise you need a return line.
Best to install all new fuel lines, because sometimes they put an electric on back because the line is in bad shape and doesn't flow enough with the mechanical. Steel tubing is cheap. A good mechanical pump with a good line should work just fine.
Regular rubber fuel hose is only good for about 5 years, unless it's the modern lined silicone rubber type which this is not. There's lots of hose on this setup. Only need a short section for flex/vibration of the motor compared to the frame where the line runs.

Thanks guys,
Howard, is that an Airtex pump? Lucky for me the local Autozone has an E-8902 in stock, which I believe is in common use.

It is the E-8011 which is 5-8 psi. Debated on the 8902 but at 2.5-4psi thought it might be just a bit low trying to push that distance and then thru a pump and filtr. I may be wrong and the 8902 is the better way to go. Mine may be too strong but figured I could figure a way to add a regulator or just replace it if necessary. If I had the parallel lines don't think there would have been a question that the smaller would be the better option.

I bought mine from Amazon along with another item to get the free shipping. At around $34 their prices were lower than most places. There were also a couple of good reviews from guys who had the 8011 on a thirties and on a later Packard so we shall see if my install makes a third.

Wow, that all seems incredibly complex for something that doesn't have to be. Why had you rejected the simple and common way of using the mechanical pump with al electric "pusher" back by the tank for priming and in the event you get vapor lock?

Thanks Owen, but I am trying to fix someone else's past mess. I am sure my mess would have been even more elaborate!

Howard, picked up a 8902, installed last night. Will go with a single cupro line - so much simpler and neater looking and far less invasive.

Thanks guys
Mark