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I start out by defining the issues with my 1950 Packard Series 23 Deluxe 8 Touring Sedan:

1. The starter has to crank a long time to get started if the car was driven and sat for 2 or more weeks. It starts easily once I get it going or if it only sat for a day or 2.
2. The car will vapor lock on a hill on the freeway on a hot day.
3. The original heat shield over the fuel pump is missing. I want to car to look original.
4. The insulating sleeves and washers on the fuel pump bolts are mssing. This may be related to a clacking sound I get from the area of the fuel pump.

My first job is to plan the job:

1. Install an electric fuel pump near the tank to prime the carburetor for starting and perhaps to fight vapor lock while driving. The pump should be for occasional use so it needs a switch on the dash.
2. Install the original heat shield and insulating parts on the fuel pump.
3. Because of difficult access to the bottom of the engine I will remove the side plate on the engine compartment and work through the wheel well.
4. Since I have access I will check the valve adjustment and clean up that side of the engine.


Here is a more detailed list of steps:

1. Research the Packard Information threads to get comments on where and how to mount the fuel pump.
2. Collect all the parts needed for the job.
3. Mount the electric fuel pump on the car.
4. Find a location and mount a toggle switch under the dash.
5. Wire the switch to the pump and test it.
6. Clean and wash off the side of the engine compartment where work will be done.
7. Pull the wheel and side plate from the engine compartment. Paint the side plate and body panels where access permits.
8. Disconnect the fuel line from the pump, drain it, and cut the line near the tank.
9. Install filter and hoses to the fuel line.
10. Remove the fuel pump. Clean and paint the engine where access permits.
11. Fit check the heat shield. If necessary install a stud in the block to replace the rear mounting bolt on the pump. With the heat shield bracket in place this bolt is nearly inaccessable.
12. Install the fuel pump, insulating tubes and washers, and heat shield. Lock the fasteners with wire or use self locking nuts on studs.
13. Remove valve cover plate. Clean and paint it.
14. Check the valve adjustment cold. Adjust if necessary.
15. Install the valve cover plate.
16. Prime the fuel system with electric pump, start engine, and check for fuel leaks.
17. Test drive the car and check for fuel leaks.

Step 1 reveals that there may be a better way of putting the electric pump in the system. I originally planned putting the electric pump in line before the mechanical pump. However if you run both pumps at once you get more fuel pressure than the carburetor wants and you may need a fuel pressure regulator. I have had the cheap regulators fail on several cars, and they do not look original. All bad.

After reasearch on the various PI posts I find a strong reccomedation to put the electric pump in parallel with the mechanical pump. That has several advantanges:
1. No chance of pumping the gasoline into the engine through a failed mechanical pump diaphragm.
2. No rubber hoses under the car where they could be damaged.
3. Fuel pressure at the carburator may be low enough to eliminate the fuel pressure regulator (this depends on the electric pump pressure).
4. Electric pump can be mounted in a cool spot near the front of the car where mounting might be easier.
5. It is easy to test the electric pump versus the mechanical pump if a switch is used.

I plan to investigate this in more detail before I cut metal.

Also I need the mnechanical fuel pump gaskets and the insulating plate between the pump and the block.

Only thing I would add is several have mentioned vapor lock is less likely to form in lines with pressure. Not knowing how or where you plan on joining the two systems, that might be something to consider in a front position. I would think the more of the line you would have under a small pressure, the better the chances for contingency use of the electric pump in case of vapor lock.

I considered this, but the line ahead of the fuel pump is under the car and runs at about ambient air temperature. I measured temperature of the fuel line under the hood after a hot drive and the steel line above the exhaust manifold was about 160F. The fuel pump was pretty hot too because it sits in the hot air coming out of the radiator.

There is a reason every modern manufacturer puts the electric back either in, or near the tank. It keeps the fuel line pressurised so it's less likely to vapor lock. Remember fluid boils easier at lower pressures. Also the electric in the engine bay is going to be subject to a lot more heat than being back at the tank.

Just mount the electric pump up in the frame rail near the tank. If you are using an impulse type pump, the mechanical can draw through it. Typically you should only need the electric when the to prime and as a booster under vapor lock situations. Get a low PSI pump for a standard carb application, and you wont need a regulator.

You can just reuse the factory steel fuel line, reroute and reflare it to fit the output port on the electric up in the frame rail as needed. Then add a small piece of steel line between the tank and the input on the electric. No rubber hoses under the car. Also you should have a fuel filter before the electric one. This will be far superior to the simple metal mesh filter in the inlet side of the mechanical fuel pump.

I'm didnt go that far as using all steel line, as I wanted to be able to service the filter easily and the flare fitting on my tank was compromised already and wouldn't seal. So I used thick fuel injection hose to bridge the tank to the fuel filter, and filter to the pump inlet. Both of which are tucked up in the frame rail. If you are really concerned about the pump being back there, you can build a simple shield metal shield for it to box it easily in the frame rail.

As far as electrical hook up is concerned, I have it attached to a toggle switch under the dash the is powered from a ACC On ignition circuit. So it can only be turned on when the Ignition is also on, and I only use it for priming at this point as I haven't had a vapor lock issue arise.

Being up in the Riverside, CA, I was driving my car around this weekend in 90+ degree heat with no issues running off the mechanical pump only in that configuration.

I just believe that simple is always better. The more complicated something else, the more points of failure. Also unless you got up under the car in the back, you would never see it as everything is still bone stock under the hood.

After some delay I finally got the Packard running well enough for a temperature test. I drove it for over 30 minutes at freeway speed (65 mph) around San Diego bay. The ambient air temperature was about 68 degrees. I stopped and immediately took the temperatures using a laser remote temperature sensor. Here are the locations and the temperatures recorded:

Radiator top tank 180
Core support rear surface on right side of radiator 130
Sheet metal cover in front of radiator top tank 92
Mechanical fuel pump 160
Cylinder block right hand side near front 180
Sheet metal on right side of engine compartment 108
Front of body 78
Exhaust manifold 240
Fuel line on side of frame on left side of car 70
Carburetor float bowl 140
Carburetor mounting flange above insulator 150
Manifold below carburetor flange insulator 210
Water pump near exit 150

This test confirms my intuition. If I mount an electric fuel pump on the fuel line under the car it will be at ambient air temperature. If I mount it on the radiator core support in front of the engine compartment it will be warmer but way cooler than the engine compartment. The vapor locking would happen somewhere between the mechanical fuel pump and the carburetor.

My next task will be to fix the charging system so it will handle additional electric load if I run the electric fuel pump at low speed.

My next task will be to fix the charging system so it will handle additional electric load if I run the electric fuel pump at low speed.

No real need for that, the electric pump electrical draw is trivial and it could run for hours and hours without significantly drawing the battery down. Electric pumps are better at pushing than pulling so mounting it as near to the tank as possible is the preferred location.

Vapor lock should happen first at a line under negative or static pressure; the line to carburetor from the pump will be under positive pressure when the pump is in action so it is the least prone to vapor locking unless it happens to be very close to some very hot, like very close proximity to the exhaust manifold.

PS - the reserve capacity of a 6-volt battery is really quite amazing. With a non-functioning generator and the battery just suppling ignition (i.e., no headlights, heater, radio, etc.) driving 200-300 miles is very doable. JHH (John Harley) who occasionally appears on this forum did it with his 23rd series Packard enroute from NJ to Warren OH a few years ago. As have others in an emergency,

For some reason my Packard does not charge the battery enough for slow driving. At night with the lights on the ammeter shows a discharge. It only charges during the day at speed with the lights off.

Now I have that problem fixed. My Genernator and associated regulator has now been installed. I cranked her up today and the battery was near dead as usual. After charging for an hour with a 6-volt charger the car started right away. The new Genernator shows a good charge at idle! The supplier says it will charge 20 amps at idle and 40 amps as speed. No matter what speed the engine runs there is a good charge on the ammeter.

The genernator is a proper genterator case, fully restored, with a modern alternator hidden inside. The regulator is restored too and wired to run the genernator. The charging control is part of the alternator so there is only one hot wire to supply power and accept charge. The regulator wiring is just for looks. The car looks new and original under the hood.

I will drive the car again after letting it sit for a week and see what happens. Mounting the electric fuel pump is the next task assuming the charging system works well.