I've put electric fuel pumps in quite a few older cars and trucks, over the years, with generally quite good results.

They are meant to be 'pusher' type pumps, rather than 'suction', so, at least per the old mfgrs' instruction sheets, they must be mounted on the chassis frame, as near to the fuel tank as is practicable.

In my opinion, an electric pump is to be preferred with the older Chrysler products sixes, if the car/truck is to be run in hot weather, as in California, as the under-bonnet temperature on a long climb can get pretty warm, and vapour-lock is a real possibility.

What I have done is to make up a 'blank-plate' to cover the original fuel pump mounting on the engine, and route the fuel line as far from the exhaust manifold as was feasible. Wrapping the fuel line in some heat-insulating material is a good idea, as well.

In practice, the original fuel pumps will generally work adequately, if the diaphragm and check-valves are good, the little sheet-metal heat deflector part is properly secured to the exhaust manifold (that heat-shield part originally had a strip of sheet asbestos rivetted to it), and......most importantly....there are no vacuum leaks in the line back to the fuel tank.

On the older cars/trucks, the steel fuel line was secured to the chassis frame by a series of little clips, and held in such a way that dirt and mud could accumulate between the frame and the fuel line, which would hold moisture and lead to tiny rust-through pits in the line. These tiny pits could leak just enough vacuum to degrade the suction of the mechanical pump, causing inadequate fuel delivery to the carbie when under load.

One way to diagnose pitted fuel lines is to disconnect the line from the tank, put a vacuum gage on the line with a suitable fitting, and crank the engine until the gage showed the max vacuum the pump would pull. If the vacuum gage reading dropped off quickly when the engine rotation was stopped, that would indicate either a pin-holed fuel line, or a leaky check-valve in the fuel pump.

Another, and better, test is to disconnect the fuel line at the tank, and plug it. Then, using a regulator on an air line, apply 25-30-ish psi of air to the line. Keep the pressure on the line, and feel along the length of the line......or brush a soap/water mix on the line....to find any pin-holes.

A fuel line which looks sound to a good visual inspection may have a few very small rust spots, some of which can be pin-hoies in the tubing.

The correct repair is a new line, of course, but a 'quick fix' which will work for quite a while is to sand the line clean with 400 emery, paint it with glyp or even hard-setting Permatex, and wrap it tightly with cotton strips, secured with an over-wrap of net-cord or similar, small, strong cordage, knotting the ends. Paint over the wrapping with Glyp or Permatex, and the repair will harden into a certain stop for any vacuum leak.

Its perfectly feasible to put an electric fuel pump back by the tank, and leave the original mechanical pump in line, if the mechanical pump is good. The pressure of the fuel from the electric pump merely runs the fuel through the check-valves of the mechanical pump, and the diaphragm 'idles', so to speak.

Routing the fuel line as far away from the exhaust manifold as is conveniently possible, and wrapping the line with any good thermal insulating material, is still one of the most important aspects of the job, tho.......

cheers

Carla

I use an electrical gas pump in  shunt  setup. 

It is only used for the starting procedure, as the mechanical pump is in good working condition. As I have a 12 V pump in my 6 V system, I didn?t put a pressure regulator.

Works perfectly, but never had to use it as emergency feeding with failing nechanical pump while driving.
I just wanted to avoid to have the starter move the whole engine just to get some gas to the carb.  Above all, I use it since ~10 years to balance out vapor lock plus long parking periods.

Gas line shunt is fuel hoses just clamped together.
Will not be electible when judged. unless You unclamp all back to the original setup.
Greetings! Go

I've heard that if you have a bellows type pump you can route the fuel through the old pump as it can suck the gas through. But if you have the rotary type, you need to bypass the old mechanical pump.

I don't have either, so this is second hand information and you should disregard it if you find a more authoritative answer.

52plym-

My 18th edition MOTOR's manual (1955) lists the fuel pump pressure of the original (mechanical) Plymouth fuel pump, 1947-52, as 3 1/2 to 5 psi. So, if you want to duplicate the setup in my previous post, you would want a Carter P4259 electric pump, a Fram G12 fuel filter, and I can't find the part number for the fuel pressure regulator (it is adjustable), but Summit carries them. You would probably need the regulator to prevent flooding your carburetor. This happened to me before I installed the regulator, and I mistakenly thought it was vapor lock.
I will leave it to others to advise if you should route through your original pump, or bypass it; in my case, I bypassed it.

Pat O'Connor

'52plym-

Not a dumb question at all. I have a 6 volt Carter rotary vane electric fuel pump on my '36. It was around 100 bucks at Summit Racing (they have a website). It will work for positive or negative ground. It puts out about 6 1/2 psi (I'll check for sure in a few minutes, my manuals are out in the detached garage), so you may need a fuel pressure regulator (about 20 bucks at Summit). The advantage of a rotary vane pump over a cheaper bellows pump is that gasahol won't attack the bellows, because there is none.

The manner of installation, proceeding from the gas tank to the carburetor, is: fuel filter (I use an inline clear plastic Fram), fuel pump, and pressure regulator (if necessary).

I'll continue this in a few minutes, I'm going to the garage to check the psi of a '52 engine, etc.

Pat O'Connor

I want to install an electric fuel pump on my '52 Belvedere...everything is standard.   What fuel pressure would be correct ?  Also, any pitfalls that anyone knows of would be appreciated.  Has anyone done this, and if so, what kind of pump did you use and where did you buy it ?  Also, do you just leave the old pump in place ?

Lot's of dumb questions, I know.