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I overhauled my mechanical fuel pump. the system is so completely original.
Can I put an electric fuel pump in the line so that I can have it pumped briefly after a long period of standstill?
Did any of you build it like that? Makes sense?

Greetings and thanks
Mike

Might as well just bypass the mechanical one in that case. I wouldn't connect them in series, though it might work.

Some members on here will simply crank in bursts until the fuel gets going. There is also the trick of starting the car on starter fluid or gas from a laboratory bottle.

I don't know if there is any feasible way to manually fill the carb bowl, but that might be another option.

I have an electric pump inline with the mechanical. I only use the electric to prime the when the car has been sitting.

I've had no issues with the mechanically pulling fuel through the electric pump when it is off.

But, you have to get the right style electric pump for that to work. Impulse-style pumps work fine for that. Rotary pumps do not.

I have the pump wired via an under-dash switch and hooked to ON position on the ignition switch. I usually will turn on the electric pump until I can hear it pressurize the line (tone-change in the pump) and then turn it off. The car then starts on the first attempt, even after sitting for a couple of months in the Midwest cold, without any excessive cranking. Usually, in the first 2-3 seconds.

The only electric fuel pump I ever had in a Packard was in my 1953 Clipper Deluxe when I bought the car and if it had a switch, it was never off. It was a diaphragm type pump mounted on the frame in front of the tank that worked only when needed so when the key was turned on, it would go bump, bump, bump to pump the fuel up to the carburetor, then shut off once there was pressure. I doubt it ran much when the car was driving but if it did it was silent over the purr of the engine.

Though I don't think anyone has ever heard of this happening, if the mechanical fuel pump would fail (leak) with the electric one on, it would shoot gas into the oil pan and ruin the oil. Though as long as the electric is only used as needed and is the correct style as Kev mentioned, I think it would be fine.

I also have a stock mechanical fuel pump with a separate electric pump at the gas tank in my '35 Super Eight. It has a toggle switch under the dash that I use only to start the engine

I have a Hardi pump from Germany. I wrote them an email today and they replied immediately. The pumps are suitable for this and the mechanical pump also pulls the petrol through there when the pump is switched off. So I can just put them in between.

I too have the above described setup on my '39 six. It works well and is needed as I usually go weeks in between starts in the summer with my travel schedule. I also worried about the electric pump forcing fuel into the crankcase via a leaking diaphragm but always turn the electric pump off as soon as the engine fires and let the lift pump take over, so I think it is a reasonably safe arrangement. Chris.

You can do this with a solenoid (clicker) type pump as they allow fuel to flow through when the pump is off. It won't work with a rotary or vane type pump as they won't allow fuel to flow through when the pump is off.

I have a 6-volt pump in series and parallel with a normal fuel line.

I installed my pump with a switch used primarily for assisting if the car has sat for a while. After starting, I typically turned the electric pump off. BTW, when the pump has built up pressure, they typically don't make noise. They really only make noise while building pressure.

I also have a direct feed with a check valve mounted parallel to the pump so that the mechanical pump can pull through the check valve and allow the car to run normally. The check valve keeps the electric fuel pump from sending fuel back to the tank in the parallel line.

I did all of this for 2 reasons.
#1 I didn't want to for feed my mechanical pump and possibly cause a seal in the mechanical pump to fail and allow fuel into the engine.
#2 I didn't want to over pressurize, so I would have needed a pressure regulator, but that wouldn't have relived my worries of #1
#3 I like redundancy with a solid backup.

I used to have turned on the pump on long uphill pulls on my tired engine. I hope the rebuilt engine doesn't need the electric pump.