1956 Adding a new electric fuel pump

[widgits]

Hello to all
I have been doing some homework on adding a backup electric fuel pump and thought I'd share.
This forum has a wonderful database to search and read through when we need help. So, kudos to all
After reading about the problems of replacement mechanical fuel pumps coming from China plus having to crank the starter too much
when firing up the car after sitting for awhile to fill the carb fuel bowls my obsession has returned.

This was quite interesting just starting with what type of pump to purchase. Many of the Thunderbird parts suppliers have auxiliary electric fuel pumps available
But I wondered again where these were made and how these are installed. Personally, I don't like the idea of plumbing this inline series for a couple of reasons.
Most manufacturers of these pumps recommend installing close to the fuel tank and not under the hood away from engine heat.
And most of these pumps don't create a lot of suction but push fuel much better than pulling, so a short column fuel lift height below 24".
There is NO WAY I would ever suggest mounting this in the trunk!! Bolted at tank height or slightly lower inside the frame on rubber mounts to reduce noise sounds much better.
With nothing sticking below the lowest flat horizontal frame height hanging down

Now back to that inline series plumbing. So the mechanical pump would have to suck fuel through the electric pump and the electric pump would have to push
fuel through the mechanical pump. Thinking I don't like this idea and planning on adding a second fuel line and tee fittings after the mechanical pump.
One way check valves would probably be wise to not back feed fuel. I would worry about a bad mechanical pump diaphragm leaking and fuel going into
my engine block and oil pan. Maybe a small fuel shutoff valve before the mechanical pump should it crap out?

Some safety concerns I have would be to install an oil pressure switch should the engine shut down for reasons other than fuel.
This 12 VDC input should be fused on the control side of a relay.
Inertia switch mounted vertical to rigid sheet metal in case of accident. Somewhere easily reached from inside the car to reset if needed.
This could be wired on the control ground side of the relay. Maybe fab up a bracket fastened inside the glovebox left side?
Maybe prevent getting out on the side of the highway to lift the hood and reset a switch tripped by a big thumping pothole?

A couple of toggle switches wired in could bypass the oil pressure switch should it give up. And the inertia switch if it won't reset.
At the flip of a switch the carb bowls could be filled without cranking the starter. A 2 pole oil pressure switch from the solenoid can turn on the fuel pump but the starter
would need to be running, then automatically switch on from the ignition switch power source.
Planning on tapping into the main oil galley plugs down the Y block drivers side for the extra switches and pressure gauge sensor as needed

I haven't heard or read any good things about cheap $60 plastic housing fuel pumps. And the ones listed from the thunderbird houses don't interest me either for the price.
Instead I spent about $160 on a Facet gold flo pump with fittings, rubber mounts and extra fuel filters. Facet and Purolator are the companies that bought out
the old Bendix fuel pump company and still USA made. But we shall see how much noise this thing makes.
Some of the more expensive Carter pumps seem to get pretty good reviews.

BTW the old teapot carb is outta here and a Holly 465 CFM square bore with vacuum 2nds and electric choke took its place and never a problem since.
This car was purchased for road trips in retirement, last thing I need is failure 1000+ miles from home. Trying to not give it a choice.

Please share with any comments and other ideas!!
Will post more near future
All be well
Bobby

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[Tom Alpers]

I see nothing wrong with your plan. I understand your concerns over the two pumps in series. It would be interesting to see pressure and flow readings at the carb with and without the use of the parallel fuel lines. There were some of the short flexible connecting lines that feed the input port to the mechanical pump which were improperly made with internal fitting holes that were two small that were causing people delivery problems. I run my electric off a relay which itself powered thru a toggle switch and also have an inertia switch in case of accident. Most of the time I don't even turn it on. It would be possible to use the existing oil pressure light switch for the control of the electric pump by using the NC (normally closed) set of contacts.

 

[59tbirddavid]

I wouldn’t use an impulse pump. Diaphragm pumps weak point is the diaphragm. Eliminate the problems using a a brand name rotary pump. Use your safety devices. Block off OEM fuel pump mount port.

 

[Critterpainer]

WOW so much over thinking. Get an original mechanical fuel pump rebuilt and install it. If the car sits for long periods of time without starting (months) then you may want to add an electric fuel pump near the tank and a push button under the dash to activate it long enough to prime the carb. No check valve is needed as the original factory fuel pump has not 1 but 2 check valves in it. Also using the starter to crank the engine for 30 seconds to prime the carburetor also helps the oil pump to pre-lube the engine before starting

 

[widgits]

AGREED !!
I most certainly over think my way through a project. But safety is a #1 priority with anything I do.
This car has a perfectly good working mechanical pump, but should it give out in Burnt Scrotum Utah on a 1000+ mile road trip
far from home where am I going to get it fixed? Done my way I flip a switch and it's safe all the way home !!!
I could just cut the fuel line, tap it in, string some wire from a toggle switch off the battery
Jump in, drive around the block right into a bad accident and BBQ myself in 5 minutes.
Not on my agenda!! This would definitely piss my wife off something fierce !!
New 3 point seat belts are next!!
Some interesting write ups in this forum on that subject
The older I get the more reality kicks in and understanding of how little I actually know!!

Now then, isn't knowledge a wonderful thing to share amongst friends?

 

[vernz]

I've always felt the same way about long cranking after the car sits for a while. Oil has been draining while it sits and I like the idea of building oil pressure before it fires up. Vern

 

[Bruce Hardy]

Hello to all
I have been doing some homework on adding a backup electric fuel pump and thought I'd share.
This forum has a wonderful database to search and read through when we need help. So, kudos to all
After reading about the problems of replacement mechanical fuel pumps coming from China plus having to crank the starter too much
when firing up the car after sitting for awhile to fill the carb fuel bowls my obsession has returned.

This was quite interesting just starting with what type of pump to purchase. Many of the Thunderbird parts suppliers have auxiliary electric fuel pumps available
But I wondered again where these were made and how these are installed. Personally, I don't like the idea of plumbing this inline series for a couple of reasons.
Most manufacturers of these pumps recommend installing close to the fuel tank and not under the hood away from engine heat.
And most of these pumps don't create a lot of suction but push fuel much better than pulling, so a short column fuel lift height below 24".
There is NO WAY I would ever suggest mounting this in the trunk!! Bolted at tank height or slightly lower inside the frame on rubber mounts to reduce noise sounds much better.
With nothing sticking below the lowest flat horizontal frame height hanging down

Now back to that inline series plumbing. So the mechanical pump would have to suck fuel through the electric pump and the electric pump would have to push
fuel through the mechanical pump. Thinking I don't like this idea and planning on adding a second fuel line and tee fittings after the mechanical pump.
One way check valves would probably be wise to not back feed fuel. I would worry about a bad mechanical pump diaphragm leaking and fuel going into
my engine block and oil pan. Maybe a small fuel shutoff valve before the mechanical pump should it crap out?

Some safety concerns I have would be to install an oil pressure switch should the engine shut down for reasons other than fuel.
This 12 VDC input should be fused on the control side of a relay.
Inertia switch mounted vertical to rigid sheet metal in case of accident. Somewhere easily reached from inside the car to reset if needed.
This could be wired on the control ground side of the relay. Maybe fab up a bracket fastened inside the glovebox left side?
Maybe prevent getting out on the side of the highway to lift the hood and reset a switch tripped by a big thumping pothole?

A couple of toggle switches wired in could bypass the oil pressure switch should it give up. And the inertia switch if it won't reset.
At the flip of a switch the carb bowls could be filled without cranking the starter. A 2 pole oil pressure switch from the solenoid can turn on the fuel pump but the starter
would need to be running, then automatically switch on from the ignition switch power source.
Planning on tapping into the main oil galley plugs down the Y block drivers side for the extra switches and pressure gauge sensor as needed

I haven't heard or read any good things about cheap $60 plastic housing fuel pumps. And the ones listed from the thunderbird houses don't interest me either for the price.
Instead I spent about $160 on a Facet gold flo pump with fittings, rubber mounts and extra fuel filters. Facet and Purolator are the companies that bought out
the old Bendix fuel pump company and still USA made. But we shall see how much noise this thing makes.
Some of the more expensive Carter pumps seem to get pretty good reviews.

BTW the old teapot carb is outta here and a Holly 465 CFM square bore with vacuum 2nds and electric choke took its place and never a problem since.
This car was purchased for road trips in retirement, last thing I need is failure 1000+ miles from home. Trying to not give it a choice.

Please share with any comments and other ideas!!
Will post more near future
All be well
Bobby

I thought this whole thing is way over thought. Here's my idea. Eliminate the mechanical pump.Either get a blockoff plate or just leave it there. disconnect the fuel lines and join them together. Install the electric pump by the fuel tank so thre's minimum distance for the pump to suck and simply connnect the electric pump to the original gas line. wire the pump to your ignition switch with a relay if you want. Just have it work with key on only.It will not come on in the start mode but so what. You'll get use to ,by counting, how long the pump will take to fill the carb and off you go. If the pump won't prime initially, Wrap a rag around your air hose and put some pressure in the tank. With the pump running you'll here the sound from the pump when it goes under load.You should only need to do it once only unless you run it out of gas, then you'll need to repeat. I
know all this because I've done it on two cars. And thanks for listening..

 

[Jim5]

On my 55 (still 6v), I cut an electrical pump inline along frame rail approximately where the driver’s door is. Connected wire to ignition switch. A toggle on/off is a good idea, but I don’t have one. (If there was an accident, yes, the pump would keep running - bad idea, I know). I pump inline through the existing mechanical pump which is a little weak. I have at times completely bypassed the mechanical pump. Definitely the best for starting after sitting for awhile. Pump is made by Fifth Ave Antique Auto Parts. www.fifthaveinternetgarage.com
Very durable, custom designed for ralley drivers. Available in 6v and 12v. I also have a Holley pressure regulator in line before the carburetor and set at 3 lbs.

 

[dadspony]

I added and 12V electric fuel pump last year and back about 4' from mechanical pump. It pumps at a constant 5psi through the mechanical pump and into the carb. Pump activates when ignition switch is turned on. I did paint it black like the frame just so it wouldn't be so obvious. It works great, no leaks but I know it should be closer to fuel tank.

 

[Critterpainer]

Just a warning. If you go to salvage auction websites IAAI or CoPart and do a search for classic or antique vehicles you will find the majority are burned, not collision. If you install an electric pump, wire in a manor that shuts the pump off if the engine stalls or quits running. Many electric pumps can be wired in such a way that the loss of oil pressure shuts off the pump. All modern cars have impact sensors that trip to turn off the pump. In days of old manufacturers used steel lines from the fuel pump to the carb.

 

[Kultulz]

"Also using the starter to crank the engine for 30 seconds to prime the carburetor also helps the oil pump to pre-lube the engine before starting."

That is called 'dry starting' and causes much/most of the engine wear. She needs to fire right off so the oil pump can pressurize the system.

With an electric pump (primer or supply), it (electric primer pump) is run until the fuel bowl(s) are filled hopefully allowing a fast start.

If running an electric primer only pump (w/ a mechanical pump) without a fuel line bypass circuit, it has to have a/the proper flew-thru rating.

​

 

[Tom Alpers]

Yes you do want to crank, without starting, an engine that's been sitting. No different then running the oil pump to prime a just rebuilt engine so you don't wind up loading the rods and mains before there is any pressurized oil there to protect the bearings from the cylinder explosion force.

 

[dadspony]

On my 57 Bird I just in lined the electric pump which then run through the mechanical pump. Holds constant 5 psi and runs and starts way better.

 

[Kultulz]

Yes you do want to crank, without starting, an engine that's been sitting. No different then running the oil pump to prime a just rebuilt engine so you don't wind up loading the rods and mains before there is any pressurized oil there to protect the bearings from the cylinder explosion force.

Of course you have torn down engines, mic'd and had oil analysis done to prove that?

The last thing one wants to do is perform a cold crank on any engine especially one that has been put to sleep over a cold season. Same on an engine that has lost it's fuel prime, the constant cranking will not provide the necessary oil pressure or volume to prevent damage(s) (and also overloads the starter motor). And once she fires it will most likely introduce an overly rich mixture which will blow past the rings and foul/thin the crankcase oil.

A 'fresh' engine will have (hopefully) special lubricants and assembly lubes that will lessen the first fire effects, but still should be primed turning the oil pump (electric drill) and rotating the crank assembly by hand (especially with a flat tappet cam) (turn crank by hand just one revolution with a flat tappet cam so as not wipe the assembly lube off the cam lobes and/or tappets). The fuel and ignition timing must be exact for an immediate first fire. If she doesn't fire first attempt, find the cause, and not continuing cranking and cussing.

An engine having been sitting will have lost most oil films, depending on the quality of the oil, length of sit and clearances.

Cold weather start will just make it worse.

If the engine suffers from carb bowl percolation or improper fuel pressure/carb settings, the carb fuel bowl(s) have to have gas added via the vent(s) or use an electric pump (primer, transfer or supply) to fill the bowls. A mechanical pump may not always have the suction to bring fuel up from the tank/lines and is why you trickle gas into the throttle body while cranking. Once she starts, the mechanical pump will (should) develop enough suction with engine RPM to bring the fuel to the carb (if the pump is good).

Again, cold starts (along with improper servicing) is the leading cause of internal engine wear. Cold cranking does not lubricate the engine properly. That happens when the engine fires and oil pressure/volume is brought up to spec.

How much does an overhaul or HP engine cost theses days?

 

[Tom Alpers]

You believe what you want.

 

[SHA BOP]

My 55 has been with me since 1987, I'm second owner and I feel responsible for maintaining it as close to original as possible. My OEM fuel pump must be 20 years old and the Tea Pot carb was overhauled about 20 years ago. Still runs great. I added an inline electric pump to prime the carb or to use in case the mechanical pump fails. I added a filter into and out of the electric pump. The OEM glass bowl filter is still in place. The electric pump has no restriction for the mechanical pump to draw fuel from the tank through the inline elec pump. I have a hidden switch under the dash for the elec pump. I tend to keep it simple. I have made many upgrades but nothing is visible to change the appearance from the original appearance.

 

[SHA BOP]

The simple solution to priming the engine with an electric pump is to prime "after" you have run the starter for 30 seconds. My electric pump has a separate switch and does not run unless selected.

 

[Kultulz]

The simple solution to priming the engine with an electric pump is to prime "after" you have run the starter for 30 seconds. My electric pump has a separate switch and does not run unless selected.

😵 ... why?

The point is to ensure the carb bowl is full (correct fuel bowl level lost due to heat percolation or from internal leakage into the carb itself) for a no-crank fast start (if state of tune is correct) and resultant (hopefully) proper oil flow. If you dry crank for thirty seconds the mechanical pump should fire it.

Why drag the engine? Why the expense of an electric primer pump?

 

[SHA BOP]

My engine was completely overhauled a few years ago, I added electronic ignition a few years ago, had the carb and mechanical fuel pump overhauled a few years ago but the car is 70 years old and it often will not start (after weeks in the garage) with 30 seconds of grinding the starter to mechanically suck fuel from the tank to a dry carb float bowl. I installed the inline elect pump myself at minor expense and it has made a world of difference for me over the past 10 years.

 

[simonsma]

As a purist I tried to keep my 55 Thunderbird as close to original as I can. Being 6 volts and positive ground looking for an electric fuel pump that would not over pressurize my system and still have the capabilities of drawing fuel through it when not in use and is use the stock fuel pump system was my goal. I did not want to cut the fuel lines or modify them but I did remove the coupling in the frame section and installed an electric fuel pump with the filter that is 6 volt and I used a small push button switch hid underneath the dash to activate the fuel pump when needed. Normally I don't use it but if the car's been sitting for a week or two rather than crank on it and lean on my starter I activate my electric fuel pump for a few seconds filling my carburetors I'm cranking the engine which starts immediately. I have also found that if I have a vapor lock that I can simply reach underneath the dash and engage the electric fuel pump for just a moment which clears up the vapor lock instantly. I run the stock fuel pump 100% of the time and draw through the electric fuel pump and filter all the time and activate the electric fuel pump as needed.