Electric fuel pumps

[Grant L. Meredith]

My inquiry is 6 volt fuel pumps.  Inline pumps seem to short in life span.  Been through 2 for the short miles I put on the car. 
Has anyone ran a 6 volt pump by Carter p/n4259? It’s a larger pump with 6psi pressure. 
Or I thought of taking the car back to vacuum as the car retains all its vacuum components, with an inline as a backup. 
 

Thoughts?

 

Thank you

[Grimy]

I've used that same pump (actually, NAPA P4259 or Airtex # E84259) on my 1930 and 1934 Pierces (both 8-cyl) successfully for more than 15 years.  A few suggestions:

- They are NOISY, so insulate with rubber sheet as well as the supplied grommets.  They have a separate ground wire so don't worry about insulation messing up the ground

- Use a high-quality pressure regulator.  I use Holley #12-804 (1-4 psi) set to 3 psi.

- You will need a bypass so that your mechanical pump can pull fuel up long grades.  Use two tees plus a check valve.  Stay away from the two-piece (diesel) valves, identified by wrench flats at the center) if you might encounter ethanol fuels because their diaphragms will not survive ethanol (ask me how I know).

- I recommend not running the 8-amp draw through your ignition switch.  Use a relay under the dash where the ignition must be on to turn the relay on—draw for the relay thru my OEM ignition switches was measured at 0.07 amps.  A friend found an old Bosch 12V miniature relay with metal case that works well on 6V, and he says other 12V miniaturized relays don’t perform well at 6V.

- Suggest a 3-way toggle switch (ON)-OFF-ON with the parentheses indicating holding against spring, use that for priming.

- Others may suggest using an oil pressure sensor to kill the fuel pump if the engine dies, as in an accident, heaven forfend.

[Grant L. Meredith]

Thank you for the advice.  I appreciate it. 
No mechanical pump on a 1928 so good there.  I have that regulator already on the car.   Great advices  Grimy

Edited May 25, 2023 by Grant L. Meredith (see edit history)

[Mark Shaw]

I too run an Airtex # E84259 in my 31 Model 67 Buick as the primary fuel pump.  The mechanical pump push rod support is missing from the engine, so I cannot run the original mechanical pump.  Cheap solenoid pumps do not last and have sidelined many old cars during car club events.  I also suggest a large capacity fuel filter to protect the pump and carburetor.  Carry a spare filter just in case.

[Grant L. Meredith]

Mark I’ve ordered my last inline.  I’ll go this way with a larger filter and this pump from Carter.  
What I’ve read in the ad for the pump sounds like a quality pump. 
Thank you Mark

[Hubert_25-25]

Grant, 

    Consider installing two electrical pumps in series.  Whatever pump you buy will eventually fail.  I did not install 2 switches, you could, but I am able to reach the pump from under the car and I just swap in the spade terminal on the other pump when I need to use or run on the other pump.  These pumps have no problems connected that way.  I dont mind getting under the car to switch the electrical wire, but its not so much fun dealing with fuel lines.  

 

Also consider the E8902 pump which is the 6 volt lower pressure 2-4 psi alternative and does not require a regulator or a relay.  Note also that these have become very scarse, and you need to read the fine details from all the different sellers as many of them call their pump an E8902 when it is not based on the specs.  Most are out of stock also.  Onix EH902 is another variation, but read all the information closely before ordering as sometimes I see these listed with a higher pressure in the fine print which is another model.

 Hugh

[BuickTom87]

I just ordered the carter pump for my 29 buick. Im hoping for good results

[John Nelson]

I’m new to American antique cars and in the process of restoring a 1924 Buick Standard Six Phaeton that is unfortunately missing the entire Vacuum fuel pump system which so far I have been unable to source. Due to this I have been considering going to an electric pump and was considering using a transistorized SU pump, has anyone had experience using this pump? 

[Hubert_25-25]

John,    

   Using the word "Standard" in the description of your car is misleading.  It is a 1924 model 45 Touring.  You can also call it a 1924 6 cylinder.  Master and Standard were not used as terms until 1925.  If you do want to use a reference, Master is more appropriate as you have the larger engine. 

 

Your car has a metal needle and seat in the carburetor.  These are quickly overrun with fuel pumps that have too high a pressure.  The fuel pressure on these was based on a 2 foot liquid level of fuel coming from the vacuum tank to the carburetor.   1 foot of water is 1/2 PSI so the needle and seat only has to seal against around 1 psi.  Low pressure 6 volt pumps are in the 2-4 psi range.  These are getting harder to find.  Most common are the 6 volt pumps in the 6-8 psi range.  I do not know what pressure an SU pump puts out, but it is looking for a certain amount of back pressure on the needle and seat to prevent the electromagnet from toggling.  Again, I think the pressure is too high. 

 

I do make viton tipped needle and seat kits for Marvel carburetors.  You will need to go thru your carbutetor and replace the venturi as potmetal growth prevents the carburetor from working properly.  Look into replacing the float as well.           

 

If you acquire and put the vacuum tank back in service, they work well, but you do need to watch for vacuum leaks. 

 

Hugh 

 

      

[John Nelson]

Thanks Hugh, you are a wealth of information!!! I’m currently going through the engine and transmission. The engine actually looks to be in very good condition other than a good bit of sludge in the oil, bearings look good  to so my plan is to replace the rings and either lap the valves or have them ground if they need it. Also to clean out the sludge and make certain the oil passages are clear. Then reassemble and repaint to the proper color.

John 

[John Nelson]

Thanks Hugh, I do plan on putting it back to original and you’re very likely right the SU pump would be to high a pressure to use, there was an issue with that on my MGA also. On it I went to “Grose Jets” which used a ball type valve. Right now I’m up to my eyeballs in the transmission and engine but do appreciate the info on the carb issues.

John 

[Hubert_25-25]

John, 

    Why don't you start a new thread with a photo so we can see what you are working on.  Hats off to you for doing the right thing and dropping the pan.  I have a car in my shop where an owner did not do that, and his rebuild would have been less expensive if he had done otherwise.  People don't understand non detergent oils.  Non detergent oils let the sludge settle out.  Pull the dip stick on a car with non detergent oil, and the oil looks really clean.  But the oil pick screen is in the muck.  In later Buicks, the oil filter was eliminated when Buick went to a floating suction.  Not only does the muck settle in the sump, it also settles and clogs the oil passages. 

 

Be sure to closely inspect the screen on the oil pick up, and all the solder joints in the bearing oil feed tubing.  

Hugh   

[Grimy]

2 hours ago, Hubert_25-25 said:

People don't understand non detergent oils.  Non detergent oils let the sludge settle out.  Pull the dip stick on a car with non detergent oil, and the oil looks really clean.  But the oil pick screen is in the muck. 

AND...the sediment also settles out in the oils galleys/galleries and in the crankshaft and other oil passages.  Attached are two photos of a friend removing "crank turds" from a 1919 Pierce-Arrow crankshaft.  How much oil do you think was getting through these occluded "arteries"?

[Hubert_25-25]

This is the oil feed line to the head.  

 

[critterpainter]

Why can't you use the original style vacuum tank?   Most tanks can interchange between makes and when properly restored work quite well.  I enjoyed having a good working vacuum system on my 29 Plymouth as most people had never seen such a thing.   If the engine has a good valve train it should work fine.    As a bonus its easy to prime!

 

[Brian_Heil]

I’ve posted this comment several times before and will do it again here for the newer folks. 

 

In 27 years of nickel era car touring I’ve seen 3 engine fires.  All three were related to an electric fuel pump overcoming the stock carburetor. 
 

A S/W vacuum fuel pump supplies fuel to an updraft carburetor at about 0.3 PSI. I’ve done the head pressure calculation. 

 

If you can get your electric pump regulated down to that you will be fine.  If not, keep your insurance policy premium paid. 
 

Carry a 5 lb extinguisher not the little one. 

Edited June 2, 2023 by Brian_Heil (see edit history)

[Brian_Heil]

2.31 feet of gasoline = 1 psi

 

Measure from the mid height of your S/W tank (all the higher the fuel gets in there) to the height (bottom) inlet of your carb bowl. 
 

Remembering our 5th grade fractions

 

1/2.31 = X psi/your dist in feet

 

solve for X

 

0.433 x your dist in ft = head pressure in psi for gasoline

On my 1923 Buick that distance is 8 inches which is 0.67 feet

 

0.433 x .67 = 0.31 psi

 

Edited June 2, 2023 by Brian_Heil (see edit history)

[Ben Bruce aka First Born]

 I don't have a dog in this fight.  Having said that, I do have a question.    I have never owned a car with a vacuum tank fuel system.   BUT.  Assuming a person can not make the vacuum tank work, for whatever reason.   Cannot get gas to tank. Tank to carburetor is ok.  Why not use the electric pump to keep the tank full?   A robust LEVEL switch could be used.   Not wishing to start a war here.  Just curious.  

 

  Ben

[Brian_Heil]

In principle, yes. 
 

The S/W tank needle sealing valve is non robust like the early carb needle and seat so that could be an issue

 

As Hugh has mentioned, you could update the needle and seat in an early carb to Viton so it could handle higher pressures and people have done this   Same could be done to the S/W tank. 

Edited June 2, 2023 by Brian_Heil (see edit history)

[Hubert_25-25]

There is not a needle and seat in the vacuum tank.  That is why it would be difficult to control the flow of a fuel pump with the vacuum tank still in series to the carburetor.  The vacuum tank is a tank within a tank.  There is a large float inside.  The float operates a break over arm.  The breaker arm directs the valves in the top of the tank lid to be either ONLY in vacuum or venting.  So the vacuum tank is either under vacuum (open to the intake manifold vacuum) or venting (allowing fuel to be drawn out).  There is a flapper valve between the 2 tanks to keep the vacuum from effecting the fuels ability to get to the carburetor.    

 

It's easier to install a viton needle and seat into a carburetor, than it is to retrofit a vacuum tank that never had a needle and seat in the first place.  That said, if you installed a set of electrical contacts for the high level, and contacts for a low level switch, you could shut the pump power on and off to the fuel pump, rather than cycling by level.  Then the switches have to be kept from fuel vapors or be intrinsically safe switches.  Yes the "system" could be reinvented and all the more reason to carry a fire extinguisher.         

 

Hugh

 

[Grant L. Meredith]

My ‘28 still retains its vacuum tank system Hubert.  Thank you for the explanation with diagrams.  I thought of pumping into the tank now I won’t. Mind you I hadn’t taken time to study it. You just saved me that time.  I regulate my electric to 0.5 psi approximately. 

[Grant L. Meredith]

I have the rebuild kit bought from Bob’s.  I guess I know what project I should be doing in the near future

[nat]

2 hours ago, Hubert_25-25 said:

That said, if you installed a set of electrical contacts for the high level, and contacts for a low level switch, you could shut the pump power on and off to the fuel pump, rather than cycling by level. 

          Surely you jest.

     Two strategically positioned explosion proof switches, (only high level would be necessary), inside the vacuum tank?             Wires going in and coming out?  

     At 99 1/2 years old, my vacuum tank works flawlessly.  Sometimes my carb doesn't.  I don't see an electric fuel pump in my future.

     

[Ben Bruce aka First Born]

1 minute ago, nat said:

          Surely you jest.

     Two strategically positioned explosion proof switches, (only high level would be necessary), inside the vacuum tank?             Wires going in and coming out?  

     At 99 1/2 years old, my vacuum tank works flawlessly.  Sometimes my carb doesn't.  I don't see an electric fuel pump in my future.

     

 

 Has anyone heard of an IN TANK pump  causing an explosion in a modern car?

 

  Ben

[nat]

   

 

6 minutes ago, Ben Bruce aka First Born said:

Has anyone heard of an IN TANK pump  causing an explosion in a modern car?

In tank pumps are "explosion proof".  Like explosion proof switches they have seals that isolate the contacts from the hazardous side.

     

[Bloo]

Err... not exactly.

 

Usually the fuel literally runs through the motor, and the commutator, sparks and everything. The fuel is used to cool and lubricate the motor, and keep all the debris washed out of the commutator. Gasoline will only ignite in a specific range of mixtures. Shooting from the hip because I can't remember the exact numbers, that's about 8:1 to 16.5:1 (by weight). The gas tank traps the vapors inside, and the mixture in there is always too rich to ignite, even when you are running out of gas.

 

Don't try to bench test one.

 

Edited June 2, 2023 by Bloo (see edit history)

[edinmass]

1 hour ago, Ben Bruce aka First Born said:

 

 Has anyone heard of an IN TANK pump  causing an explosion in a modern car?

 

  Ben

Duesenberg had in the tank electric pumps in 1931. 

[Brian_Heil]

Hugh’s right, you would have to reconfigure the valving and the whole S/W tank. 
 

My point in all this is don’t be that guy who just hooks up an electric fuel pump to his early car and thinks everything will be fine. 
 

Knocking on wood here as my stock S/W pump has served me well for decades and I’ve had enough mystery headaches this Spring.  They are very reliable and rugged if set up correctly and not allowed to sit with bad gas for years like some cars do. 

[Morgan Wright]

I have two extra SW vacuum tanks. If you need one PM me and make an offer. They are for 1918 but I don't think there's much difference.

[nat]

11 hours ago, Bloo said:

Usually the fuel literally runs through the motor, and the commutator, sparks and everything.

     Most modern cars do have in tank pumps and no, I've never heard of one causing an explosion.  I'm amazed that there aren't circumstances, (like removal and reinstallation of a tank), when the atmosphere would be explosive.

[Morgan Wright]

21 hours ago, Bloo said:

The gas tank traps the vapors inside, and the mixture in there is always too rich to ignite

 

 

I always got a kick out of milk jug bombs. You take a plastic gallon milk jug and fill it with butane gas. All it takes is a good long squirt from a butane cigarette lighter refill thing. 3 or 4 seconds of gas. Now, light it. All you get is a small flame on top, like a candle flame. The butane in the jug won't burn because it's too rich.

 

The following must be done outdoors.....

 

Give the jug a good squeeze. BOOOOOOOOOOOOM!

[Bloo]

[28Buick]

On 6/2/2023 at 6:50 PM, Ben Bruce aka First Born said:

 Has anyone heard of an IN TANK pump  causing an explosion in a modern car?

Apollo 13. Technically not a modern car, but a modern space craft designed with the best technology available at the time. 

 

I'm posting here for the first time as my 1928 Standard runs great on the fuel I pour into the vacuum tank, but is not pulling anything out of the rear gas tank. I can create waves in the gas tank by blowing air into the banjo joint tube at the vacuum tank.  Looks like a vacuum tank rebuild may be next. I just ordered the rebuild kit from Bobs Automobilia. What else do I need for this job? Thanks to all for good advice.

 

[Hubert_25-25]

There is a screen on the fuel line that sticks into the fuel tank.  It is likely perished like the filter screen on the oil suction.   

Edited August 4, 2023 by Hubert_25-25 (see edit history)

[Guest]

An electric pump will have it's life increased 2-5 times if mounted where the discharge is up.

[Larry Schramm]

On 6/2/2023 at 6:50 PM, Ben Bruce aka First Born said:

 

 Has anyone heard of an IN TANK pump  causing an explosion in a modern car?

 

  Ben

There is a narrow range of oxygen to gasoline that an explosion can be created.  Outside of that relatively narrow limit there is either not enough fuel to oxygen, or too much fuel to oxygen concentration.  The range for an explosion to occur is 1.4% to 7.6% fuel to air.  Fuel tanks have too high of a concentration gasoline vapors to explode, unless broken open which is rare. Look here for more information.

 

https://www.google.com/search?client=opera&q=what+is+the+uel+lel+levels+for+gasoline+to+ignite&sourceid=opera&ie=UTF-8&oe=UTF-8

 

 

 

Edited August 4, 2023 by Larry Schramm (see edit history)

[edinmass]

 

Look up the definition of the word stoichiometry.............Duesenbergs used electric pumps in the tank in 1930..........Stewart Warner six volt sealed units. 

[60FlatTop]

On 6/2/2023 at 12:57 PM, Brian_Heil said:

2.31 feet of gasoline = 1 psi

 

Measure from the mid height of your S/W tank (all the higher the fuel gets in there) to the height (bottom) inlet of your carb bowl. 
 

Remembering our 5th grade fractions

 

1/2.31 = X psi/your dist in feet

 

solve for X

 

0.433 x your dist in ft = head pressure in psi for gasoline

On my 1923 Buick that distance is 8 inches which is 0.67 feet

 

0.433 x .67 = 0.31 psi

 

I serviced a 1932 Hudson Greater Eight one time. I gave the owner back the diecast fuel pressure regulator that I removed from the fuel line about 6" below the vacuum tank.

 

And I told him to watch out for these guys. They are still out there "reckoning".

Edited August 4, 2023 by 60FlatTop (see edit history)

[28Buick]

13 hours ago, Hubert_25-25 said:

There is a screen on the fuel line that sticks into the fuel tank.  It is likely perished like the filter screen on the oil suction.   

Screen? What screen? Just pulled the fuel line as shown, it required a 3 foot breaker bar to unscrew. What do you suggest, same screen mesh or different from the oil pickup? 2nd pic shows something that might affect the fuel draw. I have never seen a copper fuel line fracture like this.

[Hubert_25-25]

Same screen as used on the oil suction.  Instructions on how to build the sock are above.  The copper tubing used back in the day is very inferior.   I bought a fuel line from another car and it was rolled into a 2' diameter coil.  After unrolling it, it was full of holes.  The crack in your straight section of tubing is interesting as it is just a straight piece. 

Photo of all the holes in the fuel line, the sock that I made and installed, and the copper that I bought.   I built the mesh sock using a bolt wrapped with aluminum foil.  5/16 copper tubing is getting harder to find.  I can no longer get it at Lowes.    Hugh

 

  

Edited August 4, 2023 by Hubert_25-25 (see edit history)