Fuel Pump Pulling Fuel "Uphill"?

[DrDoctor]

QUESTION: Will the mechanical fuel pump on a Plymouth 218 6-cyl flathead pull fuel uphill?

SCENARIO: 1946 Plymouth has: 1) ACDelco glass bowl fuel filter mounted just in front of carburetor; 2) ACDelco (#GF-62) canister-type fuel filter mounted near top edge on right inner fender; and 3) new fuel pump (Airtex #73201). Pump pulls fuel from tank, up approximately 16" to/through canister fuel filter on inner fender, back down into fuel pump, and then pushes the fuel back up approximately 18" to/through the glass-bowl filter, and into the carburetor. So, is this too much for the "pulling" side of the fuel pump to handle long-term/successfully?

 

[desoto1939]

Why not put the fuel filter as an inline prior to the FP and maybe back by the fueltank. This way you catch any thing there first and eliminate the plumbing.

 

I also have the AC glass bowel filter assembly just prior to my carb on a 39 Desoto with the same fp which is an AC588.  Are you getting any problems currently with this setup is the first question that people are going to ask?  I do not think you should have any issues.

 

Rich Hartung

desoto1939@aol.com

Edited November 8, 2016 by desoto1939

[DrDoctor]

Thank You for your response. I've thought about moving it back near the fuel tank. I had a '65 Pontiac Catalina full custom (chopped, sectioned, channeled, lowered, restyled, the "whole nine yards", as they say . . .), which had a supercharger on the engine. I had to run an electric fuel pump (Stewart Warner #210(?)) right by the fuel tank. I put a large Fram fuel filter between the pump, since it was quite expensive, and the tank, and never had a problem. So, that's why I think that's probably the way to go, and your opinion reinforces that decision. Again - many thanks for your input, I really do appreciate. Thx.

[Los_Control]

sounds good to me also, put the filter before the pump and one after the pump is what I will run.

Something I have been told over the years, and car manufacturers confirm.

A electric pump will push a long ways, why it is back in the tank.

A mechanical pump will pull a long ways, why it is up front on the engine..

I doubt the current setup with canister on the fender is a issue, but think it would be better to have it before the fuel pump.

Just working with my pump to clean it up and prepare it for first startup, is a mall screen in the pump that would not want to get clogged.

My pump has a glass bowl, but no filter, so have a filter for between pump and carburetor and will add between tank and pump.

 

[Don Coatney]

7 minutes ago, Los_Control said:

 so have a filter for between pump and carburetor and will add between tank and pump.

 

 

That glass bowl filter between your pump and carburetor line size looks way too small. Doubtful it will supply the demands of your engine. 

[Los_Control]

I have to admit that it is not original to the truck, but if you remove the brass fittings on the pump and the carb, all inlet sizes are the same.

So I thought it should work, dunno. Plan to just install same brass fittings as in the pump to convert to 5/16"

 

Edited November 8, 2016 by Los_Control

[DJ194950]

There can Big differences between a stock type Vacuum pull/pressure output fuel pump ( very good at pulling) and many electric fuel pumps.

Most electrics do Not pull good, built to mostly push ( most not too great a pulling much) and most cannot stand much/very little thrash. That is what creates the the need to mount electric pumps close to the tank and put a filter before the electric pump (on most) . Most electric setups also put a smaller fuel filter just before the carb./injectors. Electrics also are available to stand some thrash depending on make/model- see each ones manf. spec before purchase.

Back to posters Q. I see nothing wrong with current setup with stock type fuel pump.

DJ

[desoto1939]

1 hour ago, Don Coatney said:

That glass bowl filter between your pump and carburetor line size looks way too small. Doubtful it will supply the demands of your engine. 

Don:  I have the stock Ball and Ball carb on my 39 Desoto and the stock fuel pump which is the AC 588 that has the glass bowel and just before the carb I have another fuel bowel which is the newer style AC that has the glass bowel and a paper filter. I am not having any issues with fuel delivery or the engine stalling out. I have the 5/16 fuel line that is standard on my 39 Desoto. The Carter filter that has the ceramic filter was used as standard equipment back when these engines and cars were being run on a daily basis. Maybe the size of the picture is what is making you think the carter filter is not big enough to handle the fuel supply.

Rich Hartung

Desoto1939@aol.com

[DrDoctor]

To One And All - It looks as tho' I've generated some significant conversation, and that's a Good thing. All of this just reinforces my intent to relocate the canister filter from the front fender liner to the rear of the car near the fuel tank, where it probably should've been installed in the first place. So, I'm going to correct/improve some well-meaning person's installation at my first opportunity. I thank all of you for your valuable input. Thx.

[Don Coatney]

Rich, I stand corrected, you are right. I just checked the small glass bowl filter I have against a fuel pump and both have an 1/8" NPT hole. It appeared in the picture that the glass bowl filter was smaller.

 

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[dpollo]

Lots of conversation but the merits of pushing fuel outweigh the more traditional setups in that vapor lock ceases to be a problem . You can push fluids more effectively with a pump mounted in the fluid or very nearby.  No system pulls fuel anywhere.  The engine mounted pump creates a low pressure area and it is the atmosphere  which pushes the fuel along.  If the pump could create a complete vacuum then the atmosphere would have about a 15 pound advantage.   The pressure side of the pump then does the rest. A  fuel filter will work more effectively on the pressure side of the pump but in practical terms, especially if the tank is dirty, an in line filter can be placed between the pump and the tank.

[desoto1939]

DOn thanks for themupdated posting and the pictures of the fp and add on filter. that is basically what I have on my 39 Desoto.

 

Rich Hartung

[DrDoctor]

Wow!!!  I had no idea that my question would generate such great dialogue. Dpollo's correct about vacuum, and what it is, and what it isn't. To expound upon his initial thoughts - vacuum's a space devoid of matter. a vacuum, or "free space", is any space where the gaseous pressure is lower than atmospheric pressure. In quantum physics, even if all matter could be removed from a given space, it still wouldn't be totally empty due to vacuum fluctuations, dark energy, gamma rays, cosmic rays, neutrinos, and other such phenomena being present within that given space. now, whoda thunk that a question about a fuel pump would generate such thoughtful discours. is this great - or what? Thank you everyone!!!!

 

[dpollo]

I had my 50 Plymouth out today for a pretty good run.  I am just glad there are more than one of us left.  It is the vacuum between my ears that has me worried. 

[DrDoctor]

Yep, dpollo, there's at least a couple of us still around and kicking. And Yep, I'm a real doctor, albeit a retired one. So, (here's a long-distance diagnosis for you . . .) unless one can see light when looking into one of your ears, and you've definitely got something between your ears to block the light. so you're definitely OK. Thx.

[Niel Hoback]

What does it mean when I stand sideways in the wind and I hear whistling?

[Los_Control]

35 minutes ago, Niel Hoback said:

What does it mean when I stand sideways in the wind and I hear whistling?

Your fly is open?

[Niel Hoback]

Well,  that too.

[Plymouthy Adams]

could it be you are standing on a railroad track....

[DrDoctor]

Now that's funny!!! You guys are a riot. I'm sure glad all of you have a sense of humor, it makes life a lot more interesting, as shown here, and it makes it a lot more fun, too. Thx.

[maok]

12 hours ago, TheDoctor'sIn said:

Wow!!!  I had no idea that my question would generate such great dialogue. Dpollo's correct about vacuum, and what it is, and what it isn't. To expound upon his initial thoughts - vacuum's a space devoid of matter. a vacuum, or "free space", is any space where the gaseous pressure is lower than atmospheric pressure. In quantum physics, even if all matter could be removed from a given space, it still wouldn't be totally empty due to vacuum fluctuations, dark energy, gamma rays, cosmic rays, neutrinos, and other such phenomena being present within that given space. now, whoda thunk that a question about a fuel pump would generate such thoughtful discours. is this great - or what? Thank you everyone!!!!

 

Sorry Doctor, I have to pull you  up here.

 

Its not quantum 'physics', its quantum mechanics. They still have no idea what its about, a bit like me working on my '28....:)

[DrDoctor]

   Maok, you’re correct, up to a point. Quantum mechanics is also known as quantum physics, or quantum theory, or quantum field theory. It’s a fundamental branch of physics concerned with processes involving atoms and photons. Systems such as these which obey quantum mechanics can be in a quantum superposition of different states, unlike as in classical physics. Important applications of quantum theory include superconducting magnets, light-emitting diodes, transistors, semiconductors, and microprocessors. In my former field (medical), and research imaging, such applications would include lasers, magnetic resonance imaging, and electron microscopy, which yield explanations for many biological and physical phenomena.