Lift pumps

[gmc502]

I'm curious as to where the air comes from :roflmao:

IMHO its out of necessity because they return so much fuel and create a foam in the tank. But hey, I'm just a regular idiot

If the pickup is submerged in fuel, you have no leaks, and the supply is under pressure, how would air enter the fuel?

the plastic tube,,I noticed mine could be twisted on the barbs.So anything less than a full tank and the path of least resistance,,draw in some air.
I revamped my pickup w/ bulkhead "an" fittings and 5/8" line to a billet pick up.
I'll see if I can find some pics of my set up.

 

[gmc502]

heres my set up.

 

[DMAXchris]

I'm curious as to where the air comes from :roflmao:

IMHO its out of necessity because they return so much fuel and create a foam in the tank. But hey, I'm just a regular idiot

If the pickup is submerged in fuel, you have no leaks, and the supply is under pressure, how would air enter the fuel?

The air comes from the fuel. Diesel fuel traps air, which is known as cavitation. It occurs from the fuel sloshing around in the tank. If you could see your fuel, it has millions of tiny air bubbles trapped in it. Removing that air allows the cp3 and injectors to work better. I was Mr. Anti-airdog for years until i saw how it worked in person.

I'd go FASS or Kennedy. Air dogs customer service blows

I have had the opposite experience. They always take care of me. Im on my 3rd pump, and all have been replaced under warranty.

 

[c20elephant]

The air comes from the fuel. Diesel fuel traps air, which is known as cavitation. It occurs from the fuel sloshing around in the tank. If you could see your fuel, it has millions of tiny air bubbles trapped in it. Removing that air allows the cp3 and injectors to work better. I was Mr. Anti-airdog for years until i saw how it worked in person.


I have had the opposite experience. They always take care of me. Im on my 3rd pump, and all have been replaced under warranty.

May want to look up the word cavitation, entrained air in the diesel fuel is the word you're looking for....

http://en.wikipedia.org/wiki/Cavitation


Cavitation is the formation of vapour cavities in a liquid – i.e. small liquid-cavitation-free zones ("bubbles" or "voids") – that are the consequence of cavitational forces acting upon the cavitational liquid. It usually occurs when a liquid is subjected to rapid changes of pressure that cause the formation of cavities where the pressure is relatively low. When subjected to higher pressure, the voids implode and can generate an intense shockwave.

http://www.parker.com/literature/Racor/Mobile_Air_Separation_In_Diesel_Fuel.pdf

 

[DMAXchris]

Yep that too. Wouldnt cavitation occur when the pressure changes at the CP3? Airdog uses the word themselves in their explanation of the system, which is why I said it as well. Cavitation becomes less prevalant when there is positive supply pressure. If a pump like the Kennedy aquarium pumps only produce 4 psi, you lose that pressure when the cp3 is maxed out and cavitation could occur.
http://www.pureflowairdog.com/how-airdog-works.php

 

[c20elephant]

If your CP3 is sucking more fuel than the pump can supply cavitation occurs, same goes for the AirDog/FASS trying to suck from a 3/8 supply at the pickup and exiting a 1/2 line, I understand the dynamics but have difficulty writing it..

 

[c20elephant]

heres my set up.

You added a 1/2" fitting for the vent in the tank, that'll keep your filler neck from spitting back at you rather than using the 3/8 former supply for the vent and looks like you installed the return from the pump directly to the tank as opposed to cutting the filler hose...:thumb:

Correct?
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[Huffy67]

I've been using my air dog 150 with draw straw for a couple years and have zero complaints!!!


Sent from my iPhone using Tapatalk

 

[PureHybrid]

On the LLY trucks, you switch over to the 5/8 vent line and use that for the supply from the pickup tube upgrade for pump supply. And use the old feed line for fuel return.

I've seen the FASS "demo" at a show where air magically enters the supply line and it'll purge it from the outlet. Still snake oil if you ask me.

If air truly makes it past the pump and is cavitating my cp3, how is it still alive after 215k miles?

 

[gmc502]

You added a 1/2" fitting for the vent in the tank, that'll keep your filler neck from spitting back at you rather than using the 3/8 former supply for the vent and looks like you installed the return from the pump directly to the tank as opposed to cutting the filler hose...:thumb:

Correct?
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correct,I also ripped the guts out of the filler neck,now I can go to the big boy filler nozzle.added a 5/8" vent tube to the top section of the filler neck.I got that from another tank mount set up I had laying around.

 

[DMAXchris]

On the LLY trucks, you switch over to the 5/8 vent line and use that for the supply from the pickup tube upgrade for pump supply. And use the old feed line for fuel return.

I've seen the FASS "demo" at a show where air magically enters the supply line and it'll purge it from the outlet. Still snake oil if you ask me.

If air truly makes it past the pump and is cavitating my cp3, how is it still alive after 215k miles?

Air doesnt "magically" enter the line. Its already in the fuel. Pour some #2 in a glass jar and look at it. Then shake it up. Watch how long the foam sits on the top. Its not snake oil. Its fluid dynamics. You have 2 aquarium pumps, so your pressure prob doesnt go negative with stock injectors. When a fluid is compressed, the air still remains in the lines, so you have 26k psi of air & fuel mixture going to your injectors.
Stock tuning isnt taxing the pump, which doesnt cause a loss of pressure.

 

[Bonestock]

I'd go FASS or Kennedy. Air dogs customer service blows

Man I disagree. I have had airdogs fail and you call them with a motor # no questions asked and they will ship one out to ya.

Fass wont stand behind their product whatsover if the warranty card wasnt filled out and sent in to them in first 30 days. I don't mean to bust your Wyoming ballz just telling it like it is lol!

 

[minerigger]

Haha no offense taken

 

[Bonestock]

Haha no offense taken

Haha cool deal.

 

[PureHybrid]

Air doesnt "magically" enter the line. Its already in the fuel. Pour some #2 in a glass jar and look at it. Then shake it up. Watch how long the foam sits on the top. Its not snake oil. Its fluid dynamics. You have 2 aquarium pumps, so your pressure prob doesnt go negative with stock injectors. When a fluid is compressed, the air still remains in the lines, so you have 26k psi of air & fuel mixture going to your injectors.
Stock tuning isnt taxing the pump, which doesnt cause a loss of pressure.

Yea, you said "shake up". Which doesn't happen unless you drive on a motocross track. And then the foam "sits on top", who cares what's on top? I've yet to see a video disproving that by simply having positive pressure the fuel system cannot purge itself of air. Let's see a demonstration of a simple vane pump (Kennedy or not) spitting out all these air bubbles you speak of.

 

[DMAXchris]

Yea, you said "shake up". Which doesn't happen unless you drive on a motocross track. And then the foam "sits on top", who cares what's on top? I've yet to see a video disproving that by simply having positive pressure the fuel system cannot purge itself of air. Let's see a demonstration of a simple vane pump (Kennedy or not) spitting out all these air bubbles you speak of.

So you think the fuel sits still in your tank when you drive down the road? :spit::rofl::roflmao: What about the return line pissing fuel back into the tank? Do you think that causes bubbles? There is air present in the fuel ALL OF THE TIME. Believe me or not, its true.

 

[OregonDMAX]

Pull off your fuel return line or airdog return line, its not even fuel its just foam. That's proof enough there is more air then fuel returning to the tank.

 

[gmc502]

If your getting alot of air,you need to look at the clear tube in the tank's connections.I have a vac gauge on my serdi machine,I tested mine and it was not pulling full vacuum.Thats why I replaced mine with an air tight system.
Must be doing something,,I've had an injector going since 272k and its not gotten worse.I'm now at 306k,till the same.
And I don't run any additives.

 

[PureHybrid]

So you think the fuel sits still in your tank when you drive down the road? :spit::rofl::roflmao: What about the return line pissing fuel back into the tank? Do you think that causes bubbles? There is air present in the fuel ALL OF THE TIME. Believe me or not, its true.

Not saying that at all. And yes, there is naturally air in fuel too.

But what you, FASS and Airdog lead the public to believe is there are giant air bubbles being drawn into the system. While I'm sure their systems are capable of purging such air, there is still entrained air in the fuel. You can't see it when the fuel is under pressure. So for all we know these air separation systems don't work in that aspect. Maybe you need to read that parker article you quoted again.

 

[c20elephant]

If your getting alot of air,you need to look at the clear tube in the tank's connections.I have a vac gauge on my serdi machine,I tested mine and it was not pulling full vacuum.Thats why I replaced mine with an air tight system.
Must be doing something,,I've had an injector going since 272k and its not gotten worse.I'm now at 306k,till the same.
And I don't run any additives.

Did you seal the port on the sending/pickup head that would act as an atmospheric vent, the one marked old supply in my picture?