Probably with an AirDog.

https://fassride.com/shop/product/fu...-0l-1999-2007/

 

I have seen the air dogs. Unfortunately they are really expensive and I was looking for the reliability of a stock truck that’s why I want to go with 2 oem pumps. Also those pumps are usually pretty loud. But that might be the only option. Is anyone using the 4 line feed with the bowl delete?

 

You'll have to get creative to get a regulated return to work with the 4-line feed then.

 

how will you plumb your dual pumps ?

series or parallel ?

describe your plans for the whole system starting at the tank. why 2 micron ?

besides no part of the 7.3 needing that level of filtration the replacement cycle becomes costly and tedious.

my thoughts about “easier to work on and leaks”

the stock system is pretty “easy” to work on, once you start modifying it my experience says that the more changes you make the further you get from it being simple or easy to work on since you are more then likely adding new issues that need to be resolved. stock is simple to work on especially since the system is supported by factory documentation.

leaks, super easy to resolve. rebuild the fuel bowl with quality O rings from www.dieselorings.com

a simple and easy upgrade to make the stock system more robust is the billet fuel pressure replacement they make. the stock on is prone to stripe the threads.

 

Okay so at the fuel tank I will be removing the mixing chambers and extending the return to the opposite end of the tank. Pretty much the hutch and harpoon mods in tank. I am also going to be installing a 5/8 draw straw. From there I’m going 5/8 line to a water separator pre pump filter. The micron rating on that escapes my mind but I think they are around 40 micron. From there I’m going into 2 oem pumps mounted parallel with 3/8 fuel line between 2 pumps and pre/post pump filters. After the pumps I will have check valves in line. Then a post pump 2 micron filter. This will all be fabed up to a custom mount. My brother is a welder and has a shop so he will help me in the morning department I’m sure it will look good. From there it will go 1/2 fuel line up to the engine. This is where I’m at currently as I’m trying to decide on the 4 line feed or not. And I will also run a new 3/8 return line. My filters will both be wrapped in a 100 or 200 watt pad heater wired to a toggle so I can turn them on in the winter to make sure I don’t have gelling problems. That’s my whole fuel system vision but I am doing up pipes soon so I’m trying to do the top half first because it will be easy to get to when I have the up pipes out.

 

sounds like you have a decent starting plan, be sure to post progress pics and results.

 

I will. Hopefully first I can find someone who has the 4 line feed and deleted bowl to tell me how they keep the air out.

 

they dont. thats the problem.

air is naturally in diesel fuel. google “entrained air diesel fuel” and study up

the best you can do is locate an air trap that allows it to escape as close to the injectors and as the high point in the entire fuel system as possible. difficult to beat the stock location for this.

you see guys but s Air Dog system on the frame rail but that is the least effective place of all.

any entrained air that comes out of suspension between the air dog and the heads is subject to go through the injectors.

improving on the stock fuel bowl air trap is.... difficult at best. like i mentioned, if you do achieve that goal you are likely going to end up with more clutter up in the engine valley then you started with. stock air trap is simple and effective.

 

there are engineering degrees devoted to the field of fluid dynamics and entire books on the subject of race car plumbing so you fo have resources to draw from but for the most part you are out in the weeds to figure out and resolve the issues present but it is doable.


summary is, every fitting and bend has the potential to create turbulence or pressure change, you are relying on pressure to keep the air entrained in the fuel. create a pressure differential and the air comes out of suspension.
think twisting the lid off a coke bottle, you created a pressure differential and the CO2 comes fizzing out of suspension.

more flow also equals more opportunities for air to come out of suspension snd it will also mix more fuel into the full when it returns into the tank, so be sure to deal with that, a baffled fuel cell with a mixing chamber is a good idea to let the air separate

ford ( and others ). use the dead head for this very reason. they could have very easily done a flow through system to combat the #8 feed issue, but developing the long lead injector was a better solution. ( that should give you a hint at the difficulty of the challenge of dealing with entrained air )

having excess fuel flow above what the injectors require creates more problems then any perceived gain so carefully match the flow to the actual usage to minimize the amount of air you need to deal with removing.

anyhow, that should point you in a helpful direction while you are engineering your own fuel system.

 

Is it the stock bowl that helps with getting air out or the stock filter? I’m wondering if maybe I kept my whole pre engine plan and used the 4 line feed with the stock bowl. But then I just put a filter cap on it with no filter since the fuel will be good already from the post pump filter. That would maybe help with the air part but then the valley is still cluttered.

 

i sorta already answered this indirectly but will repeat so you can apply it to this specific question.

it is the entire system.

The system is designed with a overall goal in mind, . there is not a single part that has not been carefully designed to meet that goal. if you remove or alter one element you have moved away from the stock design. the physics of fluid dynamics dictates the design which for those designing a fluid transfer system means if you change one element to gain something you will have to deal with the loss of another element. the trick is find the right balance or compromise to get to your goal.

to specifically answer your question go study filtration and its effects on fluid, filtering down to 2 microns is a gain in clean fuel supply to be sure but the there is a loss of another element that is equal to the gain.

off the top of my head i do not recall the stock filters micron rating. but from experience i can assure you filtering down to 2 microns is not something needed by any component in the 7.3, ford put the correct rated filter in the best place for the overall design goal , you can
certainly alter it to meet your needs but since you have not shared your goal other then to clean up the engine bay its difficult to speculate,

one thing I will mention, dual parallel pumps with check valves has high turbulence potential. i have done it but not for a application like you are. a dingle pump with the desired dpecs is the solution i would prefer . i only uses dual parallel pumps for redundancy in race applications, that was if a pump dies you flip a switch and fire up the other pump. the check valves And y fittings are not something i want to flow through down stream.

 

I hear you out on the turbulence but that is why I am thinking 1/2 fuel line. That’s plenty of fuel I’m sure more than 238s will need. So I’m hoping with the bigger feed line that I won’t need to worry about the turbulence part of it. I definitely need to do some thinking on the air part still though. I’m thinking I start with the 4 line feed and in tank mods because that would only help the air in the fuel. Then from there I will hook up a psi gauge in cab so I can see what my pressures are like.

 

@vgk What are you planning to use the truck for? Tow pig, sled puller, drag racer, etc?

 

I tow a lot with this truck but when I get to the point that I’m ready for big injectors I would use it for a daily more and probably be racing some in it. The truck was my first vehicle and I won’t ever get rid of it because of that. So what I use it for will change as I get other trucks as well. So that being said the current use is work, towing and having fun in it because I love these trucks.

 

Another question, doesnt the stock fuel system have check valves in the head? Are those deleted with the 4 line feed?