I'll just leave this here:

https://www.ford-trucks.com/forums/6...completed.html

All the pictures have gone AWOL. I'll have to dig those up.

 

maybe i missed it but is there a thread or discussion that covers why he did it or what specifically he was trying to solve or accomplish ?

the in tank vrs external pump debate has been around as long as internal combustion engines themselves. each design has pros and cons and it comes down to picking which one best suits your needs.

for me, access and serviceability is paramount so external has been my choice in both my 7.3 vehicles and the systems i have designed and built from scratch for other applications. however in take systems have their place.

 

I would be interested in pics, but just reading the first few posts I see where you achieved the desired results - while apparently starving the pump based on your ‘fix’ a few posts down....

This was an era where folks were adding 2mic pre-pump filters and starving the stock pump so they were adding ANOTHER pump which was generally a restriction to the first pump. All with no in-cab fuel pressure gauge to actually quantify if anything they did made an ‘improvement’.

I don’t mean to be critical of your choices, but during that time I felt like the forums were creating lemmings doing ‘mods’ because there was a grain of ‘that makes sense’ in the theory.

Who remembers TAG and zoodad mods?? This was very popular until the turbos injested a few TAG’s and people figured out the zoodad just makes filter dirtier and WET and neither mod has any measurable benefit, but has some serious negatives.

 

@pirate4x4_camo He was trying to eliminate air suckage through the QD fittings by placing them under positive pressure. That was my original motivation to put the pump in the tank but it’s moot now since I’ve changed everything to AN/JIC. I will probably relocate the pump to the frame rail the next time I have to replace it.

@SkySkiJason Yup, fully agree with your assessment with that era of mods. The pump got starved because the filter gelled up in winter. That led me to add a coolant powered fuel heater. Unnecessary complication heaped on unnecessary complication. I came to find out that Bosch pump has its own intake screen so the filter was redundant anyway.

 

From your thread.


People STILL believe this is true. Smart people who are very talented fabricators. Most have never actually seen this alleged problem.

I was doing some very different experimenting with fuel system mods. My truck has 250k miles on vegetable oil now. It was a test bed for a fuel system design that is being used by 1000’s of successful VO conversions on the road today. This experience has brought me to some very different conclusions than the common ‘parrot talk’ that many forum members regurgitate in an effort to be helpful to newbies.

 

All that VO talk, makes me want to put another system together and get anutha 150k outta her in 4yrs

 

That screen is TINY and while it may keep the pump from injesting a pine needle or something that fell in the tank - it doesn’t take much to stop it up.

The pre-pump filters like WIX 33972 have more capacity for debris and putting it in a serviceable location (not in the tank) is a good idea.

 

GITRDUN!!!!


I always tell people I can quit anytime I want.....

I also put 120k greasy smile miles on my Excursion.

My truck only accumulated 5k miles last year, but I drove this veggie truck 10k miles for ‘testing’.

 

Almost every hutch mod I see people put the pickup tube 1/2 to 1/4 inch above the bottom. But you bend a 90 so it’s basically resting on the bottom right? I’m sure either way works fine. I’m thinking 1/2 off the bottom is what I will do only because I don’t think I want my tube resting right on the bottom where it could wear

 

Ummm, the screen in a Bosch 044 runs the entire diameter of the pump.

 

You MUST put the pickup tube a little off the bottom of it is straight cut - or it would be obstructed by the tank bottom.

If you hold the vacuum cleaner hose 1/2” above the floor, it will suck dirt off the floor, right? What about from 6” high? Not so much..,

Just off the bottom is fine. Now the guys who hold the umbrella off the bottom - not a good idea. The umbrella was meant to sit on the tank bottom. The space built into the bottom of umbrella (the screen does not touch the tank bottom) is sized to allow unobstructed flow by spreading out the area fuel is drawn from. That space is equal to more square inches than the 3/8” tubing. I hope that communicates what I’m trying to say....

Again, it is critical that fuel is drawn off the bottom of the tank to prevent an accumulation of water/debris in the tank. I feel like y’all are confusing a primary fuel tank with a storage or transfer tank. On the latter, you absolutely do not want to suck ‘off the bottom’ because you want that space to collect condensation/rust/etc. In your truck, you want to go to extreme measures to never put anything nasty in your fuel tank to start with and if you do - the filters are there to prevent damage.

Holding the suction off the bottom DOES NOT prevent water or debris from getting into the pickup. Your tank is constantly being mixed by sloshing and the pump return. But, holding off the bottom can allow stuff to accumulate in the tank with no way to remove it besides dropping the tank.

Most people could probably get away with no fuel filter for a looooooomg time. We are very fortunate to have a great fuel delivery system in this country as well as government oversight and direct accountability for damage and inconvenience in the event you get ‘bad fuel’. I would argue that very few people if anyone uses fuel pressure (or vacuum) as a metric to decide when their filters need changed. They just change them on-schedule ‘because that’s the right thing to do’.

I decided that it was better to put a 90* bend on the bottom of pickup tube so I could get CLOSER to the bottom of the tank than 1/4 - 1/2”. I avoid touching the tank bottom, but unless the tubing was being pressed into the tank bottom - there is zero concern about ‘wear’.

Overall, I settled on this design a looooong time ago because it is consistent with the K.I.S.S. method that is my personal mantra. Less is often more in the big picture.

 

Thanks. What your sayin about the pickup umbrella definitely makes sense. I think I’m going to remove the pickup umbrella and just mount the pickup 1/2 Ian inch above the bottom of the tank. Thanks everyone for the reply’s. When I start work on this truck I will keep you updated and if I have any more questions I will be sure to ask. It’s awesome how many replies I got.

 

The pictures have been restored.
https://www.ford-trucks.com/forums/6...ml#post5537890

 

Thanks for the pictures

 

thanks for the pics, i will go back and study when i get to my desktop to see detail, always curios.

i dont want to derail this tread with the in tank vrs external debate ( although not being a engineering oriented site we might not end up down that rabbit hole ) i am not aware of issues that give in tank much advantage with diesel. gasoline is a whole different story because of the additives in modern day fuels.