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Can one of you gents please measure the OD of the top of a foot you may have laying around? I want to see if I can fit a 1/2” stainless hard line over it. I have a larger than stock pickup tube.
I have to go dig in my junk box because I’m a truck and boat part hoarder and think I tossed it in there. I’m at work away from my shop for a few days. I called TamerX Friday and asked the guy if he had one on hand to measure and of course he didn’t. He said he would email me if he found one...no dice!
Thanks
7/16” depending on the wall size. I remember the foot being tapered in that area.
Considering you are using the 6.7L fuel pump and larger lines, I’m not sure you want to go with that foot on the suction side.
Technically, the draw up to a pump is not done by the pump, a pump only provides negative pressure or a vacuum at the pump inlet. The movement of fluid to the pump is driven by atmospheric pressure. So the foot on the inside of your 1/2” tube would be a restriction that affects the volume of draw to the pump.
When I relocated the HFCM to behind the transfer case there really were two objectives. The obvious was to make it shower proof when bleeding water and changing filters. But the second was to provide better volume by reducing the more flow restrictive supply side. Think in terms of pond irrigation systems, you want the pump close to the pond for the best water flow.
In that vein, at the tank connections that you’ve eliminated, I also reamed out the metal tube ends that are rolled over to make a smooth transition for the quick connect fitting o-rings to glide on. You don’t have those, but just putting it out there.
I would check out what Ford did in the tank for the 6.7L if those stock lines are larger.
Thanks guys, I’m just weighing options and think I may go the direction you mentioned Jack. The 6.7 sending unit looks like it can be modified to retrofit to mine. The reason I want to do this is because I left the 1/2” tube about 1/4” shy of touching the bottom of my tank and when I get to the low fuel light level it will begin to suck air. It’s not a big deal but I really don’t need that issue and absolutely do not want to compromise my new injectors. I am not going with a sump at any time. I refuse to cut a hole in the bottom of my tank. I spoke in depth with the owner of Strictly Diesel and he has a whole list of reasons a sump is no better than a traditional top mount sending unit and the way the pump works with gravity feeding. The top mount sending unit actually puts less stress on the pump than the bottom mount sump.
The up-flow is almost balanced by the down-flow, it's not the huge restriction to come out of the top of the tank that people seem to think it is, IMO.
The problem you're experiencing is due to fuel slosh, more so than others as I'm sure you occasionally put the pedal to the test. Our tanks are wide open and while the foot draws very low, it doesn't work as well as a fully baffled tank or what is being used in the automotive industry right now gas and diesel, what I call a baffle pail. Here's an image from current Dodge diesel, look familiar? It's also what is in my 2003 Lincoln LS with saddle tanks.
We worked with Roush racing on some brake work, and I got to be with the team out at Elkhart Lake. I also spent months at Bill Stroppe's facility in when Bill was still alive (a lot of stories about that). In both types of racing, the tanks have extensive baffling. There is just nothing like that in the molded tanks we have.
Here is a YT simulation, but you have to go to 3 minutes in before you get a useful animation of what happens. There's probably a lot better ones on YT, and I'm sure Sean has some info from his aircraft studies. The fuel pail of the later fuel pickups is a good idea, IMO. Unless you drive like a grandpa, me. well, unless I'm in the LS, GT-350's or on the motorcycle.
The up-flow is almost balanced by the down-flow, it's not the huge restriction to come out of the top of the tank that people seem to think it is, IMO.
The problem you're experiencing is due to fuel slosh, more so than others as I'm sure you occasionally put the pedal to the test. Our tanks are wide open and while the foot draws very low, it doesn't work as well as a fully baffled tank or what is being used in the automotive industry right now gas and diesel, what I call a baffle pail. Here's an image from current Dodge diesel, look familiar? It's also what is in my 2003 Lincoln LS with saddle tanks.
We worked with Roush racing on some brake work, and I got to be with the team out at Elkhart Lake. I also spent months at Bill Stroppe's facility in when Bill was still alive (a lot of stories about that). In both types of racing, the tanks have extensive baffling. There is just nothing like that in the molded tanks we have.
Here is a YT simulation, but you have to go to 3 minutes in before you get a useful animation of what happens. There's probably a lot better ones on YT, and I'm sure Sean has some info from his aircraft studies. The fuel pail of the later fuel pickups is a good idea, IMO. Unless you drive like a grandpa, me. well, unless I'm in the LS, GT-350's or on the motorcycle.
Very interesting. That’s why I like this forum, we learn something new every day and usually by accident. That sending unit does look familiar...I think I’m ordering the Motorcraft 6.7 sending unit I just found new on eBay for $75 and it will be here Wednesday. The good thing is I have two extra fittings for that feed and return on top of the 6.7 unit! I like the design because it makes sure the pail is against the bottom of the tank with the long springs on the shafts and flex tubing to the bottom.
Here’s a photo a buddy sent of his 6.7 sending unit and fitting. He put a 6.0 in an F-100 and it has a 6.7L fuel pump and complete fuel tank.
I have the 6.7L fuel pump, I made the rest of my regulated return system, harness and everything.
Dropped the filthy tank and skid plate with 5 gallons of diesel left in it. Not a terribly bad job just 4 bolts and disconnect the fill tube. Sending unit Capped feed and return and drilled new holes Beefy 10AN bulkhead fittings with 1/2” hard line compression fittings Mounted pump and secondary filter between transfer case and rear axle Plumbed in Here’s where the HFCM used to be. It’s a good place for the relay and y splitter that goes from 1/2” to 3/8” and to the front of my heads. I went in reverse and my fuel goes in the front of the heads, comes out the rear, to my regulator and return to the tank.
The stock foot is also kept at the bottom of the tank. The accordion flare out to the screen area flexes with the bottom of the tank as it moves up and down due to the fuel weight. There should be a little compression needed when installing a stock sender into the tank.
The stock foot is also kept at the bottom of the tank. The accordion flare out to the screen area flexes with the bottom of the tank as it moves up and down due to the fuel weight. There should be a little compression needed when installing a stock sender into the tank.
I see that now, I wouldn’t have known because mine was in pieces when I removed it. Good to know!
Thank you Pete! I already ordered the 6.7 sending unit but if it doesn’t work out at least I know I can buy a $35 foot and use it with my current sending unit. If anything, maybe this will come up in a search if some other jackleg like me is modifying their unit.
I cancelled my order and have this foot on the way now that I know it will fit! Thanks again.
The other reason you may have noticed the issue is you changed the design of the fuel system. The way Racor designed the fuel delievery systems for International is to have a fuel flow system that allows air to return to the tank rather then be delivered to the fuel injectors. And there are two types of air, normal bubbles and released entranced air. You are probably aware of entrained air if you’ve read the detains of pumps like the Air Dog.
The stock fuel system returns air through the small hole in the top of the secondary filter, and the secondary fuel filter blocks air from going to the injectors. It does that to some extent with the secondary filter.
We ran into this when I was active with the 7.3L fuel system, and trying to solve the issue of crackle off the #7 injector. It was the original use of adding a remote fuel pressure regulator and also flowing fuel through the heads. The reason Racor and International do not flow through the heads is as stated in the Racor pdf, the head fuel rail becomes the “torturous path” as noted in the first paragraph of “the problem”. It can provide release of entrained air direct to the injectors. Altering flow from the back of the head to the front can alleviate some of the issue. It would take extensive testing with the right equipment to fully understand the issue. But a minor skip in a diesel would be hard to notice, just like an occasional misfire in a gas motor. OE is more concerned about skip and emissions then providing colder, dense fuel for performance.
International was aware of the crackle issue with the 7.3L and in the end used a different grade of injector to deal with #7 injector cackle. It was until a few years after when talking to a International engineer I understood the issue more clearly. If you pull 7.3L injectors after about 10-15k miles, you find a bathtub ring by the fuel inlets of the injector, a ring formed by the transition of fuel and air. The way the 7.3l heads are designed the fuel rails are under the fuel chamber of the injectors, and depending on the castings of the heads, these chambers can trap air as the injector fuel inlet is below the chamber roof. The operation of the injector can cause some frothing of fuel within the chamber. With the design of the 6.0, the fuel rail is above the head fuel chamber around the injector, so the fuel stays air bubble and froth free. It also means that the 6.0 can tolerate fuel flow through the head way better then the 7.3 can. So maybe in the end is me telling a story not needed to be told and I just waisted everyone’s time.
