Ok guys this is the one that I want to share with you all because it's easily constructed from over the counter parts and it will work perfectly for getting rid of all the air in the fuel rails. I've been thinking about how to get this done since I did this project last year. I never liked how big the oriface was in the first attempt. Too much fuel was being bled off. The fuel pump had to keep up with that extra volume and still provide the right amount of fuel to the engine. This new design will directly address that issue. The old oriface size was .45 mm - at least twice the size that I felt was necessary. I don't know the size of the new oriface but I would hazard a guess at somewhere between .15-.20mm.
First of all see this thread:
https://www.ford-trucks.com/forums/s...d.php?t=260173
It details the start of this journey on trying to get rid of all the air that gets trapped inside the fuel rails on our 99 -03 7.3's. By design once air gets in there it's only way out is through the fuel injectors. Dumb idea.
Ok. Go out to your local hardware store and get yourself a propane torch oriface and nozzle kit.
https://www.ford-trucks.com/user_gal...oid=99189&.jpg
The back side of the package.
https://www.ford-trucks.com/user_gal...oid=99190&.jpg

While you are there, gather the following NPT fittings. Two female 1/4" NPT threaded with 1/4" barb fittings on the other side.
One 1/4" NPT double male fitting.
One 1/8" NPT plug fitting with a female allen.
One 10x32 machine screw tap to make the threads for the propane oriface.
One 1/8" NPT tap.
Some fuel rated yellow thread tape.
https://www.ford-trucks.com/user_gal...oid=99191&.jpg

You begin by taking the 1/4" double fitting and tapping out one end with the 1/8" NPT tap. Apologies for the out of focus, but it should get the idea across.
https://www.ford-trucks.com/user_gal...oid=99192&.jpg

Ok, take the 1/8" NPT plug and install it into the threads that you just made.


From there you need to drill and tap the little 1/8" NPT plug right down the center with the 10x32 machine screw tap. Once that's done remove the 1/8" NPT plug from the 1/4" NPT fitting. Take the oriface fitting and remove the little filter from the end of it. It's pressed into the oriface fitting, but not so hard that a firm gentle pressure with some pliers at each end wont pull it out. It's easier than it sounds right here. Just grab each end and give it a twist and pull. Remove the tiny little rubber o-ring from the shoulder of the oriface fitting and discard. Screw the oriface fitting into the side opposite the female allen on the 1/8" plug. You'll end up with this:


Here's a view of how it will be installed in the fitting:
https://www.ford-trucks.com/user_gal...oid=99194&.jpg

Ok, now take the 1/8" allen plug and install it into the 1/4" fitting that you cut the threads into. Then re-insert the little filter that you removed from the backside of the oriface fitting and you'll end up with this:


From there, it's basically wrapping the male threads with fuel rated thread tape and installing the barb fittings.
https://www.ford-trucks.com/user_gal...oid=99197&.jpg

After you get it assembled, put some arrows on it so you don't accidentally install it backwards.
https://www.ford-trucks.com/user_gal...oid=99198&.jpg

I plan on simply splicing this assembly into the return line just downstream of my existing tee fitting which will have the old oriface removed.

Merry Christmas to all at FTE!

 

http://www.mcnallyinstitute.com/13-html/13-12.htm

describes the equations to determine flow through an orifice - If you have questions PM me. We'll work out what's going on. David

 

Do have a any pics of the install into the engine

 

DVW70, thanks for the offer. Honestly I wouldn't know what to do with the numbers. Math was one of my worst subjects in school.
I got the oriface idea from the design of Bosch K-jetronic fuel injection. They use a .2mm oriface for the fuel pump to pump against. I extended that idea to include the removal of any air bubbles that may get trapped in the fuel rails of out cylinder heads.
I chose the .2mm size because that's the size that they use.
Believe me I'm no scientist.
I'll post a picture once I get it installed. Right now it's sitting in a drawer.

 

Kwik

I'm currious why you are going through all the trouble to build this bleed oriface rather than just putting together a regulated return system?

 

Enlighten me & for those of us that are new here... what are the advantages of getting the air out ?

 

Air destroys injectors overtime and robs power and economy..

 

I'd guess about $300 difference in cost which he gets to spend on other goodies, and the pride of knowing he's solved the problem for himself. It may not only be cheaper, but better. It has no "active" parts, thus may end up more reliable in the long run.

It isn't a tenth the "trouble" that Hutchinagusta went through to find out about the suction air leaks that occur behind the fuel pump and solve them, but the results are both about the same benefit to us.

Pop

 

OK, I can see that. But really the only price diference is the price of the regulator itself... he already had to have all the same hoses and fitting for what he has put together. All the parts for my regulated return came to $160... I understand the pride of "doing it yourself" that's why I didn't pay $400 for $160 worth of parts.

Eric

 

Otter,

You are, of course, completely correct. Now I understand your question a lot better. And, yes, ain't it grand to know you can do the same thing a LOT cheaper?

Where did you buy the regulator? What brand and model number are you using? I ask because this is one of the things I really want to accomplish this year, and I can lean either way on using the factory regulator or going aftermarket. If the price is right, I may opt for the finer pressure control I'd have with the aftermarket.

Pop

 

Yeah it was the price. I still think that a full regulated system would be the best route, but this saved me $300.00+ and works just as well.
Also I have the opinion that a full regulated system would need a much larger fuel filter than the stocker.
The way that Ford designed it the only fuel that gets filtered is what gets used by the injectors. The pressure regulator/fuel return is on the outside of the filter. All the excess fuel simply goes back to the tank. If you route ALL the fuel that the pump delivers to the pressure regulator than you are increasing 100 fold (just a guess) the amount that the fuel filter has to filter.
With my little oriface the amount is increased but not by nearly so much.

 

I like your engineering Kwik. Cheap and it works.


formerly BUICKTURBO

 

Kwik,

In the long run, though, eventually ALL the crud that enters your fuel tanks will HAVE to be filtered out of the fuel. Sooner or later. Even that crap that you think is destined to stay on the bottom of the aux tank will get picked up somehow.

The way to have the cleanest fuel is to continually filter and return to the tank, using only what's needed along the way. Since the pump's wear isn't very dependant on the volume it pumps, but the time it's been in service, I would think that recirculating a lot of fuel just keeps it all the cleaner.

I prefer to catch as much as possible in a large two-micron pre-pump filter, and I sure don't mind how many times an individual molecule passes through it before it's diverted off to an injector. Once you get a large one installed pre-pump, you'll think less about the recirculated volume, as it won't really matter (at least to a point). The stock filter will stay reasonably clean, too.

Hey, I just thought of a use for your old pump. Hook it up to simply recirculate fuel through a bypass fuel filter!

OK, overkill....... but still fits the thinking mold around FTE!

Pop

 

Pop

I'll be using a reg made by Kirban... 0-100psi. Nice thing is it comes with all the fittings. (about $30 extra if you use the SX or aeromotive) And it's the only one rated to the right pressure out of the box. I paid about $90 for it NIB on Ebay. I've had all the parts sitting here for about a month and a half but haven't had the time to get it put in. Maybe this afternoon.

Eric

 

Hey finally a vendor I'm familiar with!!!!

www.kirbanperformance.com

Formerly,
BUICKTURBO