Fuel - Fuel Pump Lines and Compression Fitting

[elspanishgeek]

In the process of torquing the Let-Lok Compression Fitting (https://breezeautomotive.com/shop/ef...n-adapter-kit/) to the instructed 1 + 1/4 turns to the 3/8'' line (https://breezeautomotive.com/shop/19...th-3-8-outlet/) I seemed to have collapsed the line. The fitting didn't look to end up square and I tried loosening it, making sure the starting point was correctly squared when everything is just finger tight, and re-torquing again. But I think this process is what ended up curving and flattening the line itself.

I sent Mark an email with the pictures but also wanted to check with the forum. Did I f*** up and need to replace the sender or is this fine?


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[JohnK]

I'm sure others more experienced than me will chime in, but that doesn't look ideal to me. That line will be somewhat restricted in its flow capacity and the compression fitting stands a good chance of leaking.

We all love to spend other peoples' money , so in that vein I'll suggest that you take a look at the Pro-M fuel pump hanger. Aside from the fact that it comes with 3/8" supply and return lines with -6 AN fittings already attached, it runs the return line all the way to the bottom of the tank so the returning fuel doesn't cause aeration.

[edwardb]

I've used those Let-Lok fittings a bunch of times on multiple builds and never had any issue with them. Certainly nothing like that. The spec you describe for tightening is correct. So I'm not sure what might have happened. Perhaps not on all the way before starting to tighten? But that's just a guess. I can tell you (from experience...) that once those are tightened they don't come off again. The compression ring inside gets sunk into the tube it's not going anywhere. I have no idea if that's a good connection or not. X2 on the Pro-M fuel pump hangar. I've used on all my builds except the very first one that was carb only and lower power. But that's a pretty big investment from where you're at now. Will be curious to hear what Mark says.

[Blitzboy54]

I am a bit of a compression fitting “expert” as I used them professionally in my early career. I started installing specialty gas systems and moved into micro chip manufacturing hardware. Compression fittings are a way of life in both those industries. I see 2 things here.

First is it doesn’t look square. It’s a bit **** eyed. If still fully tightened it should be even at the top and bottom. I suspect it is bent a little at the compression point.

2nd I think what happened is you may have gotten a little aggressive while tightening it. The connection is soft brass and assuming you used 2 wrenches it seems like you put more torque on the line than you meant to. The second wrench needs to counter the first but not create new torque. The line ended up flat and bent because it was pulled on while tightening I’m afraid. You can see it went out and to the left from the top down view. This exactly what I would expect it to see under these circumstances. That brass puts up no resistance. I think you need a new pickup I’m afraid.

[weendoggy]

If you're just connecting to AN fittings, why not just use EFI adapters that snap on the pump lines. They make them in 5/16" and 3/8" to 6AN, which would eliminate crushing/twisting and are easily removeable. Or, do as JohnK suggests and get the Pro-M. jmo

[elspanishgeek]

Mark replied that I can try bending the line back. I agree with the comments and this looks like I f***'d up. Expensive one at that. I can re-order the same parts from Breeze but now I'm thinking if this is an opportunity to go a different route. Here are the options I'm considering:

1) Pro-M Racing Fuel Pump Hanger with Aeromotive Stealth 340 Pump.
Seems like several people have gone this route. Have seen comments about having to modify the opening of the fuel tank, other say they didn't have to.

2) Aeromotive Stealth 340 Pump and Hanger.
Saves me having to put the hanger and pump together.

3) Holley Sniper 340 Pump Module
Another combo already put together.

4) 190LPH In-Tank Fuel Pump with the 1/4'' and 3/8'' to -6AN adapter kit
Repeat "The Breeze Combo" and perhaps not f*** it up this time.

I'm leaning towards Option 3. However, their instructions state that if running a carbureted engine, to use an -8AN line (1/2''), even though the flange has -6AN? I already did the plumbing with 3/8'' and a carbureted application needs less pressure so I'm not sure if this is a typo. Maybe I need to call or send an email. (In case anybody at this point thinks "why such overkill if you are using a carburetor?". I wanted to retain the option to upgrade to fuel injected in the future. This way the fuel system could handle it, lines, regulator, pump, is already in place.).

Anybody has any experience with Option 2 or 3? Particularly, do they fit the hole in the stock gas tank and don't bottom out? Also, I'm seeing both being recommended with a 30-amp relay, is this needed if I'm using the RF harness?

[rich grsc]

You don't say what engine you are running? A 340LPH pump will feed a 800+hp engine?

[elspanishgeek]

You don't say what engine you are running? A 340LPH pump will feed a 800+hp engine?

I got a 347 from BluePrint: https://www.factoryfiveengines.com/b...carbureted-mk4. So around 420 HP. Definitely more than the engine needs right now so I have an adjustable by-pass regulator from Holley.

[Blitzboy54]

Mark replied that I can try bending the line back. I agree with the comments and this looks like I f***'d up. Expensive one at that. I can re-order the same parts from Breeze but now I'm thinking if this is an opportunity to go a different route. Here are the options I'm considering:

1) Pro-M Racing Fuel Pump Hanger with Aeromotive Stealth 340 Pump.
Seems like several people have gone this route. Have seen comments about having to modify the opening of the fuel tank, other say they didn't have to.

2) Aeromotive Stealth 340 Pump and Hanger.
Saves me having to put the hanger and pump together.

3) Holley Sniper 340 Pump Module
Another combo already put together.

4) 190LPH In-Tank Fuel Pump with the 1/4'' and 3/8'' to -6AN adapter kit
Repeat "The Breeze Combo" and perhaps not f*** it up this time.

I'm leaning towards Option 3. However, their instructions state that if running a carbureted engine, to use an -8AN line (1/2''), even though the flange has -6AN? I already did the plumbing with 3/8'' and a carbureted application needs less pressure so I'm not sure if this is a typo. Maybe I need to call or send an email. (In case anybody at this point thinks "why such overkill if you are using a carburetor?". I wanted to retain the option to upgrade to fuel injected in the future. This way the fuel system could handle it, lines, regulator, pump, is already in place.).

Anybody has any experience with Option 2 or 3? Particularly, do they fit the hole in the stock gas tank and don't bottom out? Also, I'm seeing both being recommended with a 30-amp relay, is this needed if I'm using the RF harness?

Option 5 - Quantum Fuel

This is the hanger I used. Its much less expensive than the Pro-M model, it uses an 8AN fitting for the outlet but easy enough to get fittings from Amazon or whatever you prefer

https://www.highflowfuel.com/quantum...-without-pump/

[weendoggy]

Mark replied that I can try bending the line back. I agree with the comments and this looks like I f***'d up. Expensive one at that. I can re-order the same parts from Breeze but now I'm thinking if this is an opportunity to go a different route. Here are the options I'm considering:

3) Holley Sniper 340 Pump Module
Another combo already put together.



I'm leaning towards Option 3. However, their instructions state that if running a carbureted engine, to use an -8AN line (1/2''), even though the flange has -6AN? I already did the plumbing with 3/8'' and a carbureted application needs less pressure so I'm not sure if this is a typo. Maybe I need to call or send an email. (In case anybody at this point thinks "why such overkill if you are using a carburetor?". I wanted to retain the option to upgrade to fuel injected in the future. This way the fuel system could handle it, lines, regulator, pump, is already in place.).

That setup is more than enough and you can use both 6AN "O" ring fittings to keep both lines the same. That's more than enough. I have a 347/Terminator HP with stock 3/8" line, 255lph pump and have plenty of fuel.

[JohnK]

340lph is a LOT of pump for a ~400HP motor. More isn't necessarily better with fuel pumps. Anything that's not being used is getting recirculated back to the tank, so with a larger pump you're just recirculating a lot more fuel, causing heat buildup and aeration. I have a 255lph Walbro on my gen 2 coyote (435HP) and that's plenty of pump for an engine of that HP.

[elspanishgeek]

340lph is a LOT of pump for a ~400HP motor. More isn't necessarily better with fuel pumps. Anything that's not being used is getting recirculated back to the tank, so with a larger pump you're just recirculating a lot more fuel, causing heat buildup and aeration. I have a 255lph Walbro on my gen 2 coyote (435HP) and that's plenty of pump for an engine of that HP.

I'm trying to avoid assembling the pump and the hanger myself, and anything that requires modifying the fuel tank itself, unfortunately, the combo options I'm finding are with 340LPH. Anybody knows of a complete kit that fits the FFR stock fuel tank (I believe it's a Fox Body Mustang '83-'97)?

I guess another option is to just get the Pro-M hanger, take out the 190LPH Walbro pump from the busted hanger and mount it on this one.

[JohnK]

Honestly, installing a fuel pump in a hanger isn't that complicated. You'll need some crimp connectors with fuel-resistant heat shrink. A quick forum search will turn up the correct P/N's (I think Edwardb identifies them in his roadster build thread) or I may have them in my purchase log if you can't ID them. If you're building one of these cars, you can install the pump in the hanger.

Edit: as far as modifying the tank, I know the Pro-M instructions say to cut a notch to fit the hanger. I wasn't crazy about doing that either (or more accurately, I wasn't crazy about having to clean out all the metal filings after I'd done it) so I tried to install it without cutting the tank and it worked fine. I know of several other people that have also installed it without cutting the tank. It's tight and you need to make sure you don't accidentally nick the wires on the sharp metal edges but It's doable, IMO.

[elspanishgeek]

Honestly, installing a fuel pump in a hanger isn't that complicated. You'll need some crimp connectors with fuel-resistant heat shrink. A quick forum search will turn up the correct P/N's (I think Edwardb identifies them in his roadster build thread) or I may have them in my purchase log if you can't ID them. If you're building one of these cars, you can install the pump in the hanger.

You sold me. Getting the Pro-M Racing hanger. Thanks for taking the time to help me out!