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Discussion Starter #1
Hey guys,
So, putting together a shopping cart for bits to get my 5.0 conversion some go juice. I already have a Walbro GSL392 which I plan on using.

The bit that has me running circles is all the bits in between. Here's what I am currently thinking -

* Run EFI hose and clamps (Vaporguard?) from sender to pre filter (presuming 5/16" as this is what the original sender outlet is? Does this need to be 3/8" before the filter?)
* Run EFI hose and clamps from pre filter to pump inlet
* Run EFI hose with an adapter to a 10 u post filter with 6AN inlet/outlet
* Run 6AN PTFE braided hose all the way to the supply rail with an 6AN adapter down the length of the car

And on the return -

* Run PTFE from the return on the fuel rail using a 6AN adapter there, and flare the return line and use an AN fitting (So it matches under the engine bay)
* Plumb this into the drain of the fuel tank at the rear using some of the EFI hose and clamps

Can anyone see any problems with what I am thinking? I've never done a project like this before and have read so many different posts and seen there is a million ways to do this.

Open to suggestions!

-Rob
 

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I can see lots of problems. #1 you want hard lines wherever possible, secured to the chassis. Steel or nylon. Use flexible line only for connections where movement/vibration is a factor (between chassis & engine) or where it facilitates the removal/installation of a component (filter housing, pump, sender, etc.).

Use an EFI-specific fuel tank making sure the fuel lines are isolated from the passenger compartment.

Do not install a "pre-filter" between the tank and pump. If you've used a decent "sock" on the inlet on a new tank you needn't worry. Just make sure you use an axial pump and not some cheap piston/diaphragm unit.

Make sure the fuel pump circuit is properly fed, grounded and circuit protected and that you have redundant shut-off's in place (pendulum switch, rpm trigger, oil pressure switch, etc.).
 

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I ran two -8 braided stainless PTFE lines from the tank to the fuel rails. There is an inline filter on one of the lines. I initially wanted to run hard lines but then thought about all the extra connections that it would take to make it work. (Two more connections on each hose). To me, connection points are just another opportunity for leaks. One of the downsides to running the braided stainless line is that you have to attach more support clips though. Just my two cents.
 

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Why not use the factory fuel line for the return, there isn't much pressure in it and with some EFI rated hose and clamps that would at least save some trouble of routing/bending lines and look tidy in the process. How much HP? If you want to push it, 3/8 will probably work better to feed an external pump, if it's a relatively stock engine then the 5/16 should be ok.
 

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All the TBI EFI systems require 3/8in for pressure/feed. Classic tube makes some nice pre bent 3/8ths steel lines. If you're set on making less connections, you could run the 3/8ths vaporguard the whole way. You'll just have to add some clamps and mounts

The 5/16ths will cause issues for feeding them. But it is great as a return line. You can use EFI rated fuel hose with the good little clamps on the return. Its very low pressure.
 

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I ran two NEW earls vapor guard Efi hoses (3/8s and 5/16ths) to my spectra tank (has stock connection location) with no issue and very easy. I hose clamped them together every 12 inches to the body - up over the rear axle (added the fuel filter near the tank connection), through the trans / axel tunnel, up against the passenger fire wall, and right to the sniper.

very very minor sag after they got filled with fuel, but other than that - worked out great. its been a year, and they haven't moved at all and no leaks.

i also installed fuel pressure gauges in the engine bay (on both)



I thought about using the factory fuel line for the return, but I wanted to keep the fuel lines together going out the back, vs one going backwards, and then one snaking around the front of the motor and to the driver wheel well (like the factory line did)
 

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Discussion Starter #8
Its funny how the simplest things can get us hung up sometimes. So, my original fuel outlet tube from the pickup on the tank is 5/16" (I believe)... to get from that using a 3/8" line like a Vaporguard, how would I attach the end of the hose to the fuel outlet tube? Obviously there is different sizes at play. Can I just clamp the 3/8" hose onto it? Do I need to put some sort of fitting on it? This is probably the bit that has the biggest question mark in my brain as to how to make it work, as the rest of the system I can use a collection of fittings etc to make it all fit.

-Rob
 

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I ran two NEW earls vapor guard Efi hoses (3/8s and 5/16ths) to my spectra tank (has stock connection location) with no issue and very easy. I hose clamped them together every 12 inches to the body - up over the rear axle (added the fuel filter near the tank connection), through the trans / axel tunnel, up against the passenger fire wall, and right to the sniper.

very very minor sag after they got filled with fuel, but other than that - worked out great. its been a year, and they haven't moved at all and no leaks.

i also installed fuel pressure gauges in the engine bay (on both)

-Image-

I thought about using the factory fuel line for the return, but I wanted to keep the fuel lines together going out the back, vs one going backwards, and then one snaking around the front of the motor and to the driver wheel well (like the factory line did)
I'm curious as to what the pressure reading is on the return line, is it ever even enough to read on the gauge?
 

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I'm curious as to what the pressure reading is on the return line, is it ever even enough to read on the gauge?
originally I had bought 2 of the same fuel pressure gauge..... not really thinking about it... but then yeah it was exactly what you're thinking - I had to swap out the return line gauge for a lower pressure fuel gauge.

its between 1-2 psi on average.


I originally installed them on both because I wanted to make sure my tank pressure wasn't the culprit of the loud injector noises. TLDR - it wasn't.
 

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You can use a brake line flaring tool to put a retention bead on hard line. I was able to use the original 3/8" fuel lines on my 1970 as the feed. I only had to trim a little near the fuel tank to fit the filter. I used 5/16" nickel/copper hardline for the return. You can find and easily modify plastic fuel line hangers from a newer junkyard car and run the 2 lines parallel. I was able to run the 5/16 return near the rocker pinch weld and through existing holes in the front drivers' torque box and a rubber plug just above the steering gear. The 5/16" line can go places that 3/8" can't. I was able to use the original fuel line clip attachment holes. The lines are securely attached and routed and almost look factory. It was not necessary to drill any holes in the car, except to mount the filter.

69s and 70s have 2 piece 3/8" fuel line that runs near the outside of the floor supports and near the rocker. I wonder if this line could work on earlier cars? It's generally away from the exhaust and other parts here. The factory line fits very nicely and would be hard for an amateur to duplicate. I used parts from Earl's. Watch the video below. It's pretty simple to hook up a hose.

https://www.holley.com/brands/earls/products/plumbing_an_fittings_and_hose/vapor_guard/
 

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Like schweigert, I ran two new Vapor Guard EFI hoses. I did elect to run 3/8" for both the feed and return. The feed is cut to insert the inline filter near the tank, but everything else is a clean run from the tank to the Sniper and the return line is the same. I installed new sub-frame connectors which enabled me to run up the passenger side and into the engine compartment like schweigert described. I did drill through the tunnel support (a solution I got from Kelly H. in a thread from a couple years back). The photos were taken prior to welding the sub-frame connectors in place.
 

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I would try to use as much hard line as possible, I just installed a Holley Sniper with external fuel pump, used hoses and I’m getting weird fuel pump noises, I think the hoses are ballooning and causing fuel pressure to oscillate.
 

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I would try to use as much hard line as possible, I just installed a Holley Sniper with external fuel pump, used hoses and I’m getting weird fuel pump noises, I think the hoses are ballooning and causing fuel pressure to oscillate.
what fuel pump and tank do you have? i dont have any oscillations - my fuel pressure gauge doesnt move from 60psi

I installed new sub-frame connectors which enabled me to run up the passenger side and into the engine compartment like schweigert described. I did drill through the tunnel support (a solution I got from Kelly H. in a thread from a couple years back).
wow thats well done - i wish i had that subframe connector to run along - it was a little tricky anchoring them in the trans tunnel with the axel still in there lol
 

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what fuel pump and tank do you have? i dont have any oscillations - my fuel pressure gauge doesnt move from 60psi

I do not remember what fuel pump, I believe it is a generic brand, I have a stock tank only installed a larger fuel pick up and am using stock hard line for return. Pump whines up and down, maybe the fuel hose is not rigid enough.
 

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I have the 20 gal on order. I know it's 2 gallons less than my original tank. With fold down seat there is no room in the trunk so I could use the 1" more room on the floor (it's not as tall). 20 gallons is enough.

Really like the lines are in the original location and not in the trunk. Ordered through Summit and just got an email est ship at the end of the month.

Right now the Stealth II might be the best deal. Also got $50 off Summit deal they just ran, $450 out the door Aeromotive seams to be all USA stuff. Just concerned how long the foam will hold up. I heard the people with Tank inc set up experience fuel starvation on turns and hard accel below 1/2 tank.

Although the Spectra tank has an attractive price that tray or baffle is even smaller and causes starvation sooner. Then figure in our members that used these tanks had black junk in the tanks and ruined fuel pumps.

Using Nickel-copper 3/8th hard line with AN fittings. Will have flex from firewall to TB with fuel pressure gauge in feed line.
 
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