EFI fuel pump, Stock tank.

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Will_Swe

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Hi!

I’ve put a 318 magnum in my Valiant -69. I will be running EFI with megasquirt. The engine only have mild upgrades like headers, keg mod etc. everything is connected, but need fuel too...

What’s the easiest way to get efi fuel pump? Will run with returnline..

alt 1.
walbro 255 lph pump into the stock tank from the top. With a homemade plate with pressure and return line from it. But it looks damn tight above the tank and trunk floor?

alt 2.
Bosch 044 inline pump.
Put in another line in sender unit for fuel supply to pump, and use original line as return. Or put a 12 mm pipe in bottom of tank to feed the pump?

it’s not gonna be a drag car, just fun daily driver. Will alternative 2 work well? Feels like easiest way to go?
Buying a EFI tank is not in my budget as I live in Sweden and that would increase the price with about 80% percent for me...

Or do you have any other ideas?
I will make my own fuel lines in 10 mm stainless tubing all the way.

thx in advance!! //Will from Sweden.
 
I ran an external Walbro pump with EFI. The big thing is keeping the restriction from the tank/ sock/ pickup/ tubing TO the pump very very low. If you use a suction filter make darn sure it is oversized, and RATED for suction side service, and has VERY low pressure drop. That is the key, I think.

Make certain your return is at least same size as supply. With my first TBI I made the mistake of using the 1/4" tank evap line for return. The drop in the return was on the border line. When I changed the system to Holley HP that got worse.
 
Hi!

I’ve put a 318 magnum in my Valiant -69. I will be running EFI with megasquirt. The engine only have mild upgrades like headers, keg mod etc. everything is connected, but need fuel too...

What’s the easiest way to get efi fuel pump? Will run with returnline..

alt 1.
walbro 255 lph pump into the stock tank from the top. With a homemade plate with pressure and return line from it. But it looks damn tight above the tank and trunk floor?

alt 2.
Bosch 044 inline pump.
Put in another line in sender unit for fuel supply to pump, and use original line as return. Or put a 12 mm pipe in bottom of tank to feed the pump?

it’s not gonna be a drag car, just fun daily driver. Will alternative 2 work well? Feels like easiest way to go?
Buying a EFI tank is not in my budget as I live in Sweden and that would increase the price with about 80% percent for me...

Or do you have any other ideas?
I will make my own fuel lines in 10 mm stainless tubing all the way.

thx in advance!! //Will from Sweden.

I used a surge tank set-up with a modified stock pick-up. Yes, it has a return from the surge tank to the main tank. It's very effective at supplying air free fuel even at very low fuel levels.

Sending unit mod 4.jpg


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I ran an external Walbro pump with EFI. The big thing is keeping the restriction from the tank/ sock/ pickup/ tubing TO the pump very very low. If you use a suction filter make darn sure it is oversized, and RATED for suction side service, and has VERY low pressure drop. That is the key, I think.

Make certain your return is at least same size as supply. With my first TBI I made the mistake of using the 1/4" tank evap line for return. The drop in the return was on the border line. When I changed the system to Holley HP that got worse.

sounds good! How did you connect it to the tank?
I have 5/16 tube on original pipe on sender? Ain’t that big enough for return?
 
I recently decided to go to a holley black pump with a return system and get rid of the Carter 6720 mechanical dead head. I purchased this sump:
https://www.ohiodieselparts.com/pro...-diesel-or-gasoline-fuel-tanks-black-anodized
It is good quality and will gravity feed an external pump. Pump is mounted in the pocket inboard of passenger rail forward of the bumper. I removed the 5/16" sender pickup tube and carefully drilled the hole for a 3/8" fuel line and soldered the new line in. I have 1/2" from the tank to 100 micron tube filter, to pump inlet. Pump outlet to 40 micron filter is 1/2".
They do make a sump with a feed and return port for a little more money.
 
sounds good! How did you connect it to the tank?
I have 5/16 tube on original pipe on sender? Ain’t that big enough for return?

For the power level you seem to be at I'd say yes, but you could run 3/8 hose to that and then the only restriction would be the short transition to and through the 5/16 return
 
For the power level you seem to be at I'd say yes, but you could run 3/8 hose to that and then the only restriction would be the short transition to and through the 5/16 return
If I choose this route, I might as well put in 2 x 10 mm pipe to use for pickup and return.
 
How do you think it would work without the surge tank?

Not too good, unless you kept the fuel in the tank above the half way point. Doing it this way might be ok, if you just wanted to get the car running etc.
 
I installed an in tank pump in my stock fuel tank on my fitech build. I was tempted to go with their Fuel Command Center system at the time, but didn't want more clutter in my car so I landed on the in tank.

I used a hole saw (after cleaning it thoroughly for safety reasons) to cut the top for the pump. I installed it on the passenger side due to the fuel filler and sender, which i am reusing.

After putting it back together i notice it sits a bit differently than it did due to the FP creating a gap between the tank nd floor. But it is not super noticeable.

After completing it i would recommend a proper EFI fuel tank if you want to go in tankwith the pump. Or run something external like mentioned above.
 
I installed an in tank pump in my stock fuel tank on my fitech build. I was tempted to go with their Fuel Command Center system at the time, but didn't want more clutter in my car so I landed on the in tank.

I used a hole saw (after cleaning it thoroughly for safety reasons) to cut the top for the pump. I installed it on the passenger side due to the fuel filler and sender, which i am reusing.

After putting it back together i notice it sits a bit differently than it did due to the FP creating a gap between the tank nd floor. But it is not super noticeable.

After completing it i would recommend a proper EFI fuel tank if you want to go in tankwith the pump. Or run something external like mentioned above.
Okey, I’m starting to lean towards in-line. Seems to be easiest way. Just worried about if it go dry when driving..
but did it work well apart from gas tank sittin lower?
 
Okey, I’m starting to lean towards in-line. Seems to be easiest way. Just worried about if it go dry when driving..
but did it work well apart from gas tank sittin lower?
Aside from that works great, the pump is nice and quiet and performs well so far. I would just be careful when putting it in place as you do not want to ground the pumps electrical terminals on the body. (If the terminals are on the top of the pump)
 
image.jpg
If your magnum is making similar power to a stock magnum the cheapest alternative is to use a stock dodge truck pump from an obd2 system. You’ll need obd2 fuel rails also. The stock pump has a regulator built in to it so no return line needed. You can either buy a new stock tank or use your original one. If you use the original, take it out and fill it with water. Cut a big hole in the top, weld on a few studs, drop in the sending unit and away you go.
 
SOMEPLACE I saw someone added an in-tank pump by modifying the stock sender. That pump assemble above does come apart, you might be able to do that without cutting the tank External regulator
 
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