In-tank electric pump for behind the seat tank?

[Phill]

yep. just used 3/8" galvanized brake line and a flaring tool. it wasn't too hard to get it to sit where I want.

[BigCountryx]

Sounds like a plan. Thanks, I've been looking for a similar setup.

[Phill]

Got the tank Dynomatted and installed, when the key is turned and the pump rpimes you can here the hum, but as soon as I turn the engine over and fire it up you can't hear it. That's with the stereo off. It should be fine.

I'm sure when it gets low it my be louder, but that's just a reminder to gas up. :P

[67 chevelle]

Nice job glad it worked for you. Must be a lot quieter than an external how's it run

[Andy4639]

Do a gravity feed tank under the cab just big enough for the pump and return line to it. 1 gallon tank under the cab that is fed by gravity from the cab. Simple fix and you don't have to change the cab tank and shouldn't be to noisy either.
Baffling a electric fuel pump is a must if you want it to serve you for a long time. Just a little bit of air in it will cause problems down the road.

[RManson]

Very nice solution, but it could have been much simpler. Madmartigan posted what I did and it served me well for a couple thousand miles...

[Custom 68]

great solution. Neat idea and great execution. We sure have some creative folks on this board.

[Phill]

Originally Posted by Andy4639

Do a gravity feed tank under the cab just big enough for the pump and return line to it. 1 gallon tank under the cab that is fed by gravity from the cab. Simple fix and you don't have to change the cab tank and shouldn't be to noisy either.
Baffling a electric fuel pump is a must if you want it to serve you for a long time. Just a little bit of air in it will cause problems down the road.

HUH? I', sorry but I'll stick with the intank pump... it works perfectly.

[Phill]

Originally Posted by RManson

Very nice solution, but it could have been much simpler. Madmartigan posted what I did and it served me well for a couple thousand miles...

The point of this was to make it a factory styled reliable internal pump.... it wasn't about finding a easy or simple solution :P Externals are crazy loud and last.... well.... a few thousand miles, I won't run them anymore.

This is silent when running (and I mean 100% un-noticeable) and the pump is submerged in nice cold fuel (ie, long life like factory systems). If I wanted to run a external I would have Tig welded a 1/2" bung on the bottom of the tank, ran a line and never made this thread... lol

Yes baffles would be ideal, BUT, the tank is so tall and narrow I doubt you will run less then 2-3" vertical height of fuel in it ever. I have had zero issues with air yet and I don't go slow around corners.

This is a relatively simple solution for those who want to spend the time to have a reliable & quiet fuel supply system. If not, run a external...

[TwinsSpeedShop]

Originally Posted by Phill

The point of this was to make it a factory styled reliable internal pump.... it wasn't about finding a easy or simple solution :P Externals are crazy loud and last.... well.... a few thousand miles, I won't run them anymore.

This is silent when running (and I mean 100% un-noticeable) and the pump is submerged in nice cold fuel (ie, long life like factory systems). If I wanted to run a external I would have Tig welded a 1/2" bung on the bottom of the tank, ran a line and never made this thread... lol

Yes baffles would be ideal, BUT, the tank is so tall and narrow I doubt you will run less then 2-3" vertical height of fuel in it ever. I have had zero issues with air yet and I don't go slow around corners.

This is a relatively simple solution for those who want to spend the time to have a reliable & quiet fuel supply system. If not, run a external...

I like it! I've done a few using the stock tank but never like this. We always had issues with the fuel smell from the tank , any noticeable change in this for you?

nice job and great write up

[RManson]

Phill, don't get me wrong, you did a great job! That's definitely the best way to run an electric pump with the stock tank.
I agree with you on the external pumps, that's why my truck has an in-tank Aeromotive pump now, though the external Walbro never gave me any problems, I know better.
So many problems solved by putting the pump in the tank where things are nice and cool and the fuel can be used to muffle the sound.

[Daddy'O]

Cool! - suscribing for reference.

[Daddy'O]

Phill - Nice work!

Can you show me how you ran your return and vent lines and what you used for the lines? Plus - you have to show us your Ramjet.

This is the direction I think I'm going to go with my 'Greenie' project - also a Ramjet. I too want to keep the in cab stock tank and until I saw your thread I was going to settle for a tank under the bed system.

This site is incredible!

Thanks!

On edit - What did you do to block off the fuel line on the sending unit and did you do any other internal modifications to the sending unit?

[motorcritter]

I'm going with internal pumps on the C10- it'll run a 305 TPI, and I'm using saddle tanks. I can plumb OE style pumps and senders into them easily. I'm no fan of external high pressure pumps- noisy and relatively short-lived. OEM's use internal pumps- why should I question a few million dollars in R & D? If it works, don't fix it! Of course, I can break anything, so why create a potential problem?

[Phill]

I didn't get too fancy with the lines, I drilled another hole in the floor beside the factory one, and ran my return there through a grommet. I ran -6 an Aeroquip 350 psi line & socketless fittings for my high pressure line, and goodyear 3/8" 50 psi for my return. I ran a inline 10 micron filter and simply ran the lines ontop of my transfer case, and tranny to the ramjets feed and return ports (on the back of the intake beside the distributor). This way the lines never got close to the exhaust at all and they are out of sight. The filter can be replaced under the removable floor hump.

I used a breathable factory cap as the breather, but you could just as well seal it, and run a breather line from the bulk head out of the cab somewhere. I just plugged that port.

I've noticed no more fuel smell.

[Phill]

Oh, and to block off the original fuel line in the sending unit I simply cut it off below the part that supports the float for the guage sender and tig welded it shut. I cut the top off and JB welded it as I knew welding at the bulk head would have melted the solder used to hold it in. I'm sure JB weld would be fine on the bottom end as well.

[Daddy'O]

Excellent! Thanks so much for your response and photos as it helps me out a lot!

[67 chevelle]

the ramjet looks awesome in there , hows she run , you just got to love fuel injection

[Phill]

I was bored this weekend and tested the Low fuel level in the truck and ran her below empty, then a little offroad. NO cavitation, no fuel starvation. I am not worried about a sump or baffles at all now. I filled it up at the end and put in 20.8 US gallons.... I know... and she ran great right up to the gas station.

I'm impressed, right up to the end I was gassing it around corners and trying to get air in the pump. Looks like she's a runner.

[bMr]

The point about ours being a narrow tank and baffles being not as critical makes sense, especially if someone takes as much care as you did in getting the mount close to the bottom. This is great news. And your mount is sweet! Looks great.

[imjeff]

Thanks! I think that's exactly how I am going to do mine.

[Blazerowner]

This is a cool idea. I was considering putting my tank under the bed for an efi conversion but this makes sense as well. The only thing I am wondering is how much room you gain without the tank. I have my seat all the way back and still feel a little more room would be nice. Seem like moving the tank wouldn't make a difference though as the seat pretty much sits against the rear of the cab at the top of the set. Did you buy a new tank to do this?

[Matt Cramer]

Originally Posted by TwinsSpeedShop

I like it! I've done a few using the stock tank but never like this. We always had issues with the fuel smell from the tank , any noticeable change in this for you?

nice job and great write up

I'm using a fuel pump in the stock tank as well - stuck a Walbro 255 kit for a '94-'97 Miata on the end of the stock sending unit. Believe it or not, it bolted right up and slipped right on through the stock fuel tank opening! The fuel smell was the biggest challenge. I did two things to attack this:

1. Replace EVERY bit of the stock rubber on the fuel tank, including the gasket in the filler cap and the filler neck gasket.

2. Finding the right way to seal the wires into the fuel tank. (I had a separate ground wire as well - didn't want a marginal fuel tank ground to cause the pump to mess with my fuel tank readings!). I first tried running the wires through tight fitting grommets, and that failed. Tried JB-weld, and that didn't work. I finally put ring terminals on the wires and ran bolts through donut type grommets, and used RTV rated for gasoline use to seal the threads.

Without DynoMatting the fuel tank, that thing is LOUD. Glad to hear that some sound insulation may help.

Fuel starvation only seems to happen on hard corners when I'm well below 1/4 tank.

I simply used the vapor return line as a fuel return - seems to have no problem.

[brian1971]

Great write up planning on doing the same setup with mine,will be running a
Holley Stealth Ram EFI intake.Already have pump going to start work on tank next week.
Thanks Brian

[TwinsSpeedShop]

So it's been some time, how's this setup holding up? I've just picked up a very solid original truck and I'm going to do my usual LS swap and want to leave the factory tank.