In-tank electric pump for behind the seat tank?

[Phill]

Has anyone done this? I'm thinking of getting out the TIG welder and making a stock behind the seat tank except a Walbro 255 and sump, but I thought I would check here for info?

I'm dropping a ramjet 350 in this winter, and feel like the intank pump will still be quieter even though its in the cab, then a external pump.

Any opinions are welcome, I want to keep the behind the seat tank for no other reaosn then I like it there, I like the filler cap on the side of the cab, and I like not having one on the bed/box.

[SS Tim]

At those kind of working pressures I would not want a flex line inside the cab with pressurized fuel. Plus a formed tank (by most people) is not going to be as neat as the stock stamped tank. If you feel you must use an intank pump go through the stock sender hole.

[67 chevelle]

sounds like a plan , great engine choice , the only drawback I can think of would be noise , might be loud , im sure someone has done it , you might ask on ls1tech also , as most are injected , good luck and do a build thread when you get started

[68 short step]

i have done this, you'll find that a fuel pump doesn't fit through the stock sending unit hole, its too wide... but with a little creativity, welder, and some fittings you can make it happen...

[FLDBRED]

That's a great looking truck, any other pictures?

[Madmartigan]

Custom Classic Trucks Magazine did a EFI conversion and kept the original tank behind the seat. I found the article on their website. EFI_Tank

[Phill]

[QUOTE=68 short step;6233861]i have done this, you'll find that a fuel pump doesn't fit through the stock sending unit hole, its too wide... but with a little creativity, welder, and some fittings you can make it happen...
QUOTE]

This is what I'm talking about! What did you use to seal your tank flange? I'm thinking of using the GPA series pump and mount from tanksinc and putting it beside the original pickup, then keeping the original for the fuel level sender.

How loud was this in the cab when said and done? The fuel and seat should muffle it better then a frame mounted external I'm thinking.

I will be sure to start a build thread, this winter this truck should get 100% new drive train, I'm taking it to Alaska and want it to run like a top.

[68 short step]

Originally Posted by FLDBRED

That's a great looking truck, any other pictures?

yes, look under my sig at project big red
[quote=Phill;6233886]

Originally Posted by 68 short step

i have done this, you'll find that a fuel pump doesn't fit through the stock sending unit hole, its too wide... but with a little creativity, welder, and some fittings you can make it happen...
QUOTE]

This is what I'm talking about! What did you use to seal your tank flange? I'm thinking of using the GPA series pump and mount from tanksinc and putting it beside the original pickup, then keeping the original for the fuel level sender. i moddfed the stock sending unit , then replaced the stok sending unit with a autometer one... ill see i can find some more pics

How loud was this in the cab when said and done? The fuel and seat should muffle it better then a frame mounted external I'm thinking. not 100% sure yet, but it is quite muffled with the seat, sound deading material, and carpet installed. i also used the cork gasket material to seal the flange area

I will be sure to start a build thread, this winter this truck should get 100% new drive train, I'm taking it to Alaska and want it to run like a top.

[68 short step]

[Katrina/10]

An 87-90 Chevrolet truck TBI pump fits in the tank with no mods.

[GCncsuHD]

Originally Posted by Katrina/10

An 87-90 Chevrolet truck TBI pump fits in the tank with no mods.

The TBI pump will not fulfill his fuel needs, the TBI pump will only generate 15-18psi or so, a MPFI system like the Ramjet he is installing needs 50-60psi to operate.

[MARKDTN]

Originally Posted by GCncsuHD

The TBI pump will not fulfill his fuel needs, the TBI pump will only generate 15-18psi or so, a MPFI system like the Ramjet he is installing needs 50-60psi to operate.

If a GM TBI pump fits then a TPI and an LT1 pump are the same size so they will fit too. '89 IROC for TPI and '96 Caprice for LT1

[Katrina/10]

Just saying a TBI pump fits, if a high pressure pump had the same dimensions, it would fit also.

[mtm_seven]

I can confirm that an external pump with a stock tank will not work properly. I tried that caca for months before I broke down and got a boyd's tank with an internal pump. High pressure pumps do not "suck" much if at all. so when the pump is trying to pull fuel down to the frame, it starves.

The aeromotive pump that came with the Boyd's tank gets loud when fuel level is low. I can imagine that it would get pretty annoying in the cab.

Once I removed my stock tank, I left the cap to give the illusion that the tank wasn't moved. (if your intent is to keep that part looking stock)

Just another idea. Albeit an expensive one.

[67_C-30]

My buddy has done several of these using TPI pumps. He was able to fit them through the stock hole.

[Phill]

Ok, I'm about to put a walbro 255 on the tanksinc PA mount into the stock tank, is there any comments on how loud a intank pump is in the in-cab tank??

I will most likely dyno-mat the tank, but I'm worried it will drone in the cab a little now.... hopefully the headers, 3" pipes, and 40 series flowmasters on the ramjet drown it out :P

[imjeff]

I still like the plan of soldering bungs in the bottom of the tank that are tee'd together to supply an external fuel pump, then using the original supply line as a return. Nice truck BTW!

[Daaaanz67]

Nice truck. If you can get this to work it will be awesome. Can I suggest you take a look at ls1nova build thread and check out the sump system he installed on the stock tank. Would help with fuel starvation if you could sink that pump in a sump. I try to keep my tank 1/4 full all the time with my ls conversion. My external walbro is mounted on driver side frame rail and can only hear it at initial start.

[Rod Run]

I would think the noise from the pump would drive me crazy. Lots of times you can still hear pumps when they are mounted at the back of a vehicle, when it is even outside the cabin.

[bMr]

If you want to keep the stock tank then search for the Edelbrock Universal EFI Sump Fuel Kit.

"This Universal Sump Fuel Kit is designed to provide the necessary high fuel pressure required for EFI applications in vehicles equipped with low pressure carbureted fuel systems. It's a complete self-contained system that can be installed under the hood of any vehicle easily. The unique design of this system allows it to deliver a constant fuel pressure of 49 psi or 60 psi, which is necessary to operate an EFI system and will not require a fuel return line. This kit is intended to be used with the existing factory fuel tank and low pressure pump. The kit includes the fuel Sump tank with high pressure pump and regulator pre-installed, wiring harness, mounting bracket, hose, fittings and all of the necessary hardware for installation."

It is designed exactly for these types of situations...which means it isn't cheap.

However, the stock fuel tank doesn't need to be relocated or modified in any way and there is no chance of cornering causing fuel starvation at lower fuel levels (as may be the case with an unbaffled tank and a high pressure electric pump).

[Phill]

well I whipped this together last night. If its too loud I will dynomat the tank, if its still too loud I will do something else. My buddy has external pumps and they drive me crazy. Even with my ear to the tank in my blazer with the same walbro 255 pump its quieter.... so we will see.

I was anal with the measurements but I have the sump exactly 1/4" off the floor of the lowest part of the tank. I didn't baffle anything, but if its quiet and I run into fuel starvation problems I will build a baffled tank. I managed to not have to weld anything on the tank so I used my old one. I have a brand new one should I want to weld baffles in. Considering how low I got the pump, and how tall and narrow these tanks are.... I suspect baffles aren't to critical... for non-racing.

BMR, if I had of seen that from day one I may have went with it.

[Phill]

more.

[svgould]

Originally Posted by Phill

more.

Where did you get the bulk head that has the 90 fittings and electrical connections? The zinc colored part? I have some idea's and need that exact part!

Thanks

[Phill]

Tanksinc.com its their universal "GPA" mount.

[BigCountryx]

Nice job Phil. I guess you used the GPA-4 and modified the Lines inside the tank.