the pump that came in the kit
Summit SUM-G3136 - Summit® Electric Fuel Pumps
says in the instruction that it has to be gravity fuel fed so it doesnt damage the pump so it can prime properly..

now what i need to do? install a small hole on the bottom of the tank somewhere and lead it to the pump??
im friends with a good welder and metal worker so if thats the case its no problem..
but is this really true?? i was thinking of using the orignal EFI pickup in the tank and modify it so it will work with the pump
but if i need to drill the small hole to let the pump get fuel from underneat i will plug the hole of the efi pickup and leave the floater in there.. what do you think i should do here??

 

if you try to mount the pump under the gas tank the fuel should siphon to the pump don't be suprised if that pump leaks after a few miles those style pumps suck they are the same as the holley red blue and black pumps and i have a holley blue on my t-bird and i had to go through 4 pumps before i found one that doesn't leak

if i had to do it again i would have not gotten that style pump though maybe you can send it back and run the high pressure pump with a msd booster pump and a 3/8ths return line with a bypass fuel pressure regulator, but chances are you can't so i would get a cheap one on ebay that is the same style (i think you can pick one up for under $20) and carry that one with you so when the base plate gasket on your pump leaks you can swap that one in and your not stuck on the side of the road

 

ok.. its not that easy about sending back and stuff i dont live in the states

lets just pray it wont leak.. so making a small hole in the bottom is not a problem then?

 

I dont see the problem with either the tank pump or the return line. No matter what you do, (with very few exceptions being heavy mods to the engine) the basic lbs/hr of fuel to feed the engine without other changes will be the same. Fuel injection supplies enough fuel at the right ratio for your cubes at any rpm, so why would a carb use significantly less or more.

That means (to me ) the same flow rate and same return to tank as the FI. It does not follow that a carb at the same lbs/hr rate for a specific engine will require more or less return capability. I did the swap on an 85 anny bird w/302 (not HO) and a TB. I built a 306 (.030 over) with a comp 270 cam and used the same in tank pump and lines only I used a 3 port Mallory adjustable FPR. I ultimately went to a Holly projection (2bbl version) with the same fuel feed setup. I have yet to see an explanation why the same lines wont work.

Another .02's worth is why get away from FI? It is a fact that carbs are going (gone) the way of the dinosaur. Its not a swap that can be casually done without some PIA particularly if you dont know the electronics of your vehicle and what is involved to make the carb work. With about the same effort, you can study FI systems and understand what it takes to modify them. LOL anyway!!

 

about from FI to carb

the truck was a inline six with a MAJOR HEADACHE in the harnass

i swapped to a 5.0Ho and just tought carbs are easier

 

Now that I can understand . I can agree that there are cases where a carb swap is the simplest. If the 6 was FI with an in tank pump, it will have to be wired to make the pump run (pull up the Fuel pump relay). You should still be able to use a 3 port regulator (1 port from tank feed, 1 port, regulated, to the carb feed, and 1 port for overflow to the tank return). In that case, I wont argue about line sizes, maybe they are different. Just go carefully about ripping out all the old wiring----you might need some of it.

My bird had the OEM stuff, but the return was not 3/8. I think the Stang guys that do the swap are at a whole different level of mods. If the return needs to be 3/8's, then the feed must be sewer pipe size. It stands to reason, that the most return flow will be at Idle. Did you say what year the vehicle is?

 

thats why i bought the summit fuel delivery kit.. the harnass is broken... fuelpump doesnt work nomather what i do.. unles i putt direct 12v

so thats why im doing this mod... it came with the fuel line and everything...

its this kit..
Summit SUM-PUMPKIT8A - Summit® Complete Fuel System Kits

easy to do just i need to know if taping in the gas tank from underneat is ok ??????

 

Personally, I would never cut into a tank anywhere especially the bottom. I have not researched external fuel pumps, but there has to be a pump that has the capability to pull fuel just enough to leave the tank pickup at the top, OEM location. I am not sure if the OEM in-tank pump can be "pulled through" with an external pump. Even if you drop the tank and remove that pump and replace with a straight tube I would do that first. That would be less effort (my opinion) than trying to weld a pickup in the bottom of the tank, which would be a high risk of being scraped off.

In the past, I have seen plenty of pumps that mount to the frame, at the tank, but I dont recall if they are in conjuction with the in-tank pump. I would totally rule out any welding of extra pickup/return holes. (.02)

 

The Tank will be too thin to tap. Weld or bulk head fitting would be the only way, I wouldn't recommend either.
The existing pump from an EFI system should deliver more than enough psi to feed your 302. You should install a pressure regulator to reduce pressure or you will destroy the carb. I do not know the volume it will be pushing but I dont believe you will starve the engine.
As for controlling the pump you should be able to jumper it out to run for testing and then install a toggle switch for daily use. If you truck has a roll over fuel cut off switch I would reuse it.
When you turn the truck on you should hear the pump start to prime the system, it will shut off until it gets a signal from the ecu. If you install the adjustable pressure regulator there should not be an accumulation of fuel, it will return to the tank. This is not the best way and will result in the pump running when the switch is on but it will work.

Mallory 4309 - Mallory Fuel Pressure Regulators

I think thats the one I used on my Mustang.

 

My 85 bird w/302 had a slightly different in tank pump from the H.O. versions. The bird was not an H.O. so the rating was ~88 ltr/hr. I believe the H.O. engines were rated ~115 ltr/hr. Aftermarket pumps go considerably over that depending upon your use.

The Mallory 3 port regulator I used served the same function as the FPR on the fuel rail, except that I regulated the pressure down to ~7 psi. The rest was pumped back to the tank via the OEM return line thru 1 of the ports on the Mallory. I had a permanent mount pressure guage between the Mallory and the carb inlet that I could see from the front to watch the pressure and adjust.

I am not an expert, but I'll bet some on here are, so take this as my .02

Again, if your engine requires 50 lbs/hr (as an example) at max or whatever flow at any RPM, that is a function of cubes, cam etc and will not vastly change from FI to carb. So the flow from the tank and back via the return should not be greatly affected even though the pressures are greatly different between FI and carb. One difference is (my .02) that the carb has a fuel reservoir (bowls) and FI does not. FI depends upon instant fuel delivery to the rails without a reservoir.

 

ok guys thanks.. i guess i can make the stock pump work use stock fuel lines??

ithink i have to buy that regulator then becuase the one i got form summit doesnt have a return line..

Summit SUM-G3131-1 - Summit® Fuel Pressure Regulators

 

yes you can use the stock pump just get a bypass regulator, if you want to make a 3/8ths return line it's up to you, that's just what my friend told me who does carb swaps on mustangs all the time but like banshere said those mustangs are a lot more modified than most mustangs are, but they were using stock fuel supply lines so idk

here is the fitting you will need to get from your fuel filter to -6an Russell Performance 640850 - Russell Fuel Rail Fitting Adapters just snaps on there with a -6an male fitting on the other end

 

Ya know---after thinking about it a little, why dont you check into an old style external fuel pump (like the old Carter/holly/etc) that does not depend upon a return line. Reason being is that in order to get some of the necessary circuitry working you will have to 'fool" the processor into turning on the in tank pump (the processor has to detect that the engine is running from one of the distributor leeds--idt---I think) and also hook up the plumbing for the return line. You could then use a simple 2 port, regulator straight from a frame mounted electric pump (old style, no constant running). Then you could still keep the circuitry for the very important collision impact shutoff---provided you still have that somewhere in place. Somewhere, you can get a wiring schematic to hook that back up. I suspect even the later models have the same wiring and colors. That means you would disconnect the power to the in tank pump.

Another problem you might face is your engine (looking at your setup from your posts) is an HO engine and maybe has a bigger cam with heads and headers. The flow from that 6 cyl pump may not be adequate, so you will need a bigger pump anyway----dont want that sucker leaning out at rpm because of insufficient fuel.

Someone (a true expert) needs to tell us if the in tank pump can be "pulled through" or will it have to be replaced with a straight tube. I'm thinking that trying to hook a 3 port regulator with a return may be extra expense and kinda unnecessary---in addition to a bigger pump. The OEM feed line may be big enough----hopefully.

Anyway, thats some of my .02, see if any of it "fits"

 

you could do that... you would need a new timing cover that accepts a mechanical pump and an eccentric for the camshaft to go along with the timing cover and you would also need a mechanical pump, you could just make the intank pump into a pickup tube

 

1966tbird----naw, wasnt thinking of that----thats a possibility also, but might be too much work. I was talking about the old style electric pumps that feed directly from the battery (switched source) and bolt to a frame rail or somewhere up around the sheet metal around the axle area. They dont require a return line and will run/shutoff at a preset pressure depending on whether the floats are opening the needle valve for the bowl. They could be used in addition to the engine mounted std fuel pump, or used standalone. Dosnt require much plumbing and the power (12VDC) could be routed through the impact shutoff (that is a good safety feature in case of a wreck).

Big unknown (to me at least) is if the in tank pump can be unhooked and the fuel pulled through it by a pump further up the line. No need to go through the gymnastics of trying to make the in tank function and do it safely, since it is controlled by the PCM (powertrain control module-- AKA "brain/processor")