Good location for mounting electric fuel pump?

[377]

I just put a 351w with an explorer serpentine set up in my rig and need to mount my electric fuel pump somewhere on it. My rig has a carbed motor with a factory rear tank. The pump I got is a Carter 4070. Is there a certain place that might be better then another to mount the pump? Anyone that might have pics of how they installed theirs woul be cool too. Thanks in advance for help.

377

 

[BRONCROB]

I mounted mine in front of the tank on the crossmember.No problems so far.I would keep it low where ever you put it,they push better than they pull.

 

[2E]

Yep, same here. Right above the rear axle on the xmember, close to the tank.

 

[Broncobowsher]

I have had that same pump in carbed applications, in AZ, run in Phoenix, in the summer. I have had it mounted behind the driver's headlight, by the master cylinder, and under the floor by the driver's seat. They all worked. I kept moving it due to installing other stuff that was a better fit for the space.

 

[70_Steve]

Almost the same place as the others. I have a BC Bronco's tank that has all the connections on the drivers side. When I was carbed I mounted the filter and Carter 4070 pump on the inside of the drivers frame rail, just above the rear axle.

 

[JWMcCrary]

Has worked very well and it's away from the heat

 

[xcntrk]

Just to add to the OP's question; those of you running the stock('ish) tank how are you plumbing a return line back to the tank?

 

[bronco t]

Do you need a return line for a carbureted motor?

 

[GrillMaster]

Do you need a return line for a carbureted motor?

no you do not

 

[bronco t]

no you do not

Do ya need a regulator?

 

[JWMcCrary]

Do ya need a regulator?

Depends on the pump, you do not with the 4070

 

[ntsqd]

If you want to run today's fuel without risk of vapor lock you need to run a return line and a by-pass type regulator. It complicates things I know, but today's fuel is made to run in EFI systems where it is under always pressure. It doesn't take a carb system into account. Because of that it vapor locks much more easily than the fuel available when the truck was built. I'm slowly converting my vehicles to this configuration. the EB is next.

 

[hawkgt]

Here is my carter 4070 install with stock tank and BC new hard lines. The big filter seems unnecessary but it came with the kit so I added it in.

 

[broncnaz]

Id venture to say that most of us are running todays fuel with no return line and have no issue. Vapor lock really doesnt have a lot to do with the fuel itself. It has to do with overheating said fuel. Yes a return line can reduce the possibility.
Todays fuel is not made for EFI. Its made because certain additives were deemed hazardous so they changed the mix in a few years when they deem these additives hazardous they will add a new set. EFI or carb has nothing to due with how the fuel is made.
Also there are EFI systems that dont have return lines. So your thinking is not universal in the EFI world.
In all actualility I think the old fuel mixture was actually more prone to vapor locking than todays fuel as in the summer fuel is made to reduce vapors. Winter fuel is a little more violate due to additives.
I dont think the oil companys and the car companies dont really work that closely together on what fuel blend to make next.
For the OP here's where my 4070 has been mounted for over 30 years. On the frame just forward of the axle. but as was said mount in a area where it wont see to much heat.

 

[Bronc937]

I have the same setup as you 377. This is my carter with braided lines and electric switch for the aux tank. Works great so far.

 

[377]

Guys,
I really appreciate all your help and pics. It confirmed my thought to keep it near the fuel tank. 70_Steve thanks for you and Motoman's posts on rebuilding the Dana 20 it really helped my recent rebuild of my transfer case. Thanks again guys.

377

 

[ntsqd]

Id venture to say that most of us are running todays fuel with no return line and have no issue. Vapor lock really doesnt have a lot to do with the fuel itself. It has to do with overheating said fuel. Yes a return line can reduce the possibility.
Todays fuel is not made for EFI. Its made because certain additives were deemed hazardous so they changed the mix in a few years when they deem these additives hazardous they will add a new set. EFI or carb has nothing to due with how the fuel is made.
Also there are EFI systems that dont have return lines. So your thinking is not universal in the EFI world.
In all actualility I think the old fuel mixture was actually more prone to vapor locking than todays fuel as in the summer fuel is made to reduce vapors. Winter fuel is a little more violate due to additives.
I dont think the oil companys and the car companies dont really work that closely together on what fuel blend to make next.
For the OP here's where my 4070 has been mounted for over 30 years. On the frame just forward of the axle. but as was said mount in a area where it wont see to much heat.

I'd say you totally missed my point. Today's fuel is formulated without regard to carb systems because there are so few of them around. Phrase it anyway you want, I call that intended for EFI. By not having to consider carb supply systems the low boiling point of the boiling point range of fuel isn't as much of a concern because EFI systems are pressurized. Even the so-called "returnless systems" (quotes because the 'return' is there - it's just inside the fuel tank) have the supply line under considerably more pressure than a carb system. With a mech. pump the bulk of the system is under a slight vacuum. If you do the research you'll find that even a one psi drop from ambient in the pressure on fuel reduces the boiling point by a very large amount.

For nearly the last year my DD has by a carb'd car and I drove a carb'd 302 for most of the 90's. I'm not buying that today's fuel is less vapor-lock prone than older fuel.

 

[broncnaz]

You dont have to buy the fact that todays fuel is less vapor prone just do some research. Todays Winter fuel blend is more vapor prone than summer blend. Thats easy to find. Not saying you dont have a point but gas is not formulated for EFI. Its formulated to meet EPA standards. A large part of that is less vapor. EFI is calibrated to run on todays fuels.
A return inside the fuel pump is not a return. Thats a relief. Unless your fuel pump is not inside your gas tank and theres a return line. A return system routes fuel through the whole system thus the fuel is in a sense cooling the system although it can start to heat up and all the fuel becomes warm.
EFI is a totally different animal when it comes to vapor lock as the higher pressure does help push the fuel past that vapor point. Plus unlike a carb there is really no place for the vapor to go in a carb that vapor can overpower the needle seat or just overpower the fuel pump itself. And like you sad fuel pressure does help the fuel take on more heat before becoming vapor but the gasolines vapor point is what determines when it starts to vaporize. Many of the additives used today raise the temp required to vaporize the gas.
I remember back in the 70's vapor lock seemd to be pretty common. Of course today there are not as many carbed vehicles but even so the ones that are running around dont seem to have the issues that were prevailent back then. Can we say "Ethanol" for one.

 

[ntsqd]

The couple of 'returnless' pump assemblies that I've looked at were not a relief internal to the pump. They were a port in the fuel pressure regulator that was part of the whole pump/sender/FPR assembly, but distinctly separate from the pump section. I'm calling that a 'return' as it is not an integral part of the actual pump itself. One such assembly truly was returnless, there was no FPR or anything like one. It would appear that the computer controlled fuel pressure via a PWM scheme or something like it.

My current DD suffers from hot shut-down percolation far more than my old 302 DD. The current car's lay-out, which includes a by-pass regulator and return system, should be less prone to vapor lock, and it is. However due to it's lay-out it should also not suffer from hot shut-down percolation as much and it is as bad or worse about that than the old car was.

The EPA specs can claim anything that they want, I'm relating my real world experiences with daily driving a carb spanning a considerable number of years. Part of the problem could be KA fuel, who knows? I do know that ARCO fuel is the worst for percolation and run-on. I don't buy it for carb'd cars.

Pressure vs. vacuum as related to boiling point is a curious thing. From my looking into it a slight depression in pressure does a whole lot more to lower the boiling point than a slight increase does to raise the boiling point. It does not appear to be a linear relationship.

Getting back to the OP's question, the less distance there is from the tank to an electric pump the better. This is the section of fuel line most likely to have vapor lock due to it being under a slight vacuum. Keeping it as short as possible is a good thing. Making it as large as possible to reduce restriction is also a good thing. And definitely use vacuum rated hose there. Emissions barrier hose may be a good call there as it's liner is fairly stiff and may not collapse under vacuum. Won't be cheap though you may never have to replace it. I've been testing it for almost a year on Pusk-Lok/Barb-tite type "socketless" hose ends. No leaks, no failures at TBI fuel pressures and under vacuum.
There's something to be said for the pump being below as much of the fuel in the tank as is reasonable. I'm not sure which is more important, that, or keeping the suction line as short as possible. They're both important and they're usually mutually opposing goals.

 

[broncnaz]

The couple of 'returnless' pump assemblies that I've looked at were not a relief internal to the pump. They were a port in the fuel pressure regulator that was part of the whole pump/sender/FPR assembly, but distinctly separate from the pump section. I'm calling that a 'return' as it is not an integral part of the actual pump itself. One such assembly truly was returnless, there was no FPR or anything like one. It would appear that the computer controlled fuel pressure via a PWM scheme or something like it.

Well either way the returnless system is still returnless no lines running fuel through to the engine then back to the tank. Probably more of a matter of schemantics but a relief is a relief If the FPR vents fuel back to the tank its a relief. As all its really doing is holding to a certain PSI then relieving the rest. The other pump just turns on and off as pressure dictates its not relieving or returning anything.

The EPA specs can claim anything that they want, I'm relating my real world experiences with daily driving a carb spanning a considerable number of years. Part of the problem could be KA fuel, who knows? I do know that ARCO fuel is the worst for percolation and run-on. I don't buy it for carb'd cars.

Yes the EPA can and does say whatever they want. They are the ruling authority on wether a gas formula meets there standards or not. If it doesnt meet the standard then its not to be sold. Its there standard that fuel should be less vapor prone. Although winter blends get a pass. The oil companies make up there own formulation and it either passes the EPA or it doesnt and they have to reformulate.


There are vehicles that just always seem to have vapor lock issues for some reason doesnt really mean its all fuel related just means theres something about the system or vehicle that its just prone to do it.