Mounting Walbro FP Externally?

[oldskool-nick]

This is more of a hypothetical question as I don't plan on doing this, but I am curious...

Could a Walbro (255lph) fuel pump be mounted externally? It seems that it would be as easy as attaching a fuel line to where the pickup attaches, and then attaching the pickup to the other end of the line inside the tank. I know it wouldn't necessarily be beneficial, but is it possible?

I came up with this when I thought about going with dual Walbros. I could mount them side by side in the hatch right above that fuel tank access panel. Also, as far as mounting external FPs in the hatch, is that against NHRA requirements? Thanks

 

[cjsupra90]

well yeah, you could if you figured out something for the pick up, but the pump probably wont last long cause it is designed to be in fuel as much as possible to keep it cool.

 

[tubbie]

If you want external, just buy an external pump....

 

[cjsupra90]

If you want external, just buy an external pump....

agreed totally, plus you can buy an external that will flow more the two Walbro's.

 

[shaeff]

i believe the walbro uses the gas around it to help cool it down during operation. i dont think it would be wise to try to run one, or two externally. besides that, i think i read somewhere that the wally is a 'pushing' pump, and that it cannot suck gas in very well at any given distance greater than what it's designed for.

-shaeff

 

[siman]

I am tossing that idea to go external actually right now....I can pop by a junkyard....yank a gas tank and go!

I will update on my decision later..

_jonathan

 

[suprabad]

Wouldn't external be better all the way around...easier access, no having to pull the tank etc. Now I'm kinda sorry I went with an internal. I know that some of the external fuel pumps can be noisy but I understand they 're are quiet external pumps on the market also. So why internal?

 

[oldskool-nick]

If you want external, just buy an external pump....

Well, obviously, but I happen to have one sitting here that I'm going to be installing soon. Once again, I was just curious about whether or not it is possible. I never knew that the gas cooled the pump. Now I know

Thanks for the responses

 

[mkiiSupraMan18]

my 82 is external and it's been going for 3 years or so now. Is an external really too noisey to hear over road noise and the exhaust? I'd say just for the fact that you don't have to drop the fuel tank to replace it is reason enough to do it... Hell, let's go mechanical and put them on the block :icon_razz

if/when I replace mine, I'm gonna try an external pump....

 

[bluemax]

The problem with external fuel pump is that you really need to mount it below the top of the fuel tank. Fuel pumps are good at pressure but poor in suction. Thats why they are mounted inside the fuel tank. External pumps must be mounted very low, and might have problems priming. So sometimes there is an internal priming fuel pump used with an external fuel pump.
I called Aeromotive about their external 1000 HP fuel pumps and they say you need to mount it lower than the tank. But they have no data on how much performance they loose as the pump is raised or how high is too high. So I didn't go with them.

 

[suprabad]

The problem with external fuel pump is that you really need to mount it below the top of the fuel tank.

:3d_frown:


Why is that a problem? It sounds easy enough. I've owned lots of american cars (mustangs, camaros, a grand national) and I ran external electric pumps on all of them. As far as the noise goes as I stated earlier you can get quiet external pumps if you search around and they can also be insulated which deadens the noise.

 

[Clifton]

Walbro makes an external 255 lph pump. They are a little more than internal ones. I run one on one of my Z's.

 

[bluemax]

Electric fuel pumps are very good at pushing fuel (pressure) past the pump. But pulling the fuel in (suction) is a problem. The diaphram fuel pumps (mechanical) are better at suction but poor at creating enough pressure for fuel injection.
You'll probably notice a lot of cars in the '80s when everyone went to fuel injection and needed an electric fuel pump had two pumps. One in the tank for priming, and an external pump for pressure. Now days the manuacturers reduce cost be just putting one pump in the tank.