Fuel Lines & Hoses

[hrosenthal]

I think I got thrown a bit of a curve ball with the fuel lines.
As I've mentioned on a separate post, my engine supplier provided an electric fuel pump and I was making the decision to use the supplied pump vs. an in tank pump.
I decided to go with the supplied pump since I already have it and don't need to bother with a return line if I use it.
So I think I've got everything figured out, except for one bothersome detail.
The pump I have (http://www.summitracing.com/parts/sum-g3136-1) is designed to be used with 5/8" fuel line hose, whereas the hose provided with the FFR kit is smaller than 5/8" (I don't have it handy to check the size right now).
I used the smaller hose to run from the tank to the filter, but will need the 5/8" to run from the filter to the pump and from the pump to the hard line.
I'm not sure if it's ok or not to mix hose sizes.
Should I go back and use the 5/8" hose across the board, or can I just leave what's already done as is?
thanks

[68GT500MAN]

I looked at your link and that pump has 3/8 inlet and outlet connections. Are you sure that you are needing 5/8" fuel line (That is huge)? I do not know what FFR is supplying in the kits now, back in the day it was 5/16" and an adapter was needed to get to 3/8". Remember, fuel line size is determined by Inside Diameter dimensions NOT the Outside Diameter. Can you post a photo so we know what you are trying to use?
Doug

[NukeMMC]

The connections for that pump are 3/8" NPT. 3/8" NPT (National Pipe Thread - Taper) is made for 3/8" pipe, which is .675" OD. You can get many types of fittings to adapt from 3/8" OD tubing (like what your fuel line will be) to 3/8" NPT. Most here will use a 3/8"NPT to 3/8" tubing flare or a -6 AN fitting. AN is measured by 16ths of an inch, so -6 is 6/16" or 3/8.

Tubing, piping and fitting sizes can be extremely confusing. Even pipe threads can be confusing with NPT, NPP, NPSH, BSPP yada yada yada.

Just remember that pipe is sized based on an OD that is a little bigger than the rated size (3/8" = .675"OD, 2"=2.375"OD, etc)
Tubing (steel or aluminum) is sized based on OD and wall thickness. Standard fuel line is 3/8" OD but you can get 3/8" tubing (non-structural) with a wall thickness anywhere from .010" on up to .120".

You asked the right question, which puts you way ahead of the game, instead of just trying to wing it.

[MVRight]

Yep, agree, good on asking the question. I did a bunch of research, reading both forums, and in the end when I finally got it figured out - I hope - :rolleyes: - I bought about a 1/3 of the connections over again. Best advice, draw it out, all the parts and fittings, and go over the plan again. Then be prepared by extra fittings! :)

[rich grsc]

I think I got thrown a bit of a curve ball with the fuel lines.
As I've mentioned on a separate post, my engine supplier provided an electric fuel pump and I was making the decision to use the supplied pump vs. an in tank pump.
I decided to go with the supplied pump since I already have it and don't need to bother with a return line if I use it.
So I think I've got everything figured out, except for one bothersome detail.
The pump I have (http://www.summitracing.com/parts/sum-g3136-1) is designed to be used with 5/8" fuel line hose, whereas the hose provided with the FFR kit is smaller than 5/8" (I don't have it handy to check the size right now).
I used the smaller hose to run from the tank to the filter, but will need the 5/8" to run from the filter to the pump and from the pump to the hard line.
I'm not sure if it's ok or not to mix hose sizes.
Should I go back and use the 5/8" hose across the board, or can I just leave what's already done as is?
thanks

Do not put the filter on the suction side of the pump, it goes on the pressure side of the pump!

[hrosenthal]

The connections for that pump are 3/8" NPT. 3/8" NPT (National Pipe Thread - Taper) is made for 3/8" pipe, which is .675" OD. You can get many types of fittings to adapt from 3/8" OD tubing (like what your fuel line will be) to 3/8" NPT. Most here will use a 3/8"NPT to 3/8" tubing flare or a -6 AN fitting. AN is measured by 16ths of an inch, so -6 is 6/16" or 3/8.


The inlet & outlet are 3/8 NPT, but the fitting that came with it are 5/8" barb. I spoke to Summit because I need a 90 degree fitting, and they sold me this fitting (http://www.summitracing.com/parts/GAR-J9002). I was told that was my only option. Perhaps I should check elsewhere.

[hrosenthal]

Do not put the filter on the suction side of the pump, it goes on the pressure side of the pump!
I was told to put a filter both before and after the pump.

[Bob Cowan]

The inlet & outlet are 3/8 NPT, but the fitting that came with it are 5/8" barb. I spoke to Summit because I need a 90 degree fitting, and they sold me this fitting (http://www.summitracing.com/parts/GAR-J9002). I was told that was my only option. Perhaps I should check elsewhere.

That's a heater hose fitting, not fuel. 5/8" = -10 AN. That's huge. That's NASCAR sized. Unless you're building a 900hp engine to run at 8,500 rpm's, that not the right size.

As said above, you fuel pump is designed to use 3/8", or -6. Which is just fine for anything less than about 600hp or so, NA. A power adder would require more volume, and a large size, like -8.


I was told to put a filter both before and after the pump.

You need a before and after filter for an external pump. The stock pump from ford has screen to weed out the big stuff. Place a 100micron filter before the pump, and a 10 micron filter after. The easiest way is to simply screw the filters into the ends of the pump, so it looks something like this:
http://i13.photobucket.com/albums/a256/bobcowan/smallFuelPump.jpg (http://s13.photobucket.com/user/bobcowan/media/smallFuelPump.jpg.html)

If there's any way you can run a return line, I think you should. It keeps the fuel cooler, and prevents vapor lock.

[avgjoe]

The "suction filter" is usually referred to as a sock and is more of a strainer or large particle filter With in-tank pumps it is mounted on the suction of the pump. Here are some: http://www.summitracing.com/search/part-type/fuel-strainers

[hrosenthal]

You need a before and after filter for an external pump. The stock pump from ford has screen to weed out the big stuff. Place a 100micron filter before the pump, and a 10 micron filter after. The easiest way is to simply screw the filters into the ends of the pump, so it looks something like this:
http://i13.photobucket.com/albums/a256/bobcowan/smallFuelPump.jpg (http://s13.photobucket.com/user/bobcowan/media/smallFuelPump.jpg.html)



Can you tell me what kind of filters these are?

[DaleG]

Can you tell me what kind of filters these are?

I may be wrong, but my brain tells me that the 10 micron be before the pump? What use is a 10 micron filter after the pump when the fuel has already gone through 100 microns? Also, harder to pull through 100 microns, than push. Please correct me if I'm wrong, and I'll have learned something.

[hrosenthal]

OK, I started over and bought some 3/8 NPT-3/8 Hose fittings, 3/8 hose, and clamps.
Going to order a 100 micron filter tomorrow.
We'll see how things go this weekend.

[Bob Cowan]

Can you tell me what kind of filters these are?

Those filters are no longer available, and neither are the elements. I switched to these filters:
http://www.summitracing.com/parts/sum-230116/overview/


I may be wrong, but my brain tells me that the 10 micron be before the pump? What use is a 10 micron filter after the pump when the fuel has already gone through 100 microns? Also, harder to pull through 100 microns, than push. Please correct me if I'm wrong, and I'll have learned something.

a 100 micron particle is 10 times larger than a 10 micron particle. You want to filter out the big junk before it hits your fuel pump. But electric pumps are not good at pulling fuel, so you don't want a filter that's too restrictive. After the pump you want to use a 10 micron filter, to keep tiny particles out of your injectors.

A stock factory car is set up the same way. On the end of the in-tank pump, there's a simple ylon sock. That's your pre-filter, for the big stuff. Somewhere after that, there's a much bigger filter for the tiny particles.