Underbody Fuel Line Routing

[gary32]

I use 3/8" copper rubber isolated for both supply and return in the stock frame rail location meeting fuel line rubber with proper fuel line clamps. Fuel cell foam in the stock 1974 tank, E30 pump and sender in the tank 2nd pump on top feeding a surge tank because if your power adder allows you to accelerate hard enough she will starve.

[02TurboMI]

@Son of Marty @TobyB To be ultra specific, I'm planning on using Earl's UltraPro double-helix ribbed PTFE, braided stainless steel hose (https://www.holley.com/products/plumbing_an_fittings_and_hose/hose/ultrapro/ultrapro_stainless_steel_braided/parts/690006ERL).

 

I'm confident this can withstand daily driving in harsh environments without breaking down. Or no?

 

[TobyB]

I just used stainless steel tubing

https://www.summitracing.com/parts/sum-220208-25

and stainless tube nuts

https://www.summitracing.com/parts/ear-ss581806erl

 

with a stainless lube for assembly.  I brazed the ends on for the race car,

simply because I didn't have the tube nuts at the time.

 

I wouldn't spend THAT much to deal with fuel- it's not THAT

dangerous, compared to a lawyer with a loaded briefcase...

 

t

 

 

[AceAndrew]

.....An ok option for a race car or one and/or one where the hose will be systematically replaced at predetermined intervals.  Otherwise pipe is a much longer-lasting option.

 

This is a case where fancier doesn't mean better (given the application).

[Son of Marty]

OK I'll state I'm pretty much anti stainless hose on cars, IMHO the only place it can be justified on a 02 is the brake hoses other wise again IMHO using a hose with a 3000 psi bursting strength to handle a 30 psi fuel system just plane lacks any engineering  elegance, adds weight and a host of other problems for no good need. Tubing on the other hand is light weight and probably has a burst pressure above 6000 psi and needs almost no maintenance. But it your car and what you are proposing will almost surely work for a long while, so do what you want. 

Edited December 7, 2019 by Son of Marty

[TobyB]

Quote

 E30 pump and sender in the tank 2nd pump on top feeding a surge tank because if your power adder allows you to accelerate hard enough she will starve.

I learned the hard way that if you put the regulator in the trunk, and accelerate at a good clip, 

fuel has enough mass that you also run low.

Likewise, hard braking will overrun the floats in DCOEs.

 

stupid classical physics.

 

t

 

[02TurboMI]

2 hours ago, Son of Marty said:

OK I'll state I'm pretty much anti stainless hose on cars, IMHO the only place it can be justified on a 02 is the brake hoses other wise again IMHO using a hose with a 3000 psi bursting strength to handle a 30 psi fuel system just plane lacks any engineering...

I'll take that. It does seem overkill for a daily driver. But I like overkill too (Murphy's Law). My main concerns are sagging and deterioration before the end of the life of the car itself. I may just go hardline. What are some of the best quality that's easy to deal with hardline (brand) for fuel?

 

Edited December 7, 2019 by 02TurboMI

[NYNick]

This is what I used. Steve from Blunt suggested it. Aluminum fuel line tubing.

https://www.summitracing.com/parts/sum-g2516

 

Deleted the underbody fuel pump and went with one in the tank. I ran it all along the stock hard line locations, securing it as I went. I used high pressure rubber fuel injector line to mate it to the tank and the engine once it had arrived where it needed to be. Transitions from tube to hose were double clamped. Worked great, looks great, cheap as well.

 

I think I have more than half of the roll leftover. IIRC I needed 11 feet. (could be wrong, it's been a while)

 

As I said earlier, it was a challenge to pre-bend it before 'threading' it through the rear subframe and down the underside of the car, but it's easy to bend, kind of like cuneiform brake line. 

 

The PO (or a mechanic) had used rubber hose. That stuff went right in the trash.

Edited December 7, 2019 by NYNick

[jimk]

1 hour ago, NYNick said:

Transitions from tube to hose were double clamped.

With no barbs or bubble bumps in the tube to keep the hose from slipping off, a more secure choice for the high pressure supply is the flare nut with a tube sleeve from places like Earl's.  The backing piece takes the twisting action when tightening to protect the aluminum tube.

[rcf925]

I ran 5/16" aluminum from trunk all the way to within a few inches from connection on dcoe45, when I bought car someone had a rubber line all the way up next to crimp on rocker below door that was zipped tied, It was out of the way of everything so I just followed the same route plus aluminum is easy to bend without collapsing

[dlhoovler]

As I said earlier, it was a challenge to pre-bend it before 'threading' it through the rear subframe and down the underside of the car, but it's easy to bend, kind of like cuneiform brake line. 

Man, I'd be leery of using cuneiform line on my car. That stuff's gotta be ancient!

[emoji6]

-Dave

Posted from my phone.

[xr4tic]

I bought NiCopp nickle/copper tubing (~$40 for 25' of 3/8) and Swagelok AN tubing fittings - https://www.swagelok.com/en/catalog/Product/Detail?part=SS-600-6-6AN

 

Plan is to run short sections of Aeroquip socketless hose with AN fittings for the hookups.

 

I bought all the stuff, but no motivation to go out in the cold and install it.

[NYNick]

1 hour ago, dlhoovler said:

 

 

Man, I'd be leery of using cuneiform line on my car. That stuff's gotta be ancient!



-Dave

Posted from my phone.
 

 

Spelling Dave, spelling.?

[pato2002]

I will post some photos tonight but I ran CuNi tubing for supply and return along the factory route. To secure, I welded little weld-nuts to the floor and then screwed clips to them. It came out pretty good although I determined that tube bending is much more difficult than it looks.

Edited December 12, 2019 by pato2002
Added clip pic.

[gary32]

On 12/6/2019 at 8:35 PM, TobyB said:

I learned the hard way that if you put the regulator in the trunk, and accelerate at a good clip, 

fuel has enough mass that you also run low.

Likewise, hard braking will overrun the floats in DCOEs.

 

stupid classical physics.

 

t

 

Toby,

I last had dual 40 dcoe Webbers on my stage 2 M10 no pressure regulator, 20 years ago.

For the last 20 a sorted single turbo 13b rotary under hood produces some impressive thrust.

Apples and oranges, rice and strudel...