Fuel lines through the tunnel

[Harpo]

Has anyone used stainless steel fuel lines through their tunnel? I just purchased a roll of 3/8 stainless steel so I can experiment with it.

David

[dtxscott]

I think it's a reasonable mod since they are a PITA to change. The challenge will be getting connectors to adapt 3/8" pipe to metric threaded connectors.

I looked at doing this when I re-did my lines but ultimately went back with stock lines. Getting the connectors, adapters, etc. to work cleanly in the front of the car became too much of a headache for me. I was worried about persistent leaks on any compression-type connectors.

Flaring the tube-ends is another option.

[Harpo]

Yes, I'm going to add the 37 degree flair to one and and hopefully weld a male AN-6 bung to the other end.

David

[Harpo]

Looks like Tom has already done this

https://www.youtube.com/watch?v=5knrIAQa_a0
https://www.youtube.com/watch?v=LLL9VnPQ-PQ

[dtxscott]

Originally Posted by Harpo

Looks like Tom has already done this

https://www.youtube.com/watch?v=5knrIAQa_a0
https://www.youtube.com/watch?v=LLL9VnPQ-PQ

Great links. Thanks

[Solamar]

I'd be concerned with the SS tubes bouncing/rattling around in the tunnel (noise and wear) and possibly interfering with the throttle. The factory fuel tunnel lines (and most replacement sets) are contained in a smaller tunnel INSIDE the tunnel that isolates and protects your fuel lines.

I don't think it's possible to get rigid SS lines into the smaller tunnel in the tunnel.

[tperazzo]

I ran my stainless lines inside the tunnel in the tunnel and they don't rattle. There are some strategic spots to cover with tubing to avoid chafing.

Stainless is much harder than the stock nylon lines in my 74 and the nylon didn't show any wear.

You do need to choose your fittings wisely because that is what determines what fits through the tunnel.

[Harpo]

Tom, I was hoping to silver solder a male bung on one one and flair the other end after installation using the tool below. I suspect that The Eastwood tool would not be capable of performing the flair in car and I'm hoping the hydraulic tool can be done in car. I was also considering using heat shrink tubing on the outside to dampen any metal on metal contact.

https://www.amazon.com/gp/product/B01N9UVVSX/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=hotrodhippie-20&creative=9325&linkCode=as2&creativeASIN=B01N9UVVSX&linkId=c64f3dc3f581fc347a0c0e1ed392525e#customerRe views

[tperazzo]

Harpo, worth a try.

3/8" stainless is hard to flare so do a test piece for sure. Aluminum is an option too.

I pre-flared both sides. The front was an inverted flare because the fitting is compact. I did have to stretch the extruded hole a tiny bit on the front bulkhead.

I also pressure tested my lines flares before installing in the car. Something to think about.

My line return is 5/16"

[Harpo]

Thanks Tom,

I will definitely pressure test. Using the hydraulic 37 degree flair tool was a piece of cake on the SS (aluminum makes me anxious). Silver solder is out of the question as the -an6 male bung cross section is too small. Also I plan on using 3/8 line for both the supply and return.

[panzerfaust]

Originally Posted by Harpo

Has anyone used stainless steel fuel lines through their tunnel? I just purchased a roll of 3/8 stainless steel so I can experiment with it.

David

yes, a buddy did on his 930... he is in Bloomfield mi

best have the motor out in order to get them in there

[GH85Carrera]

I understand the desire to have steel lines. I just bet it will require the engine and transmission to be removed to have the access to install them.

I installed Len's plastic lines like the factory used. With two people doing a push-me-pull-you they went in easily. Doing them by myself was just an exercise in frustration. I am very happy they are in and done.

Good luck with stainless steel lines. I just suspect it is going to be way harder than factory style lines. I hope for your sake I am wrong.

[Harpo]

Finally got my tubing straightener. BTW this model is not strong enough to completely straighten my 3/8 SS lines. I believe the length is 64 inches.

[Reiver]

The flex poly tubing Porsche uses/used is basically indestructible..my Indy shop has never seen one fail and he's been in business 40 years. I'd trust that over rigid tubing any day in that tunnel.

[Harpo]

[Harpo]

[BoxsterGT]

Looks good Harpo-

Here is another w SS Lines done by a fellow Pelican...





I sent him custom M14 Male fittings that worked out well. No rattles or issues over a few years now.

Len

[911pcars]

I used this coupler to re-route a former feed line into a needed tank return line, then sourced a new flex hose from Len (BoxsterGT) for a pressure line.



Sherwood