Braided SS fuel lines

[Fire604]

Has anyone replaced rotted hard lines from the tank to the engine with braided ss lines? I know folks that hve fuel cells in place of the stock tank use them and I'm considering doing the same just with the stock tank.

Would I be able to cut the barbs off the lines from the tank and flare them for -an fittings?

Thanks for any replies. BTW, tried the search function w/o success.

[d240zx2]

My Z is rigged with solid SS lines from the tank to just aft of the firewall, then -AN fitted to SS braided lines to the fuel block and carbs. Seems easier that way and some less costly.

[Mike W]

I will warn everyone up front that this is likely to be a long post. When I decided to install braided fuel lines in my 260Z I did not find a lot of info on this on the forum, so I thought that I would write up my experience so that others wanting to do this could benefit from what my son and I have just completed.

I had been planning to change out the old rubber fuel lines in my engine compartment with braided SS for some time, and also did not find a lot of info on the site for this upgrade. I did contact Frank in Houston (D240zx2) who has done this and received some good guidance from him, but ended up having to make some design mods to make this work with my late model 260Z.

The primary reasons that I wanted to make this change was to:

1. replace the old worn rubber lines

2. re-configure my electric fuel pump so that it would run at any time that the car was in the "on" position

3. add a more precise and better mounted fuel pressure regulator

4. bring individual fuel lines to each of the triple Webers I have installed

5. improve the overall look of the fuel distribution system in my engine compartment

With the triple Webers on my car I have found that after prolonged periods of non use, the car was very diffcult to start. I believe that this was caused by a low / no fuel situation in the bowls of the Webers due to evaporation, and wanted to develop a solution that would allow me to pump fuel to the carbs without waiting for the mechanical pump, which seemed to take an excessive amount of time.

So I put a plan together for the installation of a new electric pump, new pressure regulator, fuel log, as well as the SS lines themselves.

At the start of this exercise both my son and I were complete novices when it came to AN plumbing and I found the multitude of different plumbing options to be very confusing. So I did quite a bit of research on this topic and found the following site to be very useful in terms of tutorials as well as a source for many of the products I needed to complete this exercise:

http://www.anplumbing.com/

I also found that actually putting my plan down on paper with all of the necessary components was extremely useful as you could easily see all of the different adapters, connectors, etc that were needed for the installation. I have attached a PDF of the document that represents the final install that we completed over the weekend so hopefully this will help anyone else that wants to try this.

There were 3 primary challenges to this project:

1. learning the ins and outs of AN plumbing

2. electrically connecting the new fuel pump by utilizing the existing wiring in the car

3. going from the OEM fuel hard lines in the engine compartment to an initial AN fitting

I already mentioned a few things about basic AN plumbing but one other key thing to note is that all of the fittings utilize a 37 degree flare as opposed to the more common 45 degrees which I believe is used on standard NPT fittings. In order to connect to the existing hardline, you will need to flare it to mate to the appropriate 37 degree connector. This requires that you have a 37 degree flaring tool. (Sorry if this is boring to those that may already know this).

Next the fuel pump.

So on my late 260Z, the OEM fuel pump was configured to only run when the car was in the "ON" position and the engine was running at a minimum of 600 RPM's. Unfortunately this configuration did not allow me to address one of the key issues I was trying to solve, which was the abilty to pump fuel to the carbs with the car in the ON position but not yet running. I used my FSM to unravel the rather complex factory wiring and was able to locate the power wire that was routed to the OEM pump from the relays installed above the fuse box on the passenger side of the car. I ended up tapping into this and powered it through an inertia switch which I located in the glove box, so I still maintained the safety of killing the pump in the event of an accident. Now the pump will run anytime the key is in the ON position. Challenge #2 solved.

The third challenge was actually the hardest and my son and I spent 3-4 hours getting an AN adapter on the stock OEM line. (I decided not to replace the hard lines all the way back to the tank as my lines were in pretty good shape). Unfortunately I was not 100% sure of the size of the OEM line, but I measured approx 5/16 inch with calipers. I didn't really know if this was a true 5/16 or some close metrric equivalent. I ended up using a "tube nut" and "tube sleeve" from Earls that supported a 5/16 inch hard line and it was a perfect fit. At that point we thought we were out of the woods, only to find that the hard line where we were going to connect had a slight bend in it and the sleeve would not slide over. We ended up having to cut the hard line further back (on top of the frame rail) where we had about 3-4 inches of straight pipe and could get sufficient room to install the nut and sleeve and have room to make the required 37 degree flare. This also proved a little challenging as the space was very tight and the flaring tool barely fit, but we managed to make it work after 3 or 4 tries. We did have to remove the clamp which held the fuel line as well as the 2 OEM return / evaporation lines to get enough room to make the flare but this was relatively straight forward.

After that was completed, it was pretty much smooth sailing. We ran adapters / lines up to the new fuel regulator which we mounted where the carbon canister had once been installed. This was a perfect spot for it and the holes were already there. My son fabricated a bracket for the fuel log which we mounted on the center mounting studs of the intake manifold. I was a little concerned about heat and vapor lock with this position, but so far no sign of that and I hevan't even installed the heat shield yet.

A few other noteworth items:

1. It was really hard to find a fuel regulator that supported the low pressure required by the Webers and had the AN fittings I was looking for. I finally located one on Summit Racing (P/N 220065)

2. The inertia switch I used was sourced from Advanced Auto and is made by Intermotor (P/N S9300). It was a little pricey at $80 or so, but I felt that this was worth it for the safety it provided.

3. I found a fuel pump that was nearly identical to the OEM one from Datsun and supported a pressure range that was consistent with the Weber requirements. It is made by Facet / Purolater (P/N FEP 60SV)

4. I needed an inexpensive flaring tool and found one also at Summit Racing under their own brand.

5. Finally, althouhg I am very happy with the results of this project, I will say that the AN pluming parts are very expensive. I believe that I spent somewhere in the neighborhood of $250 for all of the bit and pieces I needed as well as the SS hose itself. I would do it again, but just a warning for those who may not know.

I've attached a few before and after pictures so you can see for yourself. I also apologize for the state of the rest of my engine compartment. I am in the early stages of doing a complete refresh and still have a lot of work ahead, but I at least have the fuel system done.

If anyone needs any further info on this, please feel free to contact me. Hopes this helps out a few other forum members.

Mike.

Fuel Distribution Design - Final.pdf

[LeonV]

Great write-up! I plan to do this as funds allow on my early 260Z with triple Webers, and this should save me some time. Thanks!

[240ZGL]

In doing my system I found the lines to be 7mm. The 5/16 in some spots is just a tad too big, 8mm was too large also. I got hold of some braided 7mm and felt right. The Facet pump works great with triples, but I haven't found a need for a regulator. I run a single pump to the original fuel filter and then to the carbs. I'm working on a factory fuel rail copy at this time.

Edited September 12, 2011 by 240ZGL

[zKars]

Ok, now THAT'S a write-up. Thank you! Proceedure, part numbers AND full list of suppliers.

A check valve in the line before the pump would also have lengthened the time after last start before the line drains and it becomes hard to prime again. The electric pump clearly removes any need for this. Maybe a suggested addition to your plumbing documentation. Part number 253006 on anplumbing.com for the #6 size. A mere $86!

A check valve is a very generic and typically cheap thing. Anyone have a supplier for a small one with 1/4 NPT threads?

Edited September 13, 2011 by zKars

[rocketdog]

Great write up! I am planning to install triple Webers in my late 260. Currently running '72 round top SU's. Have a pile of threads from this and other websites on issues, problems and ideas....and lots of opinions. I will be doing the braided SS route but will probably install the Webers with regular rubber fuel lines first to make sure everything runs right.

Fuel pump: Many posts say they use the existing OEM electrical and mechanical pumps with no problems with fuel delivery but install a pressure regulator to keep the Webers happy in the 3 psi range. I would like to do that and eliminate the need for extra wiring and emergency shutoff switch with a hardwired new electric pump. Comments?

Fuel return line: Many posts say a fuel return line is a must to keep the fuel flowing and cool and pump from possibly cavitating. You set up does not have that shown and I notice that MSA's Weber package has only 2 T's and 1 L connectors on their carburetor pictures. A return line would mean a T connection on all three carburetors. Your comments?

Distrubutor: After disconnecting the vaccum advance to the dizzy, did you change anything else with it?

Vacuum tap: Apparently there is a place to tap into the front manifold for vacuum for the heater/AC controls. I know the back manifold has a tap for the brake booster.

I haven't contacted MSA yet regading their Weber package and the specs they have on the system for jetting, etc. There are LOTS of opinions thoroughout the sites on this.

My Z is a show car and the SS lines will be the ultimate bling.

[Mike W]

Rocketdog,

I don't think that you will have any issues with using your existing OEM fuel pumps as long as you add an appropriate regulator before the Webers. You can get fairly inexpensive regulators that will work with the existing rubber fuel lines for your initial setup if you decide to stick initially with the OEM fuel system. This will be a throwaway item however when you do go with SS as you will need a regulator with AN fittings.

I also run triple Webers but in my case found that if the car sat for any lengthy period of time (1-2 weeks), it was very hard to start. Figured out it was fuel related and that the fuel bowls were essentially evaporating and that the mechanical pump was not able to prime the carbs efficiently. That's why I installed an electric pump that I could control before start. Also if you have a late 260, this is the same car as mine (manufacture date of 11/74), its important to understand that the OEM electric pump does not operate until the engine is started and so it has no impact to initial fuel delivery in the OEM configuration.

On the return line, I ran my first set of Webers with the same setup as you see on MSA and did not use a return. Never had any real issue with hot fuel and the resulting hard start problem. Also I do believe that if you wanted to use a return with the MSA setup, you would replace the last L with another T and connect to a return on the other side of the T. I also believe that in this configuration, you install your pressure regulator in the return line.

My dizzy is likely different than what you have. I have a Mallory Unilite without vacuum advance. The mechanical advance mechanism has a curve that seems to fit my car well. However I did run with the OEM dizzy for years and all I can remember doing was advancing timing a few degrees, if that.

The vacuum taps will vary based on the mainfold that you get. The one that I have does have two taps, but I have the front one plugged off. In the rear tap I have an adapter installed that has lines for both the small AC/Heater controls as well as a large one for the booster.

Hope this helps you out. The Webers can be great but it does take some time to get them right. There is a lot of info here as well as other places that have great tips on tuning. It took me a while, but once you understand how they work and get a process in place to zero in on the best configuration for your car, it's not all that difficult.

Also, I just recently purchased a new set of Webers for the same car and got them from Pierce Manifolds. I have no affiliation with them at all, but will say that they were quite helpful and had great customer service.

I've attached a few updated pictures of my engine bay since I completed the SS fuel line upgrade that might help you out.

Hope this helps.

Mike.

[rocketdog]

Mike. W,

Thanks for the reply....and the pics. Lotsa SS braided under your hood! I'm also going to go with the screen/mesh air filters or socks on the air horns. Don't want to clutter up the look with big honker K&N's for the little I drive it. (I have Wieands, like Ramflo, on my SU's....checked this weekend and there is little foam filter left, apparently dried up (Arizona!) and got sucked in and cooked!)

Fuel regulator: I've seen other posts that say you put it on the return line like you said, but that makes no sense except that it would create a restriction to assure the required preseeure at the carbs. I believe I read where the current OEM return lines have a restrictor in them, so that is my thought process...but ther only reason I can come up with.

I've read about the fuel evaporation issue. My current SU's are intially hard start and that may be the issue. Once it has run you can restart with just a quick twist of the key.

I'll check out Pierce Manifolds. MSA $$ went up since last fall when I was first looking. Interestingly though I have the old MSA "blue" catalogue and their price then was $2K, so their current price is still 25% less than that.