Lower fuel line questions (under tank) |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Lower fuel line questions (under tank) |
DC_neun_vierzehn |
Jun 9 2024, 07:48 AM
Post
#1
|
Member Group: Members Posts: 493 Joined: 16-November 20 From: Delaware Shore Member No.: 24,893 Region Association: MidAtlantic Region |
Looking for help regarding correct fuel lines while I await a new Dansk tank to replace the unusable one I received (thread here).
I have a '73 2.0. A PO moved the fuel pump up front and under the tank and cut out a door so that the fuel pump can be accessed from the frunk (like the '75 and '76). First question: regarding the send and return pipes on the bottom of the tank - the send line measures at 10 mm and the return at 8 mm, yet the list in the AA fuel line kit lists both lines as 7 mm. Is that correct? I didn't want to force it, but I cannot seem to get the 7 mm line in the kit over that 10 mm pipe. Here are pics of the pipes I'm speaking of as well as pics of what the lines were when I removed the old tank (a 5/16 AKA 7.9 mm USA made line on the send and a 7 x 3 made in Germany line on the return). |
DC_neun_vierzehn |
Jun 9 2024, 07:53 AM
Post
#2
|
Member Group: Members Posts: 493 Joined: 16-November 20 From: Delaware Shore Member No.: 24,893 Region Association: MidAtlantic Region |
|
bdstone914 |
Jun 9 2024, 09:45 AM
Post
#3
|
bdstone914 Group: Members Posts: 4,754 Joined: 8-November 03 From: Riverside CA Member No.: 1,319 |
Use rubber lines that fit your fittings.
7.5 and 9.5mm. They have to mate to the lines in the tunnel. |
DC_neun_vierzehn |
Jun 9 2024, 11:32 AM
Post
#4
|
Member Group: Members Posts: 493 Joined: 16-November 20 From: Delaware Shore Member No.: 24,893 Region Association: MidAtlantic Region |
Use rubber lines that fit your fittings. 7.5 and 9.5mm. They have to mate to the lines in the tunnel. Bruce, yes, the return line from the tank will mate with the line in the tunnel. Sounds like you're suggesting a 7.5 mm rubber line there (instead of the 7 x 3 rubber hose that was there originally). Ok. However, the send line does not mate with the tunnel line - it goes to the square fuel filter (8 mm inlet). Sorry I did not mention that in my original post. Thus, trying to figure out what line to use that goes from the 10mm tank pipe to the 8mm filter inlet. As stated in original post the original rubber line there was a 5/16" (7.9 mm). I guess was the PO's solution - it appears to have worked since it's in between the two sizes it mates to on each end. Should I just try to find a new 7.9 mm hose? For what it's worth ... the filter outlet goes to a 12 mm line which connects to the fuel pump. I'm using the square filter that came in Auto Atlanta's kit and a new fuel pump I bought from AA as well. The outlet from the fuel pump mates to the line in the tunnel. |
DC_neun_vierzehn |
Jun 9 2024, 11:35 AM
Post
#5
|
Member Group: Members Posts: 493 Joined: 16-November 20 From: Delaware Shore Member No.: 24,893 Region Association: MidAtlantic Region |
Were the pipes on the bottom of tanks various sizes depending up on the year?
Trying to figure out why Auto Atlanta's kit has 7mm lines for both pipes (when one pipe is 8mm and the other is 10mm). |
Chris914n6 |
Jun 9 2024, 11:47 AM
Post
#6
|
Jackstands are my life. Group: Members Posts: 3,437 Joined: 14-March 03 From: Las Vegas, NV Member No.: 431 Region Association: Southwest Region |
I've got a 75 with the front mount pump stock. Both tank nipples are 8mm. The pressure side goes to the filter then the pump, so the 3/8" hose fits in between. There is a filter hanger on the firewall (pedal side) across from the pump. In that pic you have the pump facing backwards from stock.
|
DC_neun_vierzehn |
Jun 9 2024, 12:12 PM
Post
#7
|
Member Group: Members Posts: 493 Joined: 16-November 20 From: Delaware Shore Member No.: 24,893 Region Association: MidAtlantic Region |
I've got a 75 with the front mount pump stock. Both tank nipples are 8mm. The pressure side goes to the filter then the pump, so the 3/8" hose fits in between. There is a filter hanger on the firewall (pedal side) across from the pump. In that pic you have the pump facing backwards from stock. Interesting. I sounds like the 75 and 76 had 8mm pipes on bottom of tank then. Hence why AA’s kit calls for a 7mm line on both. The old pump that I removed was positioned the way you mentioned but it seemed fit better this way (less stress on the wiring and lines). I assuming that as long as I have the right lines going into each end of the pump it should not matter). But if I’m overlooking something someone please let me know. |
Geezer914 |
Jun 9 2024, 03:10 PM
Post
#8
|
Geezer914 Group: Members Posts: 1,832 Joined: 18-March 09 From: Salem, NJ Member No.: 10,179 Region Association: North East States |
Are you running carbs of FI? For FI, Gates barricade 30R 7.9 mm., 50 psi, for ethenol fuel.
|
bkrantz |
Jun 9 2024, 07:43 PM
Post
#9
|
914 Guru Group: Members Posts: 8,221 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains |
Didn't some original fuel filters have 8 and 10 mm connections?
|
DC_neun_vierzehn |
Jun 9 2024, 08:31 PM
Post
#10
|
Member Group: Members Posts: 493 Joined: 16-November 20 From: Delaware Shore Member No.: 24,893 Region Association: MidAtlantic Region |
|
rjames |
Jun 10 2024, 11:11 AM
Post
#11
|
I'm made of metal Group: Members Posts: 4,199 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest |
Do early tanks have two different size lines coming off of the tank?
The send/return lines on my '75 tank are the same 8mm (OD). I would replace the 10mm fitting on your tank with an 8mm one. What Chris9146 said is how it should be set up. On my fuel filter there is an arrow indicating fuel flow direction. If yours doesn't have that, then it probably doesn't matter which way you connect it. I would also recommend Gates 3014 T2 fuel line. It's rated for ethanol and 225PSI, so safe for FI. Pricey, but better safe than sorry. I was able to buy it from my local NAPA store. |
DC_neun_vierzehn |
Jun 10 2024, 08:31 PM
Post
#12
|
Member Group: Members Posts: 493 Joined: 16-November 20 From: Delaware Shore Member No.: 24,893 Region Association: MidAtlantic Region |
Do early tanks have two different size lines coming off of the tank? The send/return lines on my '75 tank are the same 8mm (OD). I would replace the 10mm fitting on your tank with an 8mm one. What Chris9146 said is how it should be set up. On my fuel filter there is an arrow indicating fuel flow direction. If yours doesn't have that, then it probably doesn't matter which way you connect it. I would also recommend Gates 3014 T2 fuel line. It's rated for ethanol and 225PSI, so safe for FI. Pricey, but better safe than sorry. I was able to buy it from my local NAPA store. Why - what is the benefit of converting the original 10mm send pipe on my tank to an 8mm other than more hose options? Because I believe I already have that figured out - use a 9mm hose from the 10mm tank pipe to a Tangerine Racing reducer/adapter (9.5mm to 8mm) then a 7mm hose to the 8mm inlet on the filter. From what I can tell that should work. Hoses should be .5mm to 1mm smaller than the fitting. |
Chris914n6 |
Jun 11 2024, 12:39 PM
Post
#13
|
Jackstands are my life. Group: Members Posts: 3,437 Joined: 14-March 03 From: Las Vegas, NV Member No.: 431 Region Association: Southwest Region |
I used this on a 74 that got a front pump Gates 5/16, 3/8 Inch Hose Connector - 28594. $5 at Oreillys and usually in stock.
|
rjames |
Jun 11 2024, 12:44 PM
Post
#14
|
I'm made of metal Group: Members Posts: 4,199 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest |
Do early tanks have two different size lines coming off of the tank? The send/return lines on my '75 tank are the same 8mm (OD). I would replace the 10mm fitting on your tank with an 8mm one. What Chris9146 said is how it should be set up. On my fuel filter there is an arrow indicating fuel flow direction. If yours doesn't have that, then it probably doesn't matter which way you connect it. I would also recommend Gates 3014 T2 fuel line. It's rated for ethanol and 225PSI, so safe for FI. Pricey, but better safe than sorry. I was able to buy it from my local NAPA store. Why - what is the benefit of converting the original 10mm send pipe on my tank to an 8mm other than more hose options? Because I believe I already have that figured out - use a 9mm hose from the 10mm tank pipe to a Tangerine Racing reducer/adapter (9.5mm to 8mm) then a 7mm hose to the 8mm inlet on the filter. From what I can tell that should work. Hoses should be .5mm to 1mm smaller than the fitting. If you already have an adapter, then yes, no reason to change anything other than to reduce possible failure points. I was trying to address your question 'what line to use that goes from the 10mm tank pipe to the 8mm filter inlet'. You didn't mention you had an adapter until your last post. |
DC_neun_vierzehn |
Jun 18 2024, 07:23 AM
Post
#15
|
Member Group: Members Posts: 493 Joined: 16-November 20 From: Delaware Shore Member No.: 24,893 Region Association: MidAtlantic Region |
Do early tanks have two different size lines coming off of the tank? The send/return lines on my '75 tank are the same 8mm (OD). I would replace the 10mm fitting on your tank with an 8mm one. What Chris9146 said is how it should be set up. On my fuel filter there is an arrow indicating fuel flow direction. If yours doesn't have that, then it probably doesn't matter which way you connect it. I would also recommend Gates 3014 T2 fuel line. It's rated for ethanol and 225PSI, so safe for FI. Pricey, but better safe than sorry. I was able to buy it from my local NAPA store. @rjames thanks for the recommendations. But when I Google "Gates 3014 T2 fuel line" I don't get any matches. Can you share a link where I can buy this online? |
Superhawk996 |
Jun 18 2024, 08:37 AM
Post
#16
|
914 Guru Group: Members Posts: 6,713 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
Google SAE 30R14 T2 which is the spec the hose is made to.
Add Gates to the search if you want to see Gates products |
rjames |
Jun 18 2024, 09:00 AM
Post
#17
|
I'm made of metal Group: Members Posts: 4,199 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest |
|
Literati914 |
Jun 18 2024, 09:13 AM
Post
#18
|
Senior Member Group: Members Posts: 1,809 Joined: 16-November 06 From: Dallas, TX Member No.: 7,222 Region Association: Southwest Region |
.. (like the '75 and '76). First question: regarding the send and return pipes on the bottom of the tank - the send line measures at 10 mm and the return at 8 mm, yet the list in the AA fuel line kit lists both lines as 7 mm. .. This is because the 75-76 cars had both pipes as 8mm, and correspond with filter pn133.133.511 (8mm in, 12mm out). Assuming that's the filter you have - your best bet is to change the big pipe to an 8mm pipe (which maybe should have been included in the kit) .. (edited^^ after further considerations) |
914werke |
Jun 18 2024, 12:17 PM
Post
#19
|
"I got blisters on me fingers" Group: Members Posts: 11,085 Joined: 22-March 03 From: USofA Member No.: 453 Region Association: Pacific Northwest |
|
Lo-Fi Version | Time is now: 5th February 2025 - 06:53 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |