New replacement gas tank fuel line fitting q's

911 tweaks · 05-05-2014, 04:00 PM

I was wondering what you all are using for fittings on the bottom of a new replacement dansk gas tank in a long hood car...this car runs cis so it has fuel return to the tank...
My specific questions are:
1. there are 3 threaded holes in the bottom of the tank = 2 threaded holes @ size 22m x 1.5 thread pitch (tp) and these holes are up about 2" from the bottom of the tank...AND there is 1 smaller threaded fitting centered between these 22m threaded holes that is on the bottom of the tank at size 14m x 1.5 tp... what are you all using for fuel supply & what for return fuel to the tank...?

My thinking was to use 1 of the lg fittings for supply because porshe still offers a fitting to fit these lg holes and the fitting has a sock filter on the end that sticks into the tank...but I was thinking this fitting is high enough off the bottom of the tank that when the tank is down to ~1/8 full it will be unable to draw fuel to the engine... so then I was thinking to use the sm low center hole but should I be concerned about sucking the dregs out of the bottom of the tank with such a low bottom feed...? the car will be running a bosch type fuel filter after the fuel accumalator...AND i need to return fuel to the tank as cis systems do...

any and all help much appreciated with pics, p/n's and where to get your suggestion...I will post up a pic of the tanks 3 threaded holes, oe 22m fitting w/ sock on its end and the contraption I bought for use of the sm hole...
thx, bob

911 tweaks · 06:16 PM

ok here are the pictures... blue plugs are 22mm x 1.5 thread pitch...middle fitting is 22mm x 1.5 tp and has sock filter and 3/8" size fuel hose...right side is 14mm x 1.5 and I have both 3/8 and next smaller hose maybe 5/16" fittings i can thread into the 14mm adapter...but this won't work as it is too long = no room there for hose...

fittings how I may connect them up but I wish feed back on the fuel line fittings you all are using on your tanks, their size and where to get & does it matter which hole is supply & which is return to the tank...? there is nothing inside the tank so does it really matter or am I over thinking something else again...? :-)

"IF" I use the small center hole, I will definatly need a 90 or 120 degree bent fitting to clear the torsion bar tube...

Larger line coming off the body = on the right side of body as you look at the picture, is wanting supply = why it is larger diameter hose...tight confines here...

The old tank had lines coming off it at ~ 45 degree angle pointing twds lines on body but I have a brand new dansk tank & no one can advise where to get proper fittings & which holes to use for fuel supply & return...lLet me know what you suggest...thx, bob

CountD · 07:23 PM

Boy that sure is tight. Where you have everything looks right. On the Pelican brand new replacement tank there are two - one on the left for feed, and one on the right (threaded male). I had Len Cummings (BoxsterGT) make me a line for the return with a 'J' fitting to fit the return. Mine is a '75 CIS car, however, the new Pelican tank with the later fittings looks different from yours. I would ask Len because he has probably seen it, built it, and been there and done that. He is the expert, and knows what every line looks like.

CountD · 05-05-2014, 07:22 PM

Oh, and looking at your tank from the back:

1) The fitting on the left is in the right place - it's the main feed (hence the filter I would suspect, so that's right on).
2) The smaller middle I would suspect is the return (as the return is the smaller one next to the feed on an early Porsche CIS tank)
3) For sure where you have the Blue plug on the right is the plug on an early Porsche CIS tank. This is where it is on the '74 or '75 CIS tank.

So really, all you do is have to extend the rubber lines to fit in with the feed and return with clamps? You can buy the Porsche line here on Pelican brand new. You didn't plan on running those old rubber lines anyway...

CountD · 05-05-2014, 07:29 PM

Here is the bottom of a late '73 made tank for a '74 CIS car. You will see all the things I said in the above post.

So if you looked at it right-side up and straight on, it would be the large feed on the left, smaller return (the J tube) and the plug on the right. You have it right, just get the correct Porsche rubber line and make them longer and clamp it.

911 tweaks · 05-06-2014, 05:05 AM

thx CountD...so I am fairly close = I should or have to use the larger i/d hose for supply so enough fuel able to be supplied to the engine & the smaller for return as less should be coming back since the engine is using most of what gets pumped to the engine i presume...ok...this makes sense...
I was getting hung up on maybe using the small center hole as it sucks/is positioned the lowest on the tank, thus it sucks from the bottom of the tank which has good & bad aspects to it: good = can run tank lower on fuel level BUT at the cost of sucking all of the dregs out of the tank & it is a smaller hose which is probably not good for needed gas supply volume the engine should have...
ok, now to hunt for fillings...
I guess I will use the lg screen fitting for the supply and if i cannot find a 14mm with 5/16 hose barb that is short or offset to 120 degrees, maybe I will cut off the screen on another lg fitting & connect the return to it...
Anyone else have any ideas or where to get fittings...? maybe i should give len a call to see what he has...he DOES have & can do ANYTHING plumging wise on pcars...

Arctic Rat · 05-06-2014, 10:18 AM

Your tanks fitting/hole locations look more like the ones on my 1966 911. I don't know what a 75 should look like, but that set up is exactly like the original tank in a 66 carb car. JMO.
If CountD's picture is accurate for 75 as well the line fittings are built in to the tank and don't need the extra space of the inserts to make clearence.

Good luck
Joe D

911 tweaks · 05-06-2014, 10:49 AM

thx joe...i needed to get a new tank & it accomodate a full size spare tire...this is the only tank i could find avail these days...made by dansk & bought here from pelican...

I am going to use the 2 lg/22mm holes...1 for supply & 1 for return...the sm/14mm will be the drain for the tank as this new tank does not have the old style lg screw into the bottom of the tank screen set up...

thx everyone for all of your help here...on to the next project...steering wheel center shaft bearing replacement...oh boy...this will be fun...

BoxsterGT · 03:18 PM

This looks like a universal replacement tank for a 66-73 911 with provisions for all the variations; the early ones used a 14mm Banjo fitting that looks like this...........

the later ones with MFI used the sock filter with the 22mm fitting as you show in your photo if I remember correctly. Of course, you only need to use two of the three with one plugged just as you have it.

This should work just fine. If you have a need for any other Metric fittings or Copper seal rings I am happy to help.

Len