Questions for under bed gas tank guys....

[SCOTI]

Those of you that moved the tank under the bed, can I get some follow-up info on the job?
What kind of tank did you use?
How did you route the fill line?
What size fill line?
Any problems w/modern pumps 'shutting off' during the fuel fill process?

I removed the in cab tank for a blazer unit under the floor. I've routed the OE 2.25" neck to 2" line to the tank w/one 90° bend (2" 90° pipe) to the tank inlet (enlarged to 2"). The fill line which is approx 22" currently only has < 5° of slope so I'm concerned the gas from these 'environmentally friendly' gas pumps is going to constantly shut the freakin pump off which is something I hate dealing w/on my 74.

I did some Googling on the subject last night & didn't like all the issues I came across. Not just old cars (very common issue after searching through the HAMB) but new cars as well (late model Mustangs & Vettes seem to have more than their share of PO'd owners).

I really don't want to have this 'filling up' hassle w/a truck that gets driven daily. Your info could help me or possibly others make better choices when taking on this modification.... Thanks in advance!

[71meangreenc10]

I used the blazer tank (poly tank) and had a exhaust pipe bent to go to the tank. ( I will get pics) I added the vent at the top of the filler pipe and also have the vent line going to the charcoal canister that has a vent on it to from the tank. I still have problems filling up. I am thinking that going to a metal tank may resolve this issue. My filler is in the wheel well so it gets plenty of motion to get to the tank. I am thinking that the poly tank is causing the back pressure.

I have an extra fill tube so I will measure it.


Its super duper cold out in the garage, but I will go get some pics.


Thoughts????

Smitty

[jay6891]

I have the same problem. Had a pipe bent for the fuel line to see if I could help it out. I have a poly blazer tank. I believe that the problem is the actual fitting on the tank. What is it 1 1/2 id? I have two vents on mine and its still forever and a day to refuel. Thinking of cutting off fill fitting and welding a larger pipe into tank. I used to be able to do this when I worked in oilfield, but now, well lets just say I havent done it. Sorry no help, but I do feel your fustration.

[hvychvydriver]

was it hard to change your tank out and about how much did it cost for your materials

[Hart_Rod]

I'm using 1 1/2" fill neck into my tank and have not had any issues. I do have more angle than you though...

R/

[SCOTI]

Originally Posted by jay6891

I have the same problem. Had a pipe bent for the fuel line to see if I could help it out. I have a poly blazer tank. I believe that the problem is the actual fitting on the tank. What is it 1 1/2 id? I have two vents on mine and its still forever and a day to refuel.

This was my initial assessment of the problem. The tank inlet was 1.25" ID so my thought was to increase that to 2". Just to share my info, I'm using a re-pop steel 69-72 blazer tank (< $200). My 'inlet' is the original tank inlet from a stock 'in-cab' 68 tank that I cut off flush @ the tank w/some fabbed 2" fuel fill piping & a 2" ID fuel fill hose to connect everything (< $40). The inlet to tank inlet distance is < 24".

In order to route my fill line to the blazer tank & keep it out of the way, I'll need to fill the tank from the inlet located just beside the inner bedside wall. This requires a 90° bend (2" mandrel bend tubing). I figured I would run a vent tube from the vent port adjacent to the tank inlet back up to the inlet/cap area but my continued research says this still may not be the answer.

It's sounding like this is an all to common thing we 'put up with' but it sure takes away from the experience of owning/driving older iron....

[VA72C10]

Good eventual FAQ thread....once a firm solution is found

[johndawelder]

I put a 25 gal. blazer tank under the bed where the spare tire was.I fill the tank with the tail gate down and have no issues filling.I ran 1/2 inch steel line to the front with an inline elecric pump and filter.

[SCOTI]

Originally Posted by johndawelder

I put a 25 gal. blazer tank under the bed where the spare tire was.I fill the tank with the tail gate down and have no issues filling.I ran 1/2 inch steel line to the front with an inline elecric pump and filter.

As in through the bed floor straight into the tank or w/a fill line?

[Palf70Step]

I have an original 72 Blazer tank (neck is different than the repops. I grafted a filler door from a 94 C1500 into the bed., welded some pipes to adjust it up to the newer diameter fill pipe. Fuel line is 3/8 from tank up in the passenger side rail with a 95 C1500 in line fuel filter.

I can't say how it fills/works yet as the truck is still in the "assembly" process.

[71meangreenc10]

Heres what mine looks like.

Smitty

[vasquezmrysvll]

i used a tank from a 76 1/2 ton van, with a stake pocket filler (same as johns) 1.5" hose coming off the tank, to a 1.5" pipe with a 90 degree crush bent using a BFH and torch. i have one 3/8 vent 2'' below the fuel cap and one 1/4 vent to let the tank breath while consuming fuel. at the pumps i can let-er-rip with no problems. i guess what im trying to say is 1.5'' tube is more than adequate if vented properly.

[vasquezmrysvll]

make sure everything is down hill, any elevation in the plumbing will back up flow

[SCOTI]

Originally Posted by vasquezmrysvll

make sure everything is down hill, any elevation in the plumbing will back up flow

That's part of my concern.

The tank is raised slightly since the truck will be pretty low & the fill line will run just below the bed floor. Between the 2 points, the slope is < 5° (not level, but not much slope either).

I'm starting to think I'll need to re-work the inlet & just do a straight shot up to the bed floor w/a flip up gas goor/cover although I prefer not to if possible.

[PICKMUP]

Originally Posted by 71meangreenc10

Heres what mine looks like.

Smitty

Do you have enough tire clearance with the fill pipe? Is truck lowered?

[Hart_Rod]

Originally Posted by SCOTI

That's part of my concern.

The tank is raised slightly since the truck will be pretty low & the fill line will run just below the bed floor. Between the 2 points, the slope is < 5° (not level, but not much slope either).

I'm starting to think I'll need to re-work the inlet & just do a straight shot up to the bed floor w/a flip up gas goor/cover although I prefer not to if possible.

If you are going to rework it, why not do a side marker fill or taillight fill like HuggerCST?

[SCOTI]

Originally Posted by Hart_Rod

If you are going to rework it, why not do a side marker fill or taillight fill like HuggerCST?

It's a 64 short fleet w/a steel floor on a 68 frame. Plus, the blazer fill port is just above the frame rail. Going through the light socket & having a 90° bend under the floor still yields the same < 5° slope....

[Hart_Rod]

The side marker fill will get you about 30 - 45 degrees. It's a little tighter, but still doable.

[SCOTI]

Originally Posted by Hart_Rod

The side marker fill will get you about 30 - 45 degrees. It's a little tighter, but still doable.

No side markers on 64's though.

[71meangreenc10]

Originally Posted by PICKMUP

Do you have enough tire clearance with the fill pipe? Is truck lowered?

Plenty of clearance, would be close if it was lowered.

Smitty

[Hart_Rod]

Originally Posted by SCOTI

No side markers on 64's though.

... ...

[chevydog66]

Mine is a lot like this one, except I used a 20 gal. aluminum tank from Summit.
http://www.johnnyrods.com/67truck/

[SCOTI]

Originally Posted by chevydog66

Mine is a lot like this one, except I used a 20 gal. aluminum tank from Summit.
http://www.johnnyrods.com/67truck/

I like the idea but don't want to do any exterior paint/body work (the floor w/get bed liner).

[vasquezmrysvll]

Originally Posted by chevydog66

Mine is a lot like this one, except I used a 20 gal. aluminum tank from Summit.
http://www.johnnyrods.com/67truck/

mine too, but as i stated earlier my tank is from a 76 chevy van

[Fitz]

I took the cowards way out and put the fill up through the bed floor. Fittings are for suction line, NHRA rollover valve and fill. The fill is a boat flush deck fitting...easy to get to, easy to fill, no annoying punp shutoffs. The tank is an Early Classics Stainless Steel tank.