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Lets talk fuel tank(s) for me...

RootBreaker

RootBreaker

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Ok so this isnt as easy as one would think... this gets complicated. let me shake my head and empty my thoughts out and all on the table...


current:
dual saddlebag tanks - wiring works, everything works but tanks are rusted out.

Plan (non tank related but still tank related)
Motor - keep my current setup and just stay carb (or tbi)
Motor - 8.1L - ok need a new fuel pump

Tanks
Stock - replace both saddlebags with replacements

Pro
... stock everything is there and works now
... 2 x 20g tanks

Con
... if i put a Body lift on - i know i know.. just hear me... I have to put braces around it NJ law
... hang low
... 1 plastic costs as much as 2 metal....

Suburban
Pro
... 40 gallon
... 1 tank in plastic

Con
... need to run new fuel lines, etc
... need new float assembly, etc...
... custom mount between frame
... how to run fill tube?

now with this thinking... I am really leaning towards a 8.1L mainly for fuel injection, computer controlled... reliability.
IF i go that route I would like to do a in tank fuel pump/float assembly.


so guess the question(s) is...

  1. Is there hate for the saddlebag tanks and replace them?
  2. what fuel pump/float assembly to put into what tank even if I keep the SBC 350 for now? understanding a regulator is needed

lets start there! hah.. thanks..
 
First is figure out what tanks you are going to run. If the dual tanks are the option, you are going to need two pumps.

The EP381 is the recommended pump to go with '87-91 TBI sending units for "high pressure" EFI, but you don't want to buy two if one is all you need.

I'd add up the cost of running carbed with a regulator, vs. sticking with what works for now. That regulator will be useless to you once you get EFI, so that has to be factored in.
 
There was just a thread on here about raising the saddle tanks by redrilling the mounts to raise them an inch. Would NJ still require braces if you did that?
 
I plan on 1 efi tank with sender and said pump on it from above post .

then 2nd tank will be on a toggle switch for a transfer pump to the efi tank . and will have a :eek1: BRIGHT LED :eek1: to light up and keep you focused on fuel transfer to not over fill and spill gas on primary tank .

this is the cheapest way around the efi and twin tank switcher valve that was never designed in our factory combos for 60+psi even in factory tbi .
 
rampage said:
There was just a thread on here about raising the saddle tanks by redrilling the mounts to raise them an inch. Would NJ still require braces if you did that?
Click to expand...


the deal is they cannot hang below the factory body line. I dont see myself putting a body lift on and have never punctured a tank and dont really wheel now... so this was just a thought about getting rid of the saddles.

sweetk30 said:
I plan on 1 efi tank with sender and said pump on it from above post .
then 2nd tank will be on a toggle switch for a transfer pump to the efi tank . and will have a :eek1: BRIGHT LED :eek1: to light up and keep you focused on fuel transfer to not over fill and spill gas on primary tank .

this is the cheapest way around the efi and twin tank switcher valve that was never designed in our factory combos for 60+psi even in factory tbi .
Click to expand...

years ago I had a manual switch where I had to crawl under my truck and rotate it... to switch tanks... it sucked...
i dont think i want to go a transfer way...
 
so anyone have a pic of a EP381 setup on the float, etc? i thought it was going to look like the one that was in my 1996 camaro...

im figuring something like this? which is a quick google for my camaro...

2009-11-12_202543_4.gif
 
ok found these...

IMG_5602.jpg




best here is... on ck5..

Larry said:
In that case you need an AC Delco EP381 for the higher pressures of sequential port fuel injection. The 8.1Ls in my K10 and Suburban use TBI fuel tanks, TBI sending units with the EP381 pumps (1996 5.0,5.7 and 7.4L pump). When I initially ran my 8.1L in the K10 in an MEFI-4 ECM (Marine and RamJet) it required lower pressure of 43 psi like an old TPI engine so I ran a EP241 to run that (EP241 is what was used to run TPI cars). From experience I can assure you an EP241 will not have enough nut to run a sequential port injected engine properly as it is only good for about 55psi while the EP381 will run up to 80 psi (and possibly higher). Both of my 8.1Ls run at 65 psi. They just seem happy at higher pressures.

Here is an EP381 mounted to the ’89 Suburban TBI sending unit.
16669451427_1178baf786_c.jpg
Click to expand...
 
hmmm so now im leaning towards a 31gallon suburban tank and just 1 tank. 40g just seems to big for my needs and also taller and would require more mods to get between the frame.
 
With some proof of concept, I think you might be able to get away with running one pump, and dual tanks.

Plumbed right, the "primary" tank (the one with the pump) can be setup to siphon fuel from the secondary tank. No valves needed.

I talk about it here, including that I got a mockup working: https://ck5.com/forums/threads/idea...witching-solenoid-on-dual-tank-trucks.317308/

Some valid concerns with the idea, and I really can't wrap my head around what happens with the return line, whether or not it could overfill the tank and cause issues that way. I suspect that would have to be figured out, probably a Y on the return line, running to both tanks.

A single tank is far easier, as long as you can set it up pretty cheaply and easily. If you are running an 8.1L at some point however, you probably won't think 30G is all that much lol, depending on your usage of the vehicle.
 
I'm basically in the same boat as you, only difference is I'm looking at aftermarket EFI but still requires same high pressure fuel system as an 8.1L would.

First, if you replace the saddle tanks you'll want 87 and newer so you get the baffled tanks. Here are the 3 choices I considered.
  1. One option is to put the EP381 in both tanks AND you need a high pressure fuel tank selector valve.
  2. As mentioned already, put the EP381 in just one tank and use the other tank as an auxiliary tank. Problem is you will still need some sort of pump in the auxiliary tank to transfer fuel or the siphon method dyeager535 mentioned.
  3. Install Burb/K5 tank
Currently I'm leaning towards #3. The filler hose will be routed up behind a tail light. The tail light will hinge open for access. Don't have the thread link handy but I found a write up on another forum thru a Google search.

Since I have TBI, both saddle tanks have in-tank pumps. Everything functions properly on my rig. I'm actually thinking about using a smaller 25gal K5 tank and using BOTH saddle tanks as auxiliary tanks that will dump into the K5 tank. That gives me 65gal fuel capacity.

Another option if I'm understanding your current set correctly. You have a carb'd motor with the pump mounted on the motor, correct? I would think you could feed an 8.1L with a frame mounted pump. I would be tempted to go this route if I didn't already have in-tank fuel pumps.
 
mrk5 said:
I'm basically in the same boat as you, only difference is I'm looking at aftermarket EFI but still requires same high pressure fuel system as an 8.1L would.

First, if you replace the saddle tanks you'll want 87 and newer so you get the baffled tanks. Here are the 3 choices I considered.
  1. One option is to put the EP381 in both tanks AND you need a high pressure fuel tank selector valve.
  2. As mentioned already, put the EP381 in just one tank and use the other tank as an auxiliary tank. Problem is you will still need some sort of pump in the auxiliary tank to transfer fuel or the siphon method dyeager535 mentioned.
  3. Install Burb/K5 tank
Currently I'm leaning towards #3. The filler hose will be routed up behind a tail light. The tail light will hinge open for access. Don't have the thread link handy but I found a write up on another forum thru a Google search.

Since I have TBI, both saddle tanks have in-tank pumps. Everything functions properly on my rig. I'm actually thinking about using a smaller 25gal K5 tank and using BOTH saddle tanks as auxiliary tanks that will dump into the K5 tank. That gives me 65gal fuel capacity.

Another option if I'm understanding your current set correctly. You have a carb'd motor with the pump mounted on the motor, correct? I would think you could feed an 8.1L with a frame mounted pump. I would be tempted to go this route if I didn't already have in-tank fuel pumps.
Click to expand...

Scott, would you mind posting that link? This is what I'm going to do with mine.
 
I have a 1" ORD body lift on my crew cab with saddle tanks, and the only part of the tank that hangs below the body is the plastic tank shields by about less than an inch. If I took the plastic tank shields off the tanks would be almost level with the body. The later model 80's saddle tanks come with a tank brace style that wraps all across the bottom and sides of the tanks, unlike 70's years tank braces, which only wrapped around the inner side and half the bottom of the tank. Early trucks only came with the inner half of the bracket illustrated below, but later years (because of side impact crashes) came with both the inner and outer half of the brace pictured.

0051.jpg
 
mrk5 said:
I'm basically in the same boat as you, only difference is I'm looking at aftermarket EFI but still requires same high pressure fuel system as an 8.1L would.

I actually just want to go some type of injection and found a tbi setup for $1000 that they say would work and they can program for my setup. For an extra bit of cash I could just go 8.1L... and why not .my truck is barely EVER driven. I am 43 and kids in so many sports. in about 8 years I will have a good 5-10 years before Im done with working on trucks. Gotta expect getting old. One of my kids or both will inherit my truck (hopefully before I kick) and would love to get the 8.1L just ..... bcuz!!!!!!!

but with that I am in 2 different thoughts...

First, if you replace the saddle tanks you'll want 87 and newer so you get the baffled tanks. Here are the 3 choices I considered.
  1. One option is to put the EP381 in both tanks AND you need a high pressure fuel tank selector valve. - Yup. I make good money and tired of migshifting things and this is a good choice.
  2. As mentioned already, put the EP381 in just one tank and use the other tank as an auxiliary tank. Problem is you will still need some sort of pump in the auxiliary tank to transfer fuel or the siphon method dyeager535 mentioned. - to each is their own. I see this as a workaround (migshift) and not something I want to do anymore. Just sayin and not bashing if you do it.
  3. Install Burb/K5 tank - while I do like my dual 20g tanks as I said right now I dont really drive far BUT if I want to I wouldnt mind and yes with 8.1L and what 9mpg... 40 gallons wont go far! so still a good choice as well.
Currently I'm leaning towards #3.
im on #1 mostly. Possibly 3... but I can get 1 tank and do 1 pump if I wanted to go the dual route and later do the other.

The filler hose will be routed up behind a tail light.The tail light will hinge open for access. Don't have the thread link handy but I found a write up on another forum thru a Google search.
Ive seen this. Awesome idea. Uses hinges and hides like a 57 chevy bel air did...

Since I have TBI, both saddle tanks have in-tank pumps. Everything functions properly on my rig. I'm actually thinking about using a smaller 25gal K5 tank and using BOTH saddle tanks as auxiliary tanks that will dump into the K5 tank. That gives me 65gal fuel capacity.

Another option if I'm understanding your current set correctly. You have a carb'd motor with the pump mounted on the motor, correct? I would think you could feed an 8.1L with a frame mounted pump. I would be tempted to go this route if I didn't already have in-tank fuel pumps.
Yes I am carbed with a napa fuel pump down near the tanks right next to the dual tank selector valve. I have thought of just going with a good high pressure fuel pump and 2 new tanks and reuse even my floats. They work. my tanks are rusted out.

my current low pressure fuel pump from Napa...

20160520_101253 by Jeffrey Riggs, on Flickr
Click to expand...

replied above.. thx for your thoughts.. yes im in the same boat....
 
RootBreaker said:
replied above.. thx for your thoughts.. yes im in the same boat....
Click to expand...
I can see the benefits of an EP381 in each tank with the high pressure valve because it keeps the truck more like factory. Really the big reason I'm leaning towards a K5/Burb tank is because it is a bit of a pain to have to fill one tank and then move the truck to fill the other tank. In all reality if I do the single tank I'll probably just remove the saddle tanks altogether. Just sounds cool being able to carry 65 gallons of fuel, doubt I'd ever fully utilize the ability to do it.
 
When I replaced the saddle tanks in my truck I used AC/DELCO EP377 (MAX 30 PSI) in each tank because I kept the TBI, and added an adjustable fuel pressure regulator to it.
 
RootBreaker said:
years ago I had a manual switch where I had to crawl under my truck and rotate it... to switch tanks... it sucked...
i dont think i want to go a transfer way...
Click to expand...

no goofy electric pump sucking fuel from extra tank and dumping it in to the efi pump tank via a switch on the dash .
 
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