Can’t decide on single or dual tanks

[boltbrain]

I'm coming along a little late but still want to give my input on 2 tanks vs one rear mounted tank. I had to cross this bridge a few years ago.

My truck was a factory single tank, and had developed a leak. I was not happy with one 20 gallon tank, I mean unless you hammer the tank on E there is what about 15 usable gallons. That's something like 200 miles on a good day on the highway and less than 150 on a bad day with a loaded trailer even less. That was totally unacceptable when making a couple hundred mile journey for feed. In the end I decided to add a second 20 gallon side saddle tank. Main reasons were I felt that the two side saddle tanks spread the weight out better, it was an simpler install, and nets me a total of 40 gallons. I start with two full tanks hammering the left tank on E knowing that the right is full, plus run that to a 1/4 I've got a solid 35 usable gallons. That's about 450 miles on a good day 350 on a bad day. I'm not disparaging the the rear tank swap at all I came close it and there are good reasons for doing it. But in the end I just didn't feel that the work involved was worth while to gain 11 gallons, where as I could bolt on stock components to gain 20 gallons and get 40 gallons total.

The switching valve for a two or even if a guy wanted a 3 tank system, is not really an issue anymore. In the old days there were units, particularly the one wire valves that were prone to failure. The newer units produced by Pollak and often sold under the brand Wells is very reliable. Far more reliable than any electric transfer pump could be. Keep in mind we are dealing with fuel here, and if I guy home brews a transfer tank system and there is a large amount of fuel spilled or fire involved you could be on the hook for the clean up / damages.

Like @Grit dog said a 35 - 40 year old, or even 20 year old replacement valve fails and guys get all upset about reliability. Show me an aftermarket electric fuel pump (frame rail type not injection) or electric transfer pump that age that still functions. It's just like the guys that whine and complain about there rubber fuel lines breaking down from ethanol. Yea, all know ethanol if hard on rubber fuel lines but after 35 - 50 years those lines are shot from age! I'm just saying. At least with the switch valve a guy could lay under the truck and swap ports on the valve to manually change the tanks. With an electric transfer pump if it goes bad your out of luck. Just my opinion obviously but maybe some food for thought on that subject.

Thanks, agree all around. There are pros and cons whichever. I am not so averse to using two. I’d prefer a manual valve but if they’re not available, yes just replace them often enough. But you don’t mention safety. I’ve been rear ended twice and sideswiped once ( parked). One rear ender was by a texting driver. It’s more dangerous on the road these days. I have other vehicles so it’s not a major factor but I’m thinking if someone side swiped a saddle tank, it could open like a sardine can and with sparks. I’m surprised there hasn’t been much mention of the lethality. I mean, there’s a reason they don’t design them that way anymore. I suspect that owners don’t much think if it when the tanks are hidden ( and slightly protected) by stock boxes.
On further consideration, until I see or think up a good fail safe plan I don’t want a transfer of tank to tank. I’m keeping the 4 wires that come from the dash and went to the valve.

 

[boltbrain]

I think the Suburbans also came with a 40 gallon rear tank. I may end up getting one some day. They’re available from LMC etc. Probably what I should have done. Just like having my spare there. Not many good alternatives for spares on a flatbed. It was in front of the engine but that’s a hassle for working on the engine. Maybe hinge it up there. Hmmm

 

[SirRobyn0]

Thanks, agree all around. There are pros and cons whichever. I am not so averse to using two. I’d prefer a manual valve but if they’re not available, yes just replace them often enough. But you don’t mention safety. I’ve been rear ended twice and sideswiped once ( parked). One rear ender was by a texting driver. It’s more dangerous on the road these days. I have other vehicles so it’s not a major factor but I’m thinking if someone side swiped a saddle tank, it could open like a sardine can and with sparks. I’m surprised there hasn’t been much mention of the lethality. I mean, there’s a reason they don’t design them that way anymore. I suspect that owners don’t much think if it when the tanks are hidden ( and slightly protected) by stock boxes.
On further consideration, until I see or think up a good fail safe plan I don’t want a transfer of tank to tank. I’m keeping the 4 wires that come from the dash and went to the valve.

I don't disagree with the potential for danger on the side saddle tanks, but keep in mind that the generation of truck prior to these had the fuel tank in the cab, so in my mind the saddle tanks were an improvement over that, at least the fuel is not in the cab.

You can read some info on it hear >> https://www.autosafety.org/history-gm-side-saddle-gas-tank-defect/ << But even today there is a big debate on how much danger there really is. Like I said to me I feel like it is better than having it in the cab so that makes me feel safe about it.

No mater where a fuel tank is located there is always going to be some risk of fire in a crash. At least in saying with the OEM setup VS home brew your not personally responsible for the design if there is a major issue. JMO.

 

[TotalyHucked]

I know I need overdrive, just don’t know which engine to look for. Or which engine/tranny combo, that is. I need lots of torque. Not that worried about mileage, but it’s preferred. I like to blast throo snow drifts with four chained wheels. And I’m tired of trying to start diesels below zero. How torky is the 6.0 and is it harder to swap in because of it’s size?

I'm an LS swap guy. It ain't cheap (unless you buy a wrecked truck and sell everything off that's not needed to recoup), but it's not terribly hard. 6.0s make good torque, especially if you get an LQ9 thanks their flat top pistons/more compression. They definitely get better fuel mileage than and old SBC or BBC.

 

[boltbrain]

Thanks. I’ve watched a few YouTube vids on it and with that kind of help plus this forum it seems not too difficult. I have a decent machine shop for it. Also considering just buying a early 2000s 2500with a 6.0 and a five speed. But the drivetrains aren’t hard to come by either. I will read up on the LQ9

I'm an LS swap guy. It ain't cheap (unless you buy a wrecked truck and sell everything off that's not needed to recoup), but it's not terribly hard. 6.0s make good torque, especially if you get an LQ9 thanks their flat top pistons/more compression. They definitely get better fuel mileage than and old SBC or BBC.

 

[boltbrain]

I don't disagree with the potential for danger on the side saddle tanks, but keep in mind that the generation of truck prior to these had the fuel tank in the cab, so in my mind the saddle tanks were an improvement over that, at least the fuel is not in the cab.

You can read some info on it hear >> https://www.autosafety.org/history-gm-side-saddle-gas-tank-defect/ << But even today there is a big debate on how much danger there really is. Like I said to me I feel like it is better than having it in the cab so that makes me feel safe about it.

No mater where a fuel tank is located there is always going to be some risk of fire in a crash. At least in saying with the OEM setup VS home brew your not personally responsible for the design if there is a major issue. JMO.

It seems to me, but I am no expert, that fire is maybe less the risk than an explosion. Fumes in a container with a little gasoline with a spark is more like a bomb than a fire. I should probably google about the risk on the Chevy trucks. Pretty slow Internet here tho.
As to liability, yes I may be liable but first there would have to be proof the design caused the explosion and that’s not gonna happen because (a) it would only be an issue from an accident not caused by me and (b) my design is safer than the factory and (c) the tank is surrounded now by more structural steel than before and less likely to cause the hypothetical injury. And (d) I’d probably die too

 

[SirRobyn0]

It seems to me, but I am no expert, that fire is maybe less the risk than an explosion. Fumes in a container with a little gasoline with a spark is more like a bomb than a fire. I should probably google about the risk on the Chevy trucks. Pretty slow Internet here tho.
As to liability, yes I may be liable but first there would have to be proof the design caused the explosion and that’s not gonna happen because (a) it would only be an issue from an accident not caused by me and (b) my design is safer than the factory and (c) the tank is surrounded now by more structural steel than before and less likely to cause the hypothetical injury. And (d) I’d probably die too

I'm not trying to start an argument, and I do understand the thinking "it would only be an issue from an accident not caused by me" That's not necessarily true. I know this is a little different but in most if not all states, lets suppose your rolling along without insurance and someone hits you, you can bet your getting a ticket for no insurance. If you cruising along and someone hits you and your drunk but did not cause the accident they will most certainly pop you with a DUI and in this state if it's your third time it's you license as well. They aren't going to care if your not at fault. I think the same thing would apply if a home brew setup caused a fire. If by saying "my design is safer than the factory" Yes, I agree the single tank inside the frame your running probably is and you'll likely never have an issue from it, but if we are talking about the transfer pump idea, which is what all my negative comments have really about then I disagree. And that maybe the problem. I'm arguing a person is better off with the saddle tanks and a valve than tanks that involve tank to tank transfer, not a single tank conversion. I agree a single tank conversion is very unlikely to cause an issue. Sorry if I was unclear about that.

 

[boltbrain]

I'm not trying to start an argument, and I do understand the thinking "it would only be an issue from an accident not caused by me" That's not necessarily true. I know this is a little different but in most if not all states, lets suppose your rolling along without insurance and someone hits you, you can bet your getting a ticket for no insurance. If you cruising along and someone hits you and your drunk but did not cause the accident they will most certainly pop you with a DUI and in this state if it's your third time it's you license as well. They aren't going to care if your not at fault. I think the same thing would apply if a home brew setup caused a fire. If by saying "my design is safer than the factory" Yes, I agree the single tank inside the frame your running probably is and you'll likely never have an issue from it, but if we are talking about the transfer pump idea, which is what all my negative comments have really about then I disagree. And that maybe the problem. I'm arguing a person is better off with the saddle tanks and a valve than tanks that involve tank to tank transfer, not a single tank conversion. I agree a single tank conversion is very unlikely to cause an issue. Sorry if I was unclear about that.

Thanks for clarifying. No argument, ( not that arguments are bad things) I’ll clarify my comments which agree with yours. I meant that I won’t cause an accident because I don’t drive drunk, for one thing. I could’ve added I won’t be without insurance, either. On the two tanks with transfer pump. I said in a post today that I decided to abandon that idea for safety reasons. Don’t see a reliable way to do it. Thanks for your thoughts.

 

[SirRobyn0]

Thanks for clarifying. No argument, ( not that arguments are bad things) I’ll clarify my comments which agree with yours. I meant that I won’t cause an accident because I don’t drive drunk, for one thing. I could’ve added I won’t be without insurance, either. On the two tanks with transfer pump. I said in a post today that I decided to abandon that idea for safety reasons. Don’t see a reliable way to do it. Thanks for your thoughts.

I missed that post. At work sometimes I don't get to read as thoroughly as I'd like. I've rather enjoyed our conversation personally, I just like to stuff like not trying to cause an argument, because I've had some people fly off the handle at me just because we don't see eye to eye, and I'm just getting to know you! Take care, I hope you continue to hang around here!

 

[Ricko1966]

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Apples to Apples a 5.7 small block with modern engine management. A 5.3 ls and a 6.0 ls with modern engine management.

 

[TotalyHucked]

Thanks. I’ve watched a few YouTube vids on it and with that kind of help plus this forum it seems not too difficult. I have a decent machine shop for it. Also considering just buying a early 2000s 2500with a 6.0 and a five speed. But the drivetrains aren’t hard to come by either. I will read up on the LQ9

You might even get lucky and find a low mile unit you don't have to build. I bought a 104k mile 5.3 for mine. Rebuilt the top end, slipped in a cam, inspected the bottom end when I had the oil pan off and slapped it back together with no machine shop visit. My tuner figures I'm at ~425hp or so. A 6.0 would be ideal for your truck but a 5.3 would still be worlds more powerful than the old small block and be more efficient too. 6.0s cost an arm and a leg down here, that's why I went 5.3.

 

[SquareRoot]

They were pretty milqutoast.

Well.....I can't be the only one?

 

[SquareRoot]

Someone mentioned LS and horsepower. I just learned there's a company making Hemi heads for LS engines. Yup. On a stock 5.3, it makes 425hp. Who knew!

 

[rpcraft]

To answer the question about gas mileage in a v6 vs v8, I once had a 2003 dodge ram, shortbed single cab with a v6. Driving from Dallas to Houston it would get at best 13 to 14 mpg, without fail. I test drove a hemi dodge that was a 2005 and quadcab, shortbed. It averaged 18 to 21. To my best determination it was because the v8 had enough torque to where it did not shift down every time it hit a rise in the highway. They both had the same rear diff gears and 5 speed transmission. Also when towing Torque allowed it to not shift down unless it was a heavy load and on a hill thanks to the tow/haul mode. I will never get a v6 option in a full size truck again. It will only be more efficient if your overall drive is city type driving in short stretches and when you hook a trailer or a load to that truck you will miss what the V8 has, which is torque. Now, not to take away from a V6 though. My daily driver is a Nissan Frontier with the 4.0 in it. Aside from not having a ton of passing power, with a trailer brake it does tow pretty good though.... I was gonna drive the C10 from my Dad's estate to mine but then I took a look at the tires, lol. I'm pretty sure I averted multiple roadkill scenarios much less saving some gas.

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[TotalyHucked]

Someone mentioned LS and horsepower. I just learned there's a company making Hemi heads for LS engines. Yup. On a stock 5.3, it makes 425hp. Who knew!

Yeah, they've been around for a long time, I believe Arias was the first to do them