Fuel (pump) for discussion

Reprise

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So today, I figured out that my Sierra's new (but recurring) 'crank / no start at initial try' isn't due to a tuning issue, etc. - it's likely an issue with the check valve in the fuel pump going bad (fuel system loses pressurization). Solution is to apparently replace the pump. Which, while it's an issue... is also an opportunity. And while I could get by in the short term by pressurizing before starting (like we do when depressurizing for fuel work, etc.), I think I'd prefer to just fix the problem, rather than have to remember a workaround, every time I get in the truck.

I know it's easy enough to drop the tank & put a like-for-like stocker back in (and from what I recall of everyone replacing in their 360s, it's "Bosch, ACDelco, or don't even bother doing it"). There are also 'plain pump' assemblies (of which Walbros is one; I'll get to them later).

The stock pump for my truck is listed at about 60-ish gph max; normal duty cycle comes out to about half of that.

I'm thinking about getting a beefier pump - not that I need it now, but if I add boost (turbo) later on, that's one more thing I won't have to replace, when the time comes. So, I figure... replace it now.

Doing some reading, the flex fuel-capable stockers are supposed to flow really well - 600-700 HP trucks do just fine with them. So that's another option (although I'll have to do the homework on adapting one to my '03, which has a 'return' fuel system w/ the regulator on the intake; those went away in '04, and the only 'classic' that ever got a FF-capable pump was the '07. But I know *someone's* done it, so I don't have to reinvent the wheel - just find their notes / how-to.

The 'go-to' option for those running boost on full-size trucks seems to be a Walbros brand pump -- and those apparently come as 'just' the pump, not the entire module. I still have a lot of reading to do in this area. These are racing (?) pumps; 300-450 LPH and up. I don't think I need that much flow, to be honest, so this option's going to be on the back burner, right now.

I already have a brand new set of FF-capable 50lb injectors (Delphi), waiting to be installed (the stockers are rated at 25.5, and they'll eventually have to come out. More on this later, when I get ready to swap the intake.) Right now, I'm still running the stockers, and not noticing any bogging / evidence of fuel starvation, etc. I'm also not romping hard on the motor for another 500 miles, yet. But since the fuel pump issue has now come to light, I figure to get that upgraded now.

I also want to be able to run E85 on occasion, so a FF-capable pump would help with this. I'd still need to get a fuel composition sensor to make E85 work, but that's pretty much all I'd need (and enable it in a tune, of course)

Yes, I realize I really didn't ask a 'question', here. If you have input, feel free to share (including if having that extra flow will cause an issue w/o really 'needing it', at the moment). Last time I dealt with a fuel pump was the mechanical type, on a SBC, about 30 years ago. So I'm a bit behind the curve, here.
 

Mooseman

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Certainly an interesting project. But I wonder if this would be a case of "If it ain't broke...". One video I watched from Eric the Car Guy was "Don't modify your daily driver", or the way I interpret it, "Don't f*ck with it if you need it to be reliable". I went through this with my '02 and efans. I reverted back to a clutch fan and the only mod really after that was a thermal clutch, which was introduced to these trucks on '08.

What would be the benefit? Although E85 vehicles have been available here, the fuel is as rare as albino moose. Is it worth the trouble?
 
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Reprise

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Is it worth the trouble?

Well... I think it *could* be...

First, the impetus for a more capable pump is to combat potential fuel starvation (using E0 or anything else). So even if I don't get something FF-capable, I'm still planning for that, for the day if / when boost is added (which isn't going to be 'tomorrow').

Now... w/ regard to E85...

I can actually find it locally, here. Not that I'm wanting to *run* it here.

Since it raises octane, I figure it would be nice to have when towing in mountainous areas.

Out west, I noticed on my (all too frequent) fuel stops that:
- RON gets decreased by 1-2 points, at elevation.
- E85 was available (w/ its higher rating)
- And as we all know, there's less air / oxygen content, especially as you go above, say, 8000 ft. elevation. That's the reason the octane gets decreased, relative to lower altitudes.

Finally, I'm doing a bit of future-proofing w/ regard to availability.
We're starting to see E15 become more available here. And I think TPTB want to switch the E10 supply over to E15.

Between E10 / E15 / E85 / Diesel, it's getting to be a bit confusing at the pumps! (ok, I'm exaggerating... but we really do have stations with all of those blends - I think there are 5 (!) available at one station, but I forget what the last one is).

As time goes on, and as the fleet switches away from gasoline, I think this could be accelerated, such that we start seeing more and more ethanol (or something), and less gasoline in the fuel. I may be off-base here. But it's good to be prepared (something that I always strive for).

So, that's my thinking. And I'm also leaning toward a stock FF-capable pump b/c I figure I'll have fewer potential mods to do to make it work, and b/c it'll likely be cheaper than one of those aftermarket quasi-racing solutions.

Hopefully, I didn't get everyone 'lost in the weeds' again w/ E85, describing all of this.
 
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mrrsm

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Reprise

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Yep - I've gone through many of the entries in that series (and, btw, they use a 'template' to kind of format them similarly -- which is fine). I have some of them bookmarked; IIRC, this series is where I started looking for a tow cam. And I know my choices of which timing chain, lifters, etc., to use were definitely influenced by this series.

So, I've definitely isolated the issue to the check valve -- as long as I turn the key to 'on' and let it prime before starting, it fires up in about 1 sec. And it runs fine from there. The 'drainback' doesn't take long -- in as little as 5min. So it's an 'every start' thing, until I replace it.

On to the replacement... I've since found out that I could *just* replace the pump subassembly with a new one, if I wanted, and reuse the rest of the module. I'd need to do some wire cutting / splicing, but that doesn't scare me off, at all. Neither does modifying the 'bucket' that it sits in, as long as I can find some guidance on what has to be done (I know I need a dremel, but that's about it, right now).

The article you referenced mentions that a tank replacement might be advised if putting in the entire fuel pump module (which would steer me further toward *not* using a factory FF module, although, me being 'me', I'll take a look to see how the tanks differ between the GMT800 CCSB and the 900 CCSB.):compu-punch:

The other thing that the article mentioned (and struck me funny, as I had just been exploring this on my own), is using a 'dry shot' nitrous system ('dry' is where no extra fuel is injected with the nitrous, as opposed to a 'wet shot'). Anyway, the article mentions that a 30-50HP dry shot could be safely added to a stock bottom end. For my needs (getting up the grade), maybe that's something I should explore further.

But -- for now, it looks like a new fuel pump (of some sort) is definitely going to be in my near-term plans. It was working fine before the truck sat for four months, so I have to wonder how that affected the check valve, whether it was non-use, or a contaminant of some type getting into the valve... who knows. But the truck is running well, otherwise, so I'm not perturbed too much about replacing the pump, since I knew the odds were that I was going to want / have to, anyway.

Found a deal on some turbo gear on CL; playing 'text tag' with the seller. We'll see what happens there. I may be learning to weld, after all. :yikes:
 

mrrsm

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I'm as enthusiastic as the next Member for all of YOUR Performance Enhancement Projects as you are... so I'm loathe to dampen your motivation here in the slightest.

BUT... the primary considerations that needs your attention well before any thoughts about Augmenting the Power of The Motor using Super-Charging, Turbo-Charging or in this case... the Use of Nitrous-Oxide are that you REALLY need to Take a Big Step Backwards at the moment until you can become completely grounded in What This Technology is capable of doing to your Stock Engine.

The Use of Nitrous-Oxide in ANY Un-Modified Engine centers around these Problems:

(1) Your 6.0L Engine Does NOT have Forged Pistons AND Forged Connecting Rods.

(2) Your 6.0L Engine Does NOT have enough Compression Ring Gap Clearance right NOW to avoid Damage from Detonation that will either Blow Holes through the Piston Heads ...or have the Stock Configured Compression Rings cling to the Cylinder Walls and literally Pop the Piston Heads right off of their upper Piston Boss areas... Like Bottle Caps from Shaken Up Pepsi-Colas!

(3) Engines that use Nitrous-Oxide MUST be Purpose Built if that Motor is expected to behave right and hold together as a Reliable Daily Driver.

(4) These Problems are The RULE and NOT The Exception when using Nitrous-Oxide. It only takes ONE Mis-Dial in the amount of Nitrous-Oxide getting injected into the Intake and Your Motor Might Grenade and Leave You WALKING with Your Thumb Out.

(5) Avoid relying upon articles and information being published and supported by the people with the Nitrous Bottles, Piping and Intake Manifold Gear to Sell and who Don't Give a Tinker's Damn about whether or not their Gear will work in your Truck. If it Blows Up ...it will ALWAYS be the Owner's Fault. Instead of watching the "Pie In The Sky" Videos for inspiration... Watch the ones showing "The Average Joe" accidentally Blowing Up His Engine... and PLAN your Defenses as an Engine Builder around THAT Reality. Sit Back...and WATCH how just a Little Too Much Tinkering to Get MORE POWER can suddenly Go Sideways...


'Nuff Said...
 

Reprise

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Originally, I was going to reply to this, point by point. But that would be petty of me.

Reading your reply, one wouldn't be faulted for thinking I was a total neophyte. But we both know that's not the case. And the video you linked to is really an "apples to oranges" comparison.
The purist in me would say "don't you EVER compare a F**d engine to an LS!" :dielaugh: But it's about more than engineering -- it's also their (VOP) stated purposes, vs. mine. They're *trying* to blow the motor up, and state so, at the beginning of the video.

I really don't have to say this... but we both know the LS is a strong motor, and can handle a LOT of modification, even in stock form, with cast internals. I've seen a junkyard (!) 6.0L truck motor (iron block) with a stock cast rotating assembly pull over 1500HP (crank) on a dyno, repeatedly -- without blowing up. How long would it live? Hard to say -- at that level, it's basically a race engine, and those get torn down / refreshed on a regular basis. But it did it, and it ran fine afterwards. And it wasn't done by some yahoos, like in the above video.

For what I want to do, and the way I use it -- I wouldn't hesitate to put 8-9 pounds of boost, or a 30-50 shot on my motor, even with 235,000 miles that 6 (!) other owners put on it. Seriously. That's how much faith I have in the LS, in general, and my engine, in particular. And if I blow it up, you *know* I'll come back here and say "you were right". But I won't blow it up. Even if I did -- with the mileage / history that it has, I wouldn't fault the motor, at all. Just the operator :wink:
 
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mrrsm

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Fair Enough... and if your were speaking strictly about basically Turbo-Charging your Stock LS Motor for Natural Oxygen and Pump Gas ...NP. But Nitrous Oxide is a Whole 'Nother Animal.

FWIW... Check out the adjustments this Engine Builder follows after taking Two LS Motors that fell to 'the vagaries' of Nitrous Oxide Boosting (Broken Stock Connecting Rod and Melted, Seized Stock Piston).

If God Forbid... anything becomes problematic and you decided to do more work on the Short Block... This VOP's Tips on Building the LS Motor for Nitrous are worth saving:

Part 1:


Part 2:


"...And Now for Something Completely Different"


I appreciate you not 'Bristling' too much ...and I would never imagine you doing anything 'petty' in response to a Fellow Member who likewise approaches Engine Building with such an Abundance of Caution over situations this challenging ...and so they magnify and focus my concerns.
 
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