Superduty

"Could this recommendation come from the fact that most fuel injection systems operate in the 35-60 psi range?"

Yep.

"The blue won't make that much pressure and thus would be a poor fit for that application. It's made for carbs that need 7-12 psi of inlet pressure. That designed application doesn't mean it's junk."

Except that the whole pump is designed around the delivery pressure. It has a lighter motor, windings, heat rejection, brushes, etc.

Comparing a carburetor pump to a fuel injection pump is like comparing a 1/2 ton gasser to a 3/4 ton diesel for the purposes of hauling 1500 pounds. The gasser will do the job but it won't last doing it all the time. The 3/4 ton diesel will.

Here is another way to look at it: At 20 PSI, the Holley and the Walbro will both output about the same volume of fuel. The Holley is operating at 150% of its maximum rating. (21 PSI/14PSI = 150%). The Walbro is operating at 20% of its maximum rating. (20PSI/100PSI) Which do you think will last longer ?

I don't mean to hammer you on this. I didn't think the comparison was going to be this stark. I just want to get this stuff into a discussion so people start thinking about it. No hard feelings and if the Holley works good for you, great.

banshee

Hammering me? Hardly. My setup is completely differenent than just a holley anyway.

You said yourself you don't need high pressure, so why compare at 20psi? You said yours is set at 5, so why not compare there?

You say the holley is built like a 1/2 ton gasser, and it may be compared to the fass, walbro, etc, but IMO that helps its longevity. Big pumps pull big amps which make big heat. Heat kills an electric motor... no brainer there. The holley blue pulls a mere 3 amps and they get only warm after hours of running.

What's the advantage in overpumping the system?

Barry St John

Kudo's to Superduty for the good info. I'll probably keep my stock pump mounted back by the tank and watch the pressure guage because the hookup is so easy and I believe that the main problem with the stock lift pumps is solved when they are used as pushers. All of the pump solutions seem to have their share of problems with the ultimate solution being a new cam and a mechanical pump. "The cam is for more efficient power and you might as well use the pump when you have the lobe!"

ratsun

OK not trying to start anything but...
First: I have owned a 3 stock LPs/many holley + carter pushers/ and a FASS system.
I have never owned the Walbro pump you speak of so I cant comment or doubt its abillity however the FASS system is a first class system. Have you ever owned and installed one? Yes they are expensive and generally allot more than most of us need to supply our current power demands but if you want rid yourself of the cheesy stock LP and filter on the truck to a nicer set-up whats the big deal? For me the eaze of filter change was almost worth-it so I didnt have to scrape up my forarm reaching down to change the stock filter. Would I pay $350 for a FASS transfer pump? No, but I did pay $ 600 for the compleate kit that totally eliminated the stock fuel supply system tank to IP. As far as the FASS ability to save your IP well....? some things just cant be saved. Yes you are correct in saying you can deliver enough fuel for less money but its all in what you want. I have read people are doing cam swaps to get the mechanical pumps on, to get away from the stock LPs thats well over a grand?

Superduty

"Hammering me? Hardly. My setup is completely differenent than just a holley anyway."

I'm glad I didn't offend you. I just want to intiate a discussion.

"You said yourself you don't need high pressure, so why compare at 20psi? You said yours is set at 5, so why not compare there?"

Good question. Mine does run at 5 PSI. With a clean filter. With warm fuel. Supplying a CP3 that needs no pressurized supply. What happens if my filter gets dirty and it takes 15 or 20 PSI to push the fuel through ? With a Holley I am operating outside of the design of the pump. Too much of that and we have another failed pump. Or we start starving the CP3. Or both because the pump performance degrades as the brushes wear out. And then we continually starve the CP3.

With the Walbro I get away with it.

With a VP44 we probably always want to supply it at 15 PSI, so I'm not sure I would be comfortable with the Holley.

"You say the holley is built like a 1/2 ton gasser, and it may be compared to the fass, walbro, etc, but IMO that helps its longevity. Big pumps pull big amps which make big heat. Heat kills an electric motor... no brainer there. The holley blue pulls a mere 3 amps and they get only warm after hours of running."

OK... a couple things here.

The Walbro is as efficient or more efficient than the Holley. So for the same load they will pull roughly the same current.

Now... when your Holley pulls 3A it is operating at 100% load. When the Walbro pulls 3A, it is operating at 25% load. The Walbro is designed with larger brushes, better heat dispation, etc, so it can handle more load.

Then there is the issue of cooling. The Holley is a totally enclosed fanless air cooled pump. What that means is that the armature and brushes run in an enclosed can from which no air/moisture/etc. can enter or leave. There is no external fan. (In contrast to Totally Enclosed Fan Cooled AC motors or TEFCs) In the Holley the temperature of the brushes and armature can be quite a bit warmer than the case itself because of the insulation effect of the can.

The Walbro and the Bosch and other inline flow through pumps are cooled by the fuel they pump. The armature and brushes are continually bathed in fuel. This does a number of things. It keeps everything cool, at the same temperature as the fuel anyway. It lubricates the brushes. It washes away all the carbon that the brushes burn. The inline fuel cooled pumps end up lasting a lot longer.

"What's the advantage in overpumping the system?"

The Walbro doesn't overpump anything if the same pressure relief system is used on both pumps. If the Walbro and another pump are both pushing the same volume of fuel and both pumps are running with the same hopefully clean fuel filter and pressure relief system, then both pumps will have the same pressure.

But I'll throw this back at you. Why are these pumps so huge flow wise ? A stock 325/600 needs 25 GPH to the CP3. Why are people saying they need pumps with 80,90, 150 GPH ??? I'd much rather have a pump that did 40 or 50 GPH and could do it to 30 PSI than a high flow pump that maxes out at 15 or 20 PSI. The lack of flow at WOT isn't because the pumps need more GPH. It is because they need more PRESSURE.

When people are replacing stock 3/8" lines with 1/2" lines they are doing the wrong thing. They need to replace the pump, not the lines.

Here is another way to look at it. Lets say our monster diesel engine needs 60 GPH. The Walbro will supply that at back pressures of 50 PSI. You can move a ton of fuel through a 3/8" line with 50 PSI.

Superduty

"OK not trying to start anything but..."

It is a discussion. All points are welcome.

"however the FASS system is a first class system. Have you ever owned and installed one?"

Sure it is. The parts are nicely machined. It has a built in pressure regulator.

"Yes they are expensive and generally allot more than most of us need to supply our current power demands but if you want rid yourself of the cheesy stock LP and filter on the truck to a nicer set-up whats the big deal?"

Nothing. Each to his own liking. I applaud you for doing something about your fuel supply problem.

"For me the eaze of filter change was almost worth-it so I didnt have to scrape up my forarm reaching down to change the stock filter."

We all have our own preferences.

"Would I pay $350 for a FASS transfer pump? No, but I did pay $ 600 for the compleate kit that totally eliminated the stock fuel supply system tank to IP. As far as the FASS ability to save your IP well....? some things just cant be saved."

I don't know about that. Is there a single Dodge truck in the world that has always had a good, clean uninterrupted supply of fuel ? Until that happens we will never know.

The CP3 on my Ford was fed by the Walbro since it was fired up for the first time. Time will tell how long it lasts. I'll keep you informed.

"Yes you are correct in saying you can deliver enough fuel for less money but its all in what you want. I have read people are doing cam swaps to get the mechanical pumps on, to get away from the stock LPs thats well over a grand?"

I agree. The only reason I named FASS like I did was to initiate discuss and thought. I've got no goal here other than to make people aware that options exist.

banshee

First of all, a fuel pressure gauge will detect falling pressure and thus a restriction/dirty filter or a failing pump. The first line of defense when you get low supply pressure is to change the filter and try the pressure again. 99% of the time that is the problem. Using a massive pump to push through an old, plugged filter is a no-no. Also, I'm not sure how you're getting to the point that the blue is rated to run at only 7psi? That webpage shows it's rated to flow 95 gph at 7psi, and it also goes on to say that it flows 88gph at 9 psi. It's just a rated flow... put them all together and you get a pump curve. These pumps come with a 14 psi internal regulator, so they are safe at 14 psi. They will provide 12-13 psi through a clean filter on a stock 305hp truck. Even with a draw of 500 hp they will only sag to 5-6 psi, so they are not maxed out IMO.

Not according to your pump/current curves. It looks more like 6 amps (roughly)

Those ratings are free flows, not at pressure. I'm sure the fass flows more than a holley, but it's probably more around the area you are wanting, and it's got enough pump oomph to make that much pressure. Heck, ATS is using one in their CP3 mod, and it's making 120+ psi. See my statements on the pressures on a 500+ hp truck. If 5 psi is enough, and you have a gauge to monitor, then why the massive pump? FWIW I run 26 at idle and 18 at WOT making the power in my signature. I run two pumps though... think of it as twin turbos for the fuel system

Again, I think it's wrong to use a massive pump to overcome restricion when you can eliminate the restriction and use less. It's more efficient that way and should be more reliable. Banjo bolts aren't designed to flow 50 or 60 gph. They're great for brakes where a column of fluid moves 1/4", but if you're flowing a fluid an elbow works MUCH better. I run 3/8" lines in my setup, but my banjos went out the window a long time ago. This has been proven to be worth 4-5 psi of restriction at high flow rates.

I have no beef with any of the pumps... I'm just discussing.

Superduty

"Some diesel fuel tends to be dirtier than others ,depending on stations used . It's the dirt that will destroy the pump .Hence the reason why they don't last long . Now if you were to put a 20 micron screen in front or the pump before it gets fuel , then it would be ideal."

I think that is a good suggestion.

Here is another thing. The Bosch lift pumps used in the Ford SD trucks (99+) has proved to be very reliable. There is no pre pump filter. One issue with pre pump filters is restriction on the suction side of the pump, especially when the fuel is cold.

I handled this issue by circulating ALL the fuel that gets pumped through the main filter before it gets returned to the tank. If any dirt gets into the tank it gets captured in the filter the first time it is pumped. My tank gets cleaned as I run the fuel pump. If the fuel return is before the filter then the dirt just keeps circulating in the system, wearing the pump out.

"And yes the Carters and Holley pumps are air cooled, but that's not what destroys these pumps either . See the fuel lubes the impellors on these pumps and again dirt plays the demon on these."

The motors do fail on these. The brushes wear out at high currents, like they will for all DC motors. Dirt will wear out impellers, but impellers are designed for low pressures. The gerotor pump is a better design which is why they are sometimes used in engine oil pumps.

"Another thing that kills the LP is vibration and the LP is hard mounted . The Cummins and other diesels not only vibrate but give a frequency and this I believe is the single most problem the pump has ."

Can't argue with that. Mount the lift pump on the frame or in the tank. The Walbro (and the Ford Bosch) are mounted in a rubber lined cradle. It quiets them too because their vibration is isolated from the frame.

The pumps cooled by fuel can be mounted in a rubber enclosure because they are cooled by the fuel. The air cooled pumps shouldn't be covered up because they need airflow.

Superduty

"First of all, a fuel pressure gauge will detect falling pressure and thus a restriction/dirty filter or a failing pump."

Sure it will. Do we all run one or watch it ? Nope.

"The first line of defense when you get low supply pressure is to change the filter and try the pressure again. 99% of the time that is the problem."

Err... not really. There are lots of posts around with "my fuel pressure drops to 0 PSI at WOT". Look in 3rd gen Aftermarket.

"Using a massive pump to push through an old, plugged filter is a no-no."

Yep. So is starving your injection pump. Which one costs you more money ?

"Also, I'm not sure how you're getting to the point that the blue is rated to run at only 7psi?"

Here: www.holley.com/types.asp?type=76 . It says. Flow@ rated pressure. 95 GPH at 7 PSI. That is the pressure that pump was designed to run at continuously.

"That webpage shows it's rated to flow 95 gph at 7psi,"

Specifically, is says "GPH Flow (at) Rated PSI" Same wording, minus the "at" in both tables.

"and it also goes on to say that it flows 88gph at 9 psi. It's just a rated flow... put them all together and you get a pump curve."

Yes, but the design rating was 7 PSI. The pump will operate anywhere along the curve. But its pressure rating is 7 PSI. Its maximum pressure is 14 PSI. It will do more, but you aren't supposed to run it there.

"These pumps come with a 14 psi internal regulator, so they are safe at 14 psi. They will provide 12-13 psi through a clean filter on a stock 305hp truck. Even with a draw of 500 hp they will only sag to 5-6 psi, so they are not maxed out IMO."

Sure they will run at 14 PSI. The life will be shortened considerably. The pump was designed to run at 7 PSI as its baseline.

Lets say you do run at 14 PSI and it drops to 5 PSI. Now add a dirty filter. Or let the pump wear a bit. What do you have ? There is no safety margin in those numbers.

Furthermore, why is the pressure dropping to 5-6 PSI supplying the 500 HP engine ??? This is where the alarm bells go off. 500 HP is 40GPH. That pump is supposed to put out 88 GPH. Why is the pressure falling ? The relief is still set at 14 PSI, right ? What you just experienced was a worn pump. The regulator shuts off at 14 PSI and now the pump has all it can do to supply the 500 HP engine its 40 GPH.

One day the filter gets dirty, the driver goes to WOT the pump starves a bit and two months later he is looking for a CP3 or VP44. Or posting to the forum that his truck doesn't start or run properly. (Hasn't figured out the injection pump is damaged.)

One more thing while we are at it. The Holley has a built in regulator. This means that the fuel it pumps gets returned to the tank before it gets filtered. This means that dirt will circulate through the pump again and again and again without being removed. Ideally the regulator would be located downstream of the filter.

"The Walbro is as efficient or more efficient than the Holley. So for the same load they will pull roughly the same current.

Not according to your pump/current curves. It looks more like 6 amps (roughly)"

At 6 Amps the Walbro is putting out 75+ GPH at 25 PSI. The Holley is stalled. It will burn out. I don't see a current curve for the Holley. The 3 Amps they quote is a nominal current, probably for 7 PSI. The actual amount of current it draws depends on the load, just like any other DC motor.

"Those ratings are free flows, not at pressure. I'm sure the fass flows more than a holley, but it's probably more around the area you are wanting, and it's got enough pump oomph to make that much pressure."

I totally agree with this. I'm surprised that nobody has a pump curve for the FASS.

"Heck, ATS is using one in their CP3 mod, and it's making 120+ psi."

????

"See my statements on the pressures on a 500+ hp truck. If 5 psi is enough, and you have a gauge to monitor, then why the massive pump?"

The Walbro isn't a massive pump. It is about 2" in diameter and 5" long. The fuel cooled pumps are smaller than the air cooled pumps because they don't need to worry about the heat. The Bosch is a bit larger.

You are right the Walbro is way over kill pressure wise and flow wise for the application. You guys would have laughed at me silly if I recommended a smaller pump, but really one of the smaller/lower pressure Walbros would do easily.

"FWIW I run 26 at idle and 18 at WOT making the power in my signature. I run two pumps though... think of it as twin turbos for the fuel system"

It would be totally unnecessary to run two pumps if you ran one Walbro. Look at the curve. It says it all.

"Again, I think it's wrong to use a massive pump to overcome restricion when you can eliminate the restriction and use less."

Do you water your lawn with 3/4" hose at 50 PSI or did you use a 2 inch hose and 10 PSI ?

You have to replace the lift pump anyway. Are you going to buy a 15 PSI pump and replumb your truck or buy a 50 PSI pump that is built better and leave the plumbing alone.

"It's more efficient that way and should be more reliable."

More efficient ? Yes, the pump will draw 1 amp less. More reliable ? Sure, because the pump operates at a slightly lower current. Worthwhile ? No.

"Banjo bolts aren't designed to flow 50 or 60 gph. They're great for brakes where a column of fluid moves 1/4", but if you're flowing a fluid an elbow works MUCH better. I run 3/8" lines in my setup, but my banjos went out the window a long time ago. This has been proven to be worth 4-5 psi of restriction at high flow rates."

And the Walbro will push 60, 80 PSI if you need it to. Why dick around removing banjo bolts to save a few PSI ? This is nothing but compensating for a low pressure pump.

"I have no beef with any of the pumps... I'm just discussing."

And it is a good discussion. Thanks.

Superduty

"These pumps come with a 14 psi internal regulator, so they are safe at 14 psi. They will provide 12-13 psi through a clean filter on a stock 305hp truck. Even with a draw of 500 hp they will only sag to 5-6 psi, so they are not maxed out IMO."

Here is the deal with this. You are measuring fuel pressure at the CP3. That is good.

The regulator is built into the Holley pump. It is set for 14 PSI. THERE IS A FUEL FILTER AND FITTINGS BETWEEN THE HOLLEY AND THE CP3. (Just emphasis, not yelling...)

At idle when the fuel flow to the pump is low, the pressure is the same at the CP3 as at the Holley. However, at WOT the fuel flow through the filter and fittings is high and there is lots of pressure drop and you no longer see 14 PSI. You see 5 or 6 PSI.

You can add more Holley pumps to your system until you are blue in the face and it ain't going to get your CP3 pressure up. The fuel pressure at the Holley(s) will still be 14 PSI. The fuel flow to the CP3 will still be what it is and the pressure drop across the filter and fittings will still be the same. You will still have 5-6 PSI to the CP3. The only thing you did by adding more Holleys was increase the return flow to the tank. (Should we start discussing efficiency now...)

The way to fix this problem is this. Plug off the regulators on the Holley(s). Or set them at 50 PSI. Put a bypass line on the CP3 like the one in my pictures, but put a regulator in it. Now you will get 14 PSI at the CP3 when the engine is idling AND at WOT, **IF** the fuel pump can keep up.

I say if because if you have 14 PSI at the CP3 and you have 8 PSI drop across the filter and fittings like you did before, you now need 22 PSI from the Holley to keep the pressure at the CP3 at 14 PSI. However, the Holley won't make this pressure, so, once again your pressure drops.

You need a higher pressure pump. And you should replumb your system so that the pressure regulator is at the CP3 bypass and so that all the pumped fuel gets filtered.

banshee

Let me get this straight... you're saying that if you add two pumps in series you get NO increase in pressure? I hope not, because that's an error. I run two pumps not rated at more than 14 psi, but I manage to see 26 psi at the cp3 inlet. Pressures DO add when running two pumps, but flows will not. It's kind of like putting two batteries in series... you get double the voltage at the same amperage. Adding another pump would just send the running pressure even higher... it would not just return more fuel to the tank.

You are a little off on your restriction estimates. A stock truck will not drop to 5 or 6 psi running a holley. Try it. Hell, a 450 rwhp truck won't drop that low. By looking at that walbro pump curve I don't think it'll measure up for a 600 hp truck. I also disagree with your 7psi assumption for the holley's designed running pressure. Without arguing more I guess we'll just have to leave it at that. For now the wimpy little Holley is doing just fine feeding 600hp

big red psd cc

Some good reading!!!

I am running 17psi monitored at the CP3 inlet.

Holley Blue with the extra regulator along the frame back at the tank, running into the stock LP for now. The pressure never drops belows 12-14 at WOT.

I look at it this way, the stock lift pumps die mostly because they are "pulling" rather than "pushing". So if I can keep it fed by the Holley (lets say 9psi), the LP has plenty of fuel, and then it up's the pressures another 6-7 psi. The Holley is in spec, the stock LP is getting fuel, and the CP3 is getting fuel.

As for the LP going south, so can a FASS, Walbro, etc, they all can. But if you can keep the stock LP with fuel and make its life, it will last longer.

I used to run the system at 15max psi, then upped it some.

The other question here is........how high of a pressure can be fed into the CP3 before it says "Adios" and you start to get leaks???

Superduty

"Let me get this straight... you're saying that if you add two pumps in series you get NO increase in pressure? I hope not, because that's an error. I run two pumps not rated at more than 14 psi, but I manage to see 26 psi at the cp3 inlet. Pressures DO add when running two pumps, but flows will not. It's kind of like putting two batteries in series... you get double the voltage at the same amperage. Adding another pump would just send the running pressure even higher... it would not just return more fuel to the tank."

I thought you were running them in parallel. I thought the relief valves were set to for 14 PSI max ?

You really need to look at a Walbro.


=================================================
Quote:
Originally Posted by Superduty
The way to fix this problem is this. Plug off the regulators on the Holley(s). Or set them at 50 PSI. Put a bypass line on the CP3 like the one in my pictures, but put a regulator in it. Now you will get 14 PSI at the CP3 when the engine is idling AND at WOT, **IF** the fuel pump can keep up.
I say if because if you have 14 PSI at the CP3 and you have 8 PSI drop across the filter and fittings like you did before, you now need 22 PSI from the Holley to keep the pressure at the CP3 at 14 PSI. However, the Holley won't make this pressure, so, once again your pressure drops.
You need a higher pressure pump. And you should replumb your system so that the pressure regulator is at the CP3 bypass and so that all the pumped fuel gets filtered.
================================================== ==

"You are a little off on your restriction estimates. A stock truck will not drop to 5 or 6 psi running a holley. Try it. Hell, a 450 rwhp truck won't drop that low."

I am going by the numbers you gave in your post. I was just quoting what you gave and working with it. Whatever fuel pump it was.


"By looking at that walbro pump curve I don't think it'll measure up for a 600 hp truck."


Well... exactly how much flow does a 600 HP truck need ? And don't tell me you run a 100 GPH pump and it doesn't feed it. Because the 100 GPH pumps aren't putting out 100 GPH and that is the problem.

You are running 2 Holleys at 14 PSI each right ? At 14 PSI, the Holleys put out about 80 GPH according to the flow curve in the chart. And the Walbro puts out 75 GPH. So, if your two Holleys can feed the engine, so can the Walbro. Now, lets note something else here. Your Holleys are working at 100% of their maximum pressure and 200% of their rated pressure. The Walbro is running at less than 50% of its rated pressure.


"I also disagree with your 7psi assumption for the holley's designed running pressure. Without arguing more I guess we'll just have to leave it at that. For now the wimpy little Holley is doing just fine feeding 600hp"

2 Holleys, right ?

BTW: this page says the fuel regulator is 14 PSI max. How are you getting 28 PSI from the second Holley ? The pressure capability of the pumps will add, but the regulator in the second pump will limit the pressure to 14 PSI. The second pump doesn't buy you anything pressure wise. What am I missing ?

big red psd cc

The Holley Blue come with an external regulator that is adjustable. If you don't use the regulator, it will just run "WOT", until the factory regulation limits the total system pressure.

If his system does not have the regulator(s) installed, it would 14+14=28 psi total pressure.

ratsun

[QUOTE=Superduty
When people are replacing stock 3/8" lines with 1/2" lines they are doing the wrong thing. They need to replace the pump, not the lines.

Here is another way to look at it. Lets say our monster diesel engine needs 60 GPH. The Walbro will supply that at back pressures of 50 PSI. You can move a ton of fuel through a 3/8" line with 50 PSI.[/QUOTE]
__________________________________________________ _

Superduty
I agree with what your saying on the volume vs psi thing but want to piont out the 2nd gens had no where near a 3/8" delivery. The holes in the 5 banjos are tiny ( I cant remember off hand the exact size 1/8"?) so when the fuel delivery issue reared its head the fix was more in the restrictive fittings than the line. It was tough to come up with anything to addapt to the factory lines other than drilling out the banjos which made them weak so a line change was eazier. I dont know what size the third gens have for fuel lines but on my second gens the steel line fits inside 3/8 rubber fuel line.