fuel system questions

[psduser1]

Ok guys I've got a couple of questions.
I've read pages and pages of other peoples setups, and talked to some different vendors, etc. Overwhelming opinion is that a rr through the heads is the "best" setup for consistent, reliable performance.
Having said that, there seems to be a lot of different thoughts on pumps and fuel cooling. Some guys like one big pump (read Fuelab), some guys like a couple of Airtexs, still other guys have a bigger and a smaller pump in series, Cummins style.
Personally, I like two pumps in parallel for simplicity's sake.

My question is where can I find flow info on a stock fuel pump- airtex, carter, bosch, no name, whatever. Any thoughts in reliability, noise, performance. Fwiw, the airtex, carter etc. pumps run approximately $175-200, the Bosch (oe replacements ) run roughly double, comparble(?) to a Fuelab. I have looked at the Fl and understand what they are selling, I just don't like the pricetag for a dual system setup, which is what I'm after. Thoughts?

The second half of my question is fuel cooling on the return to the tank. I am convinced there are benefits, however I would like to be able to be able to have some at least rough calculatios to prove or disprove this. Also how much cooler is needed to maintain effective cooling on say, 85 degree days, for a starting point. There is a wide range of coolers out there, from $29 jegs to $500 plate and fin hydraulic coolers. I'm guessing that I'm going to be at the lower end of that range, but I have no supporting evidence.
Any thoughts on these questions would be appreciated, and big thanks to Tarm and Treetrimmer for their writeups, they are a big help for us less knowledgeable guys!
I'm looking to support max roughly 500-550 HP, towing heavy at closer to 300-350 HP range, often long distances.

 

[Biggreen96]

As far as pumps go i found walbro 392 pumps on ebay for 100 each and am getting ready to install my system. I do know the walbro pumps flow enough fuel with one pump for my injectors but am going to do the same as you and run two.

 

[psduser1]

Walbro is an option, however I seem to get mixed reaction on this specific brand. I tend to believe that you get what you pay for, generally, and durability is pretty high on my list. Not at all interested in fixing stuff 1200 miles from the house, if i can help it!
Thanks for the input, and if some other people care to detail their experience with specific pumps, I'm all ears.
I'm also looking for hard numbers if I get/find them.:thumbsup:

 

[farm boy]

My fuelab has been going strong 1.5+ years. I like it. I run a cooler on the return line. I dont have any hard data on it helping or hurting, but when I touch my filters under the truck after driving, they seem cooler. Cant hurt. I think I bought it off ebay for cheap.

Only thing that sucks is I'm only running one pump, so if it ever goes out, I'm stranded. I might pick me up a spare cheap pump to keep in the tool box one of these days that can be swapped in place on the side of the road.

 

[Tom S]

Catdiezel??? has in the past posted up some really good info on fuel temps on the old site. He also posted up the temp at which the overtemp fuel light came on in the semis with HUEI injectors. I can probably find that again with a little work.

 

[psduser1]

Thanks Tom, if you don't mind. I'll look around somemore also, but I'm limited on posting links etc. mostly cause I'm not very good with my phone.

 

[Strictly Diesel]

Having said that, there seems to be a lot of different thoughts on pumps and fuel cooling. Some guys like one big pump (read Fuelab), some guys like a couple of Airtexs, still other guys have a bigger and a smaller pump in series, Cummins style.
Personally, I like two pumps in parallel for simplicity's sake.

I tell my customers that the answer here depends on what they are doing with the truck. The factory Bosch pumps are extremely reliable and have been known to run well over 200k miles. That's tough to beat. They problem with them is that they don't flow enough for bigger power setups. I've tried a number of pumps and as much as I've fought it due to the cost, I keep coming back to needing to build a dual stock Bosch fuel pump setup for my customers that need big power fuel flow with factory reliability.

I love the Fuelab pumps we sell, and I recommend them all the time for guys who are working on a "toy". If your truck doensn't get driven daily, if you don't need to count on it for a long family road trip or in day to day bumper to bumper driving, they are a great pump. They are the most reliable aftermarket pump I've tested, hands down. That said, I can't tell you they will last 100k miles and I can't tell you that if you do break down in the middle of nowhere, it will be easy to find a bolt in replacement. If you are running a stock pump, you can get another stock pump (or even a parts store chinese copy of a stock pump) to directly replace it and get you moving in pretty short order.

For me, the decision comes down to whether you want OEM level reliability or "race parts" reliability. ANY of the aftermarket pumps (Fuelab, Aeromotive, SX, etc) will be this way...they are much closer to being "race car parts" than they are to being OEM parts...so they will have "race car parts" reliability. Some people might get 100k miles out of one of those pumps, but I wouldn't stake my reputation on it and I certainly wouldn't tell a customer to expect it. With the stock Bosch pumps, if they are not starved for fuel or run at extremely high pressures, they will very likely give you OEM level reliability for 100k+ miles.

For what it's worth, the Walbro pumps and the Bosch 044 pump that are commonly recommended are NOT rated for diesel fuel, are NOT covered under any warranty if used with diesel fuel...and therefore are not recommended (at least by me and their respective manufacturers) for use with diesel fuel. I've checked with Walbro on this same question several times, they don't have a diesel rated pump. Bosch is harder to check with, but they have specifically told me that the stock pump they produce for Ford is the only one they recommend for diesel fuel use. They DO NOT have any pumps that are rated for diesel fuel and have a higher flow rating. Take that for what it's worth, I personally won't sell a pump to a customer if the manufacturer won't stand behind it...I can't do that to my customers (which is why I stopped selling another product that has not been discussed yet in this thread).

My question is where can I find flow info on a stock fuel pump- airtex, carter, bosch, no name, whatever. Any thoughts in reliability, noise, performance. Fwiw, the airtex, carter etc. pumps run approximately $175-200, the Bosch (oe replacements ) run roughly double, comparble(?) to a Fuelab. I have looked at the Fl and understand what they are selling, I just don't like the pricetag for a dual system setup, which is what I'm after. Thoughts?

My only thoughts here are as follows...

The Fuelab pump we sell flows about double the stock pump (at the low speed setting on the Fuelab). That was very intentional, we worked with Fuelab to specify that particular speed to get the flow where we wanted. At the reduced speed, the pump is relatively quiet, amp draw is reduced and it moves about 65-70gph at about 65psi.

2 stock pumps will be moving about that same amount of fuel at the same pressure. The difference, 2 stock pumps will be more reliable. Both of them are likely to run 100k miles plus, and if you do lose one pump...you've at least got the second one to get you off the road or even home if you turn the power down to where there is no pressure drop on one pump.

The second half of my question is fuel cooling on the return to the tank. I am convinced there are benefits, however I would like to be able to be able to have some at least rough calculatios to prove or disprove this. Also how much cooler is needed to maintain effective cooling on say, 85 degree days, for a starting point. There is a wide range of coolers out there, from $29 jegs to $500 plate and fin hydraulic coolers. I'm guessing that I'm going to be at the lower end of that range, but I have no supporting evidence.

I tested the cooler thing several years ago and found no significant evidence that it did a darn thing for these trucks. The fuel returning to the tank didn't lose significantly more heat through the cooler, and even running from full to empty without stopping and filling up and without a fuel cooler didn't produce any significant increase in fuel temperatures in the tank. I just looked and the articles I wrote about it are not published on my site anymore...I guess I need to figure out where those went, looks like they were lost in an upgrade.

Hope that helps.

 

[Tom S]

I posted what the optimal temp is above....Cat knows best LOLoke: atleast on how to test one that is.

There is indeed some science behind 60* F

I agree the pump and filters get pretty warm during a long haul like when you have exhausted a tank of fuel in the summer time. Seems like 140 was a number I recorded last summer under those conditions.

http://www.thedieselstop.com/forums/f25/fuel-cooler-test-results-77398/

http://www.thedieselstop.com/forums/f25/reg-return-fuel-cooler-installation-results-67861/

http://www.thedieselstop.com/forums/f25/fuel-cooler-why-who-needs-one-106087/

http://www.thedieselstop.com/forums/f25/fuel-cooler-34690/

That was the information from Justin I was looking for.


Tom

There is a start

 

[Tom S]

150 degrees was the temperature that tripped the light and set a code.

 

[genie144]

Tom - what sensor is that? Fuel temp...

Sam

 

[psduser1]

Thanks Tom ill check those links ASAP, on the clock right now.
One hundred fifty degrees is a long way from 60-65 deg. That can't be good!
Dennis I found your old posts, can't remember where now. That's what prompted my questions! I guess I was wondering if you still held the same position, or something had changed your mind since those posts.
As for pumps, for oem reliabity, buy oem. Bosch to be precise.My stock pump seems to be going strong at 175xxx miles. I guess I'm just looking for a less expensive option, or at least a different one.

 

[Tom S]

Yes, I need to do some more digging.

 

[pjwoolw]

I tell my customers that the answer here depends on what they are doing with the truck. The factory Bosch pumps are extremely reliable and have been known to run well over 200k miles. That's tough to beat. They problem with them is that they don't flow enough for bigger power setups. I've tried a number of pumps and as much as I've fought it due to the cost, I keep coming back to needing to build a dual stock Bosch fuel pump setup for my customers that need big power fuel flow with factory reliability.

I love the Fuelab pumps we sell, and I recommend them all the time for guys who are working on a "toy". If your truck doensn't get driven daily, if you don't need to count on it for a long family road trip or in day to day bumper to bumper driving, they are a great pump. They are the most reliable aftermarket pump I've tested, hands down. That said, I can't tell you they will last 100k miles and I can't tell you that if you do break down in the middle of nowhere, it will be easy to find a bolt in replacement. If you are running a stock pump, you can get another stock pump (or even a parts store chinese copy of a stock pump) to directly replace it and get you moving in pretty short order.

For me, the decision comes down to whether you want OEM level reliability or "race parts" reliability. ANY of the aftermarket pumps (Fuelab, Aeromotive, SX, etc) will be this way...they are much closer to being "race car parts" than they are to being OEM parts...so they will have "race car parts" reliability. Some people might get 100k miles out of one of those pumps, but I wouldn't stake my reputation on it and I certainly wouldn't tell a customer to expect it. With the stock Bosch pumps, if they are not starved for fuel or run at extremely high pressures, they will very likely give you OEM level reliability for 100k+ miles.

For what it's worth, the Walbro pumps and the Bosch 044 pump that are commonly recommended are NOT rated for diesel fuel, are NOT covered under any warranty if used with diesel fuel...and therefore are not recommended (at least by me and their respective manufacturers) for use with diesel fuel. I've checked with Walbro on this same question several times, they don't have a diesel rated pump. Bosch is harder to check with, but they have specifically told me that the stock pump they produce for Ford is the only one they recommend for diesel fuel use. They DO NOT have any pumps that are rated for diesel fuel and have a higher flow rating. Take that for what it's worth, I personally won't sell a pump to a customer if the manufacturer won't stand behind it...I can't do that to my customers (which is why I stopped selling another product that has not been discussed yet in this thread).


My only thoughts here are as follows...

The Fuelab pump we sell flows about double the stock pump (at the low speed setting on the Fuelab). That was very intentional, we worked with Fuelab to specify that particular speed to get the flow where we wanted. At the reduced speed, the pump is relatively quiet, amp draw is reduced and it moves about 65-70gph at about 65psi.

2 stock pumps will be moving about that same amount of fuel at the same pressure. The difference, 2 stock pumps will be more reliable. Both of them are likely to run 100k miles plus, and if you do lose one pump...you've at least got the second one to get you off the road or even home if you turn the power down to where there is no pressure drop on one pump.


I tested the cooler thing several years ago and found no significant evidence that it did a darn thing for these trucks. The fuel returning to the tank didn't lose significantly more heat through the cooler, and even running from full to empty without stopping and filling up and without a fuel cooler didn't produce any significant increase in fuel temperatures in the tank. I just looked and the articles I wrote about it are not published on my site anymore...I guess I need to figure out where those went, looks like they were lost in an upgrade.

Hope that helps.

Good info Dennis! Thanks!

 

[Strictly Diesel]

Thanks Tom ill check those links ASAP, on the clock right now.
One hundred fifty degrees is a long way from 60-65 deg. That can't be good!
Dennis I found your old posts, can't remember where now. That's what prompted my questions! I guess I was wondering if you still held the same position, or something had changed your mind since those posts.

No change in my position. If you look at the fuel routing and consider that in order to get to the injectors, the fuel has to pass through a cast iron cylinder head (where the fuel rail is machined) which is at least the same as the engine coolant temp (likely significantly hotter), you are left with little conclusion other than the fact that just like the coolant, the fuel will remove heat from the head as it passes over it...making the fuel hotter as it moves through the system. In a return type setup, as the fuel leaves the head and goes back to the tank, the opposite happens. We found a pretty significant temperature drop between the head and the fuel tank just from the fuel passing through a metal fuel line that was cooler than the fuel.

I understand the concept, but we have installed a bunch of fuel systems and driven them here in 115 degree+ weather with no ill effects and no apparent difference in how the truck ran (mpg, power, etc). My own trucks have been driven well in excess of 100k miles with these fuel systems and I've got a TON of customers with the same setup, if there was an issue, it would be apparent by now.

FWIW, it does make sense to use a cooler on a Duramax (or other Common Rail diesel) due to the extremely high pressures the fuel is brought to...that will introduce some heat. I would say that in our application, 99% of the temperature increase through the system is from taking heat away from the heads, not from the fuel pump making pressure.

As for pumps, for oem reliabity, buy oem. Bosch to be precise.My stock pump seems to be going strong at 175xxx miles. I guess I'm just looking for a less expensive option, or at least a different one.

If your pump has lasted almost 200k miles, and it costs you $400 to replace it, why look for something less expensive. Most of these trucks are 10 years old now...so not only did your pump got a lot of miles, it lasted a long time as well. I would challenge any aftermarket pump to do that as repeatably as the stock Bosch pump...and I would bet that there isn't one out there that will.

 

[TARM]

you might want to also look at another Bosch pump. They are basically up sized version of our stocker and flow about what the larger fuelab does on reduced setting or 280-300lph or 70-80gph. Flow rate of Walbro 392 @ 65-75psi is around 55gph+/-

I recommend people take a look at the Bosch 044 pump as well.

It also has larger inlet/outlet compared to stocker or the walbro and its inlet is larger than its outlet which is proper sizing ratio. Is only slightly louder than stock pump.

I would still recommend if you want to longest life possible for any of these pumps that a lift pump be used unless you are running a sump outlet from the tank.


I will be running a number of extensive fuel temp tests in the near future with and without the cooler inline. Its using a V10 trans cooler as the fuel cooler. Look up my fuel system here:

Fuel System with a different twist installed

While the title is fitting for what I did that pump has proven to be super reliable as a stand alone as well and is one of the most popular one used for ricers. I looking for top quailty. I will be doing as many detailed tests as possible on fuel. Will try to get some dyno time in as part of it as well. But one of the largest effects we should care about beyond effects on power is lubricity and viscosity. That is what protect our injector's barrels and plungers from wear and scaring. The hotter the fuel gets the thinner and weaker the protective film. This in turn can lead to a decreased life and accelerated wear. The HEUI is very unique in its effect on fuel temps with its internal fuel rails and then the use of a flow thru return fuel system. I am trying to dig up some charts that woudl show the effects by temp on the lubrication specs of diesel. If I can not I may send off a sample or see if one of the lubricant labs can give me the numbers. The other thing that just a fact of science is the hotter the fuel the more it expands/lower specific gravity. As our injectors and systems work off fuel volume not weight there will be less BTU/energy per vol of fuel that is injected the more its temp increases. Consider how many times the fuel is put thru the heads based on tank size and pump flow. Then consider the effects as you get closer and closer to a empty tank. Figure temp in the heads at the fuel rails in the 200°F+ range of a fully warmed up engine. I am interested to see what the real world effects are.


For those looking for stock Bosch pumps they can be had for far less than fuelab pumps and no more than a Walbro if you do just a little digging.

One quick EBAY check yielded a few:

Bosch 0 580 464 074 is the pump you are looking for BTW

Here is the one for $99 http://cgi.ebay.com/ebaymotors/Bosch-F81-U-9350-AA-0580464074-Ford-Diesel-Fuel-Pump-/390108696313


The key is you do not want the full pump kit just the pump. When they sell as the kit the price goes way up as that's the typical retail way they are sold.



Always of course make sure the pump has the proper model number stamped on the pump body and should be made in Germany for this model. When looking for deals read carefully as some are selling other brands like cheap airtex cater or ac delco and then listing the bosch part number as an alternative part number meaning a cross ref but not what you are getting.

The Bosch 044 can be had for $180 with some checking but I would buy from a reputable place for these.

Bosch pumps come with check valve outlet fittings. As far as I know no one else do. This is why they do not create flow loops running them in parallel when one fails. It also helps extend the life of the pumps and prevent damage. Its all the little things that make Bosch pumps long lasting IMO.

 

[Strictly Diesel]

The Bosch 044 is one of the pumps I specifically discussed with Bosch, it is not rated for diesel fuel use (unless they have changed something recently) and has no warranty when used with Diesel. Like the Walbro, I am not saying that it won't last or work, just that the manufacturers don't recommend or warranty them with diesel fuel. From my limited discussions with pump manufacturers, it is my understanding that diesel fuel has a different conductivity than gasoline, which causes accelerated brush wear in wet motor pumps.

 

[psduser1]

Dennis, Tarm, thanks to both of you for your replies . Both well thought out and explained. The links Tom posted above is what I read before, and is what is contributing to my confusion, somewhat. I know that cooler fuel makes more power, seen the numbers firsthand on a dyno. Not huge gains, but still there. Having said that, I would agree that the basic design of the 7.3 makes a cooler on the pressure side almost useless for strictly making power purposes.
I'm more interested in maintaining (controling) temps at the tank for pump life and so forth. Granted, I've gotten pretty good life out of my current pump, and is like to continue that. Now that the fuel is returning from approx 210 deg heads, Dennis, your saying its a nonn-issue, based in x mi. of service. I can see the logic there. Thats the same lofic im using when I lean towards dual stock pumps as opposed to a Fuellab.
However, Tarms points about lubricity and viscosity are directlh related to that same service life. Theres just enough info to bug me!
iI think Ill run something for a cooler, not sure what yet. The biggest reason for changing my fuel system around after all is reliability.

 

[Tom S]

Tarm you are really good at recalling all this info. Do we have any long time Bosch 44 users.

 

[psduser1]

Tarm I've read your fuel system write-up and thoroughly enjoyed it! From what I understood, its a series style system, similar to what Dodges use (?).
Stock replacements 35-45 gph (per local dealers catalog)
Walhbro 55 gph, roughly 5% more
Fuellab/044 70-80 gph


Is there anything Im overlooking?

 

[TARM]

There are a number or 7.3 and a cummins user. The one I found specifically with the 7.3 and then swapped out the 7.3 for a cummins has over 50-60K miles on it with no issues. Another guy had it on one truck for a year and then sold it or something happened to it (can;t recall which and he now has it swapped onto another truck for the last couple years. I think I can dig up a link for at least a couple of them if needed but that is in summary what was reported.

I tend to log a good amount of miles with tons of key off and ons and I also run my pressure a bit higher than the majority @ 70 psi so if its going to be an issue I should see it. I am glad to be the forums test guinea pig per se.

Dennis,

I was given the same info as I was hounding the Bosch techs for a couple weeks striaght about what all they do to their pump and what not. While its not rates for diesel the way the tech put it to me without directly staying it was while they are not rated for diesel there are no internal differences in the pumps materials or design other than it being larger physically and higher flowing. To me that kind of got me the info I was looking for and had sort of figured was the case anyways. But I can see from a business position of selling pumps this would be a deal breaker for you as it would be hard to sell pumps specifically for diesel setups that is not covered by their basic warranty.




I have to say the tech for Bosch were very helpful as I really picked their brains on stuff. I have to say I learned a ton and beyond that in being told all the little things done in the design of Bosch pumps my positive opinion of them grew. From all the positive and damage prevention their addition of a simple fast acting check valve to their pumps adds to the thermal overload circuit to prevent pump damage from over heating along with the coatings on the various internal components.


All I know is I have learned a ton in doing this last fuel system and I think I have arrived at as good as it can get for the 7.3 within reason. If for some reason I have an issue with the main pump then I am going to a full out gear or belt driven pump for the ultimate in fuel delivery and long term durability and toughness. Not to mention simplicity once installed. But I am very happy currently with the setup I am running in the previous post link.