KATOOM

wyododge, absolutely diesel can be used as a cooling agent. Just as engine oil cools an engine. There’s guys running fuel temps around 150*. How would that be possible if diesel wasn’t cooling anything when the injection pump is connected directly to a 190* engine? Diesel is a liquid and for that reason it will absorb heat and transfer it. You right though about causing your tank fuel temp to rise which is the reason I think its critical to keep the pressure just above the overflows pop off mark and why I think that 100 gph pumps are more than adequate instead of guys installing 150+ gph pumps. (unless that amount of fuel is needed for HP) That extra volume is supplied through ½” lines but then is simply being shoved through the 5/16" return lines, which maybe isn’t a problem at all but seems kinda contradictive to me. You cant get it all there with a garden hose and fire hydrant only to ask a squirt gun to bring it back. So whether or not you can cause your entire tank to get as hot as the returned fuel would only have to be tested. I’ve touched my tank after driving all day in hot summer weather and it still felt relatively cool. The fittings on the Raptor were not so hot I couldn’t touch them either. Point being is it’s a good theory but will it happen. Maybe the possibility gets more plausible as the fuel level gets really low which would be a good reason to keep at least half of a tank during the hot summer. As for the 5psi thing Chip has tossed into the mix, well I think we're going to see him retract that soon since he's realizing (after speaking with him personally) that his test was on a dyno and they never even cranked the fuel pressure up past 10 psi. So, NO, he wouldn’t have seen any substantial cooling gains from the fuel until he reached the point were fuel was passing through the overflow valve, which isn’t until 14-16 psi. And lastly, the fuel requirements for lubricity in diesel is still in ULSD but even at that Bosch stated that their new updated pumps are fully compatible with ULSD. Then the way I see it is that if ULSD lack of lubrication was really the problem that it was all cracked up to be then there would be diesel engines broke down all over the place with bad injectors and injection pumps. And that being all brands and manufactures too because diesel fuels lubricating ability is the only thing keeping diesel engine fuel systems from failing. The VP44 wouldn’t be the only injection pump out there to suffer from ULSD. For over 10 years now, people have been trying to solve the mysterious reasons the VP fails and I think we're getting close.


bent valves, although you sound intelligent, your comment simply isn’t true. More fuel is definitely allowed to pass through the VP than it requires at the time. Otherwise, 1) it wouldn’t have a return line and 2) its been visually proven. The internal vane will allow more fuel to pass while running but supposedly not when the engine is off. Although I achieved fuel dribble through the VP at the injectors without the engine running with a OEM lift pump. So.....
Yes, it’s a positive vane pump which cant be forced to pull fuel on its own or the diaphragm tears which allows fuel to leak past, causing fuel timing issues, vibrations, and eventually beats the piston and rotor to failure. Which is the main reason we know anything below 10 psi is very bad.
Also, your comment regarding the setting of the fuel regulator is only a determing factor to what the requirements are actually of.....and at this point, no one really know what the high limit pressure factors are for the VP. So your right, but only if we knew what the figures were. With guys running 25 psi and up to 40 psi with no issues, I’m not sure if we’ll find out.
And lastly, I dont think any of Chips comments (in no defense to him either) has anything to do with the fact that he sells lift pumps. He's always sold the OEM lift pump with his 5 psi theory but now has started selling FASS only because I think he's starting to see the light. Which is the key reason why he finishes his web page by saying that he'd like to hear from anyone regarding thoughts and experiences with the new idea of running higher fuel pressures. Chip is simply as perplexed as the rest of us because as he stated to me, he has a guy that has over 700,000 miles on one VP but has another guy that cant get a VP to last over a year. Go figure.
I honestly feel (and so do many others) that its all heat. Heat is destroying these injection computers. I haven’t heard of a "replacement" VP that’s failed because of some mechanical reason. They've failed because of computer reasons.

But back on topic. I think the belt pumps are a great idea and I'd like to see more people try them.

wyododge

Ok, hate to hijack again, but KATOOM are you staying that the relief valve is on the 'back side' of the pump? Meaning that the fuel goes through the pump and then out the relief valve? Just by looking at the VP it looks as though any excess fuel is immediately dumped.

Back on topic again, Looks like the redundancy of the belt driven pump is the way to go. Redundancy is ALWAYS better. Especially at the same or just a little higher price.

bent valves

KATOOM, I respect your opinion but have you investigated how the VP44 is built? The positive displacement pump built into the IP passes a fixed amount of fuel for each revolution of the pump. A higher external lift pump pressure does not change that. The internal pressure inside the pump before the high pressure stage is above 85 PSI at idle and increases with RPM. Tell me how increasing the lift pump pressure from 10 or 15 PSI to 20 or more can have any increase in flow when the internal pressure is higher. It can't!

Here is a direct quote from Cummins about fuel pressure and temperature:
Quote -------
Concerning lift pump pressures for ISB 24 valve engine, in the Ram application,
the following information is from the Cummins ISB Troubleshooting and Repair
manual, Bulletin number 3666193. This information applies to engines having the
Bosch VP-44 injection pump (not the high-pressure common rail found on 2003 or
later models).

The lift pump pressure is only one parameter pertaining to fuel system
operation/diagnostics, and as long as you have positive pressure to the VP-44 at
adequate flow, your engine should run fine. "Adequate" means normal performance,
starting and smoke levels. Any issues with the engine running outside of the
below listed pressures being in their respective proper ranges should be addressed.
The numbers in the manual are:

Idle speed:
700-1000 rpm
Maximum fuel inlet restriction to lift pump:
6 in Hg
Maximum Fuel Pressure at Fuel Filter Outlet (engine cranking): 4 - 8 psi
Minimum Fuel Pressure at Fuel Filter Inlet (engine running): 8 - 17
psi
Fuel Drain Line Maximum Restriction:
10 psi
Fuel Inlet Maximum Temperature:
165 deg. F
Engine Minimum Cranking Speed:
150 rpm
End Quote -------

The above does not address the problems with the VP44 and I agree heat may be the problem. Increasing lift pump pressure is not the answer.

This argument has gone on for years. So I'll just back out now and not dig up old bones.

johnh

what's the big deal on aftermarket lift pumps? I've been running oem style pumps for over 200,000 miles with no problems.........maybe more is expected out of them than i'm getting..........maybe better mileage, 19 +, more power,last dyno was 484..............maybe it's just a little tinkeritus

KATOOM

bent valves, as I do respect your opinion but.....we have to agree that not only has Dodge been kinda weak on VP knowledge since they have nothing to do with the pump especially since it simply came with the engine that they didn’t even manufacture. So with that said, I cant imagine Dodge investing any research and development on the VP to justify them putting out a respectable bulletin on VP requirements. This info probably came from either Cummins or Bosch but certainly not both. So my point is that I think us VP truck owners have been feed a lot of info over the past decade from three companies who aren’t really sure themselves what the VP needs. Especially Bosch. If they did, we wouldn’t be having this conversation. Not to mention, the word "should" was used to many times in that bulletin for them to be sure of anything.

Also, yes, I actually have investigated how the VP is built and I fully understand what you're saying regarding the VP and external pressure but no matter, I personally have had fuel pass through my VP while the engine wasn't running which is not supposed to happen and there's others who've witnessed their return fuel flow increase when changed over from an OEM LP to an aftermarket FP. And if the fuel wasn't passing through the VP then why does the fuel temp increase as the fuel tank level drops if fuel simply sits at the VP until the engine needs it? What I mean by that is, yes, you're right that only a specific amount of fuel is used by the VP to run the engine and no amount of additional pressure is going to force the VP to use more but that doesn't mean that any additional amount fuel over than what the VP needs isn't bypassed out the return. This is the ONLY reason running higher pressures over than what the VP requires for positive pressure, is good. By forcing extra fuel to pass though the overflow valve, you're basically turning the fuel tank into a gigantic radiator. I knew of a website that showed detailed pictures of a VP44 taken apart but as usual, I cant find it.

Good talk though.

KATOOM

Ignorance is bliss. You better knock on some wood fast.

NICE_N_EEEZ

Will this website help?
Large vp44 cutaway pic which you can actually enlarge when you click on it>>>http://www.schule-bw.de/schularten/b.../vp44farbe.jpg

Regards NICE_N_EEEZ

NICE_N_EEEZ

Hey guys,...just did some HEAT readings with a thermal laser on my truck to see how fast the temps on the VP44 CPU are climbing.
The Thermal laser used is an EXTECH 470 true rms multimeter with build in Thermal laser thermometer at a distance of 16 Inches it measure's a 2" surface!
Tech specs about the EXTECH 470 can be found here>>> http://www.extech.com/instruments/re...EU-EN-V2.1.pdf

MY local (North East Texas) weather at this moment is:
Humidity: 46 %
Wind Speed: SW 14 G 23 MPH
Barometer: 29.99" (1014.5 mb)
Dewpoint: 70 °F (21 °C)
Heat Index: 100 °F (38 °C)
Visibility: 10.00 mi
SOURCE: NOAA

My truck is by the way BLACK,...which ofcourse does NOT help keeping things COOL!
Ran every test within 10 seconds after opening the hood

Cold engine (without having it ran at all) cold VP44 EDC electronic diesel control unit case temp 120F
(20 degrees hotter then outside temp!)

Inside cab without running A/C :
in sun 185F
in shade 147F

I let my engine idle for 15 minutes (with a closed hood!)
Again I ran every Thermal test within 10 seconds after opening the hood
at the time of this thermal test I let engine running @ idle:
-Water temp 185F
-Turbo temp 220F
-Manifold temp 295F
-VP44 EDC electronic diesel control unit case 150F


Thats a 30F degree difference in just 15 minutes @ idle!
You can probably multiply that number by 4-5 if your engine is actually pulling something.
Unfortunately my thermal laser can only measure from -58F to 518°F.
Sooo a HOT test (running the engine with a WOT for a little while) and then testing is not possible with this unit,....the temps will go far beyond its capacity!


Anyway,...I guess that HEAT on the VP44 CPU is an "old" problem, according to some people.
The manufacturer BOSCH or the dealers will not do anything about it, cuz that will cause less sales in VP44's/cost them business!

Unfortunately I aint no mechanic, welder, machinist, or pipefitter,.....but I do know a bit about Engineering!
I have a pretty SOLID IDEA (in my head) on how to ELIMINATE this evedently common HEAT problem,.......
It's gonna take a while though,.... I still have ALOT to figure out;....
-COST,
-Make a prototype
-Testing it,....
-Patent it,...
and then bring it on the market!
Someone has to figure something out,......seeing that noone else does!

Regards NICE_N_EEEZ

NICE_N_EEEZ

Thanks Nick02Ram!
THATS EXACTLY what i'm looking for,.....reliability, and the piece of mind that IF it goes wrong your OEM pump will take over without killing your VP44!


Your PSI's are quite high,....is a regulator coming with this set so ya can reduce it?


Common guys,....is there anyone else here who uses belt driven pumps?

Thanks again
regards NICE_N_EEEZ

mstep3

If this article in this thread is true then that must mean that I'm damaging my injection pump.....I'm using a FASS DDRP and my fuel pressure stays at a constant 20psi at idle....that's the way the pump was set from the factory....Is this not good to have the fuel pressure this high?

I've heard several people that are pretty knowledeable & they recommend keeping the fuel pressure at 19psi at idle & not let it drop below 15 WOT.....i'm not too sure who to believe....

KATOOM

Not to steer anyone from this site since there's lots of great guys here but you might find some belt driven pump users on the http://cumminsforum.com website.

And lets talk about your temperature readings. All in all, what you found sounds about right but given what I've heard from others who've performed similar tests found that their fuel temp was in the 150*'s range and the VP itself was not so hot that you couldn't place your hand on it for a few seconds. That clearly tells me that their fuel is keeping the VP from reaching the same temperature as the hotter engine its bolted to. No matter, I'd love to see any idea you have to keep the VP cool. Maybe you have the solution no one could come up with yet.

Now I've heard that because we all know that its not the VP pump itself which cant take the heat as much as it is the computer on top of the VP. So there's already been guys who've tried to relocate the computer away from the VP but the frequency signals bouncing around under the hood caused all kinds of issues with the computer and the computer and its wiring isn't shielded enough to stop any outside influence. Plus adding length to the computers wiring system in order to relocate it caused problems too. So that didn't work.

I think that the few people who've rigged up a simple fan and ducting to allow outside air to blow on the VP are on to something. The VP is tucked back behind the timing gears which keeps direct air from blowing on it and that cant be good. Which means the VP has nothing to keep it cool but the fuel. One guy even claimed an increase in mileage with this setup.

The only idea I could come up with was to run a fuel cooler. And the only problem I thought would be an issue would be what to do in the winter months and a fuel cooler would be most effective cooling supply fuel instead of return fuel but then you end up with more fittings to leak and allow air to reach the VP. Oh there's always something. And to note that in my search someone showed me a fuel cooler fitting that hooks directly into the air conditioning system from some European diesel car. Apparently they thought cooling the fuel was necessary.

And mstep3, if I was you, I wouldn't worry about your fuel pressure. Who to believe? Well just note that everyone clearly knows low pressure is bad for the VP but NO ONE knows what amount of pressure is to high. But with that said, I haven't heard anyone say that their (replacement) VP failed because their FP was to high. I say replacement because there's plenty of guys who've installed a FASS or Airdog on their OEM VP only to have the VP fail in the near future. That doesn't mean that the fuel pump caused the problem but probably the OEM VP already had issues from the OEM lift pump which they replaced after finding that their fuel pressures were to low or they had no pressure at all.

I run a solid 19 psi at idle and 15-16 psi WOT and I'm not turning my Raptor down until there's positive proof that pressure that high does anything bad to the VP. Especially since one of my OEM lift pumps almost ran at 16 psi at idle.

NICE_N_EEEZ

I hear ya.

20PSI is the maximum undocumented pressure the vp44 can handle,...to quote most diesel specialists:
-Mopar1973man: http://forum.mopar1973man.com/showth...Specifications

-Blue Chip Diesel:http://www.bluechipdiesel.com/index.html

-Opie:http://www.opieparts.com/Products.htm

-Glasier Diesel Power:http://www.glacierdieselpower.com/pr...pf_id=FB-98502



Each and everyone of the above companies have DIESEL as their specialty!
And are all recommending to NEVER let the pressure drop below 10 PSI!
And NEVER to go higher then 20 PSI.
The Overflow pressure valve is set for 14 PSI,....sooo to have a continious fuel stream to cool your vp44,...i guess we'll have to set the pressure inbetween 14 & 20 PSI.

Now to take the "cooling" idea ONE step further,...(well at least that's what I'm considering),...you could add a FUEL COOLER with fan!
DANA FUEL COOLER SYSTEMS: http://dana.com/Automotive_Systems/P...roverview.aspx
That way you'll cool from the INSIDE-OUT to keep your VP44 CPU cool!

Next to that i'm thinking about creating/designing something to cool the VP44 & CPU from the OUTSIDE IN at the same time!
I have a pretty SOLID IDEA (in my head) on how to ELIMINATE this evedently common HEAT problem,.......
It's gonna take a while though,.... I still have ALOT to figure out;....
-COST,
-Make a prototype
-Testing it,....
-Patent it,...



Quote from Mopar1973man.com: "Now take notice to the overflow valve is set for 14 PSI so excessive pumping of fuel does nothing for performance except create more heat for the fuel, which in turn reduces the cooling ability of the fuel and adds more stress to the lift pump. So a little extra fuel pressure is a good thing because it insures the VP44 stays cooled and lubricated properly.

But excessive fuel pressure will heat the fuel and reduced the cooling ability of the fuel.
Now always remember that the only lubrication the VP44 will see is the fuel itself so if you don't have enough fuel pressure it will cause damage to the VP44 injection pump.
It's like the same as running the engine with low oil pressure it will continue to run but the damage to the engine will occur.
Or in this case the VP44 which happens to be about $1,200 to replace."

Yeah,...been doing "some" research lately

Regards NICE_N_EEEZ

KATOOM

NICE_N_EEEZ, you and me are going to get along great. I'm what you'd call a research ***** too.

Again, I'd love to see what you have floating around in your head for cooling the VP.

NICE_N_EEEZ

Tried to sign up with that forum,...but it somehow wont let me?!?!?!? i guess theres something wrong with their server or something.
Running a fuel cooler should not cause any problems as its mounted in the RETURN line.
[EDIT]I guess you could mount a secondary cooler in the SUPPLY line aswell,...the cooler your fuel the better!
Even in "Winter" time you should not have any problems,...infact most vehicles,...if not all run BETTER in cool areas the in hot areas,....just my 2c[/EDIT]
Cooling your fuel actually should INcrease HP and responsiveness and reduce wear and tear on your engine, VP44-CPU, ect, ect


Why cool your fuel?
There are a number of important reasons. First, extremely cold fuel temperatures mean significantly colder air charge temperatures as fuel and air mix in your engine prior to combustion.
As the air cools, it becomes denser and this increases the amount of oxygen available for combustion, resulting in greater horsepower and torque.

For example, if absolute pressure is held constant and temperature and humidity are changed from 77 degrees F, 0% humidity to 95 degrees F and 70% humidity respectively, relative horsepower drops to 93.5%.

In other words, your engine is now producing only 93.5% of the horsepower available to you under the standard conditions described.
If, however, you are able to cool the air charge to 50 degrees F as a result of significantly cooler fuel temperatures, your relative horsepower jumps to 102%.

The difference between the two numbers is a whopping 9%. As the humidity level increases, so does the percentage difference. At 90% humidity (not uncommon in the Southeast during the summer months), the horsepower differential increases to 10%.


To help understand the reason for this significant horsepower improvement, we can look at the Air Density and Density Altitude numbers calculated by the formula for these two scenarios.
At 95 degrees F and 70% humidity, the resulting Air Density is 1.102 kg/m3 and the Density Altitude is 3560 ft. When the air temperature drops to 50 degrees F, the Air Density increases to 1.214 kg/m3 and the Density Altitude plunges to 307 ft.
This means that for two racers competing under these conditions, the one who's not using a Fuel Cooler would be racing at the thin air equivalent of 3560 ft (2/3 mile above sea level!), while the other one WITH a Fuel Cooler would be racing at the denser air equivalent of 307 ft (basically at sea level). All other things being equal, the racer using a Fuel Cooler would obviously have a significant advantage.


Another important benefit of cooling your fuel is the overall cooling effect it has on your engine. Think of the super cooled fuel as an additional coolant. Lower operating temperatures mean less wear and tear on your engine.
In the long run this could result in significantly lower maintenance costs your VP44 and CPU might last longer!
The Fuel Cooler could conceivably pay for itself in the first season, especially in the Southern HOT summer states/days!

Makes sense dont it?

Regards NICE_N_EEEZ

wyododge

The return lines are metal, I think steel, so why not just add some heat syncs to them. Similar to a radiator? or better yet like a hot water baseboard heater? Wouldn't be hard to add it under the truck, and remove it in the winter. Heck, you can get them pre-built, no moving parts either.

Never seen professional ones, but it seems as though ambient temperature is not gonna ever peak out above 120* that right there is a 30 degree temp differential for the heat sink to pull heat out. Probably would not need more than about four feet on the return line.

If a guy wanted to, you cold make a 'summer' hard line, and hook it up once temps got above say 50 degrees. Then switch back over for winter.

The only time you wold not benefit from the air stripping heat is when stopped in traffic, but the tank of fuel would supply a rather large reservoir of heat capacity and you would still get some benefit from the heat sync.


Just a thought.