Engine/Transmission (1998.5 - 2002) Modifying fuel system so temperature input to VP44, 80* - 100*, your inputs.

[Gary - K7GLD]

Even with the top removed from the VP - it's still difficult to know by exactly from what path/direction the fuel is flowing in those pics.



But yes, I too am curious as to exactly how close the contact is between the fuel in that cavity and the actual components on the PSG board. I can't imagine the individual electronic components are literally immersed in the fuel - and if not, what barrier is in between them?

 

[rweis]

Well, the PSG could be immersed in fuel. No O2, fairly hard to ignite fluid (high flash point, or fairly high at least), low voltage, I have no idea of the conductivity of diesel (ie ability to short circuit electrical components), I do not know, should not be too hard to run an ohm meter conductivity test though.



I think this is the first time we have seen the PSG compartment opened on this board. Interesting, thousands of failures, literally miles of threads, years of trying to figure it out. Years of frustration. Like the first pictures of the moon. What to make of it?



I am thinking that I am going to call Southeast Power Systems (local pump rebuilder) and ask if I can go to their facility and see and ask questions. There are a couple of Vp44 rebuild technicians here on TDR. Sure would be nice to hear from them.



Opens up whole new vistas and directions. New meaning to the term "cool fuel"? I do not know,



I am still going to do misting test though, and proceed along thermal lines. Keeping the VP temps down can't hurt it in the summer, just turn the mist off in the winter (below 50*?).



Bob Weis

 

[The Adjuster]

Well heck guys ... why didn't you say you wanted more internal shots ...



Here are a couple more for you to view ... no diesel on the circuit board.



Kevin

 

[NoSeeUm]

Finally made it through the whole thread. Like I said earlier fuel bombing is my next project. In my case I am going to install a 12 valve LP (if I can ever get Rip on the phone) as well as an electric LP mounted on the frame by the tank. As I conceave of it right now, the mechanical and electrical pumps will have full flow bypass valves. The mechanical will be the primary, while the electrical will be the back up and used for system priming. I plan on installing a switch in the engine compartment to enable and / or turn on the electric.



From what I can gleaned from the previous 33 pages is that, as far as fuel cooling is concerned, the low hanging fruit is:

• Installing spacers to give the FF some clearance from the hot engine components and possibly provide some insulation
  
• Install a fuel cooler (Mundyver's) ahead of the engine radiator with a full flow bypass installed in the fuel line downstream of the FF
  
• Rig up some insulation between the VP44 and the hot engine components
  

The VP blower ideas look interesting, especially Gary's which is really high tech. But I am going to wait on that.



Thanks to all the contributors of this thread, and especially you Bob W. You have certainly positioned yourself as the Poster Boy concerning fuel cooling.



Jim

 

[GWedekind]

ADJUSTER, do you have a pic of the underside of the PSG module without the plate? If im looking at that pic corectly , pic #1 is the top of the module with the cover ( #471 )removed and pic #2 is the bottom plate that seals to the VP but they may be able to be seperated to see what is in the middle. I think that is where we will see the diesel actually making contact with the psg.

 

[rweis]

JFaries - Never heard the term "low hanging fruit", I like it though, like picking oranges down here.



Take your own temp readings when you make your changes, but I think your #1 and #2 will off set themselves. The ff is aluminum and I think picks up a lot of the engine compartment heat. The up front fuel cooler is a better place than where I have mine under the bed. Still a problem when stopped or hung up in traffic for any period of time. Of course, how often does that happen and for how long? I would tend to figure a fan for it. but there is very little room up front and with my ETC my transmission cooler is up there.



#3 no doubt, here we have another aluminum heat sink almost touching the biggest heat producing item we have.



VP blower - Assuming we keep it cool while running, shutdown and then everything we have worked for gets minimized. I feel the after shutdown blower rankes right up there with insulating the VP from the engine and the fuel cooler. Some guys raise the hood, which is a valid way to do it if you can and have done the insulation. A hood scoop that will let the engine compartment heat out (ie not cosmetic) I think would work as well.



Do some temp sampling of the block and the VP body at shutdown and every 1/2 hour after shutdown a couple of times and see what you get. Stays warm for quite a while. BUT how warm is TOO warm for the VP?



Some more pics on the PSG and some discussion on how the fuel flows aroung the PSG compartment would help if possible. Sort of a from where, through where, on its way to where.



Thanks to all for inputs, I will try to get the 1st iteration of misters installed this weekend and will let you know how that worked.



Bob Weis

 

[Gary - K7GLD]

Some time back, I removed the top cover from a spare VP, and posted essentially the same TOPSIDE pic of the PSG - but didn't dig deeper. Obviously, that topside reveals that NOTHING of the actual individual electronic components is visible - just a protective overlay/membrane.



A closer look at the bottom pic leads me to suspect that the shown lower metal partition seen beneath the PSG, and the PSG itself are a SINGLE composite unit - possibly bonded together with a heat conductive material for maximum heat transfer from the PSG to that partition, then to the fuel in the lower compartment, without the PSG actually coming into contact with the fuel.



Even the included drawing displays that lower metal component and the PSG as a SINGLE unit...



We know that these electronics CAN be directly immersed into fuel - both gas and diesel, since the Carter fuel pumps and other in-tank pumps, have been doing it for many years, again, primarily for the cooling effect that provides.



One curiosity in the large cavity we see on the topside is, how/where does entrapped air get vented? It sure looks as though any significant air trapped there might compromise PSG cooling to a degree (pun).



This latest info and pics are sure interesting and thought provoking!

 

[GWedekind]

Air is most definately trapped in that cavity. The fuel can only go through that little hole which means that the overflow valve sees the air pocket before the VP sucks it in. Maybe a true return system with a regulator at the overflow valve port will 1) help recirculate the air pocket back to the tank 2) allow recirculation of fuel after shutdown to help "cool" the PSG module and some of the VP.

 

[Sled Puller]

Stupid question:

I'm in the process of putting a 1st Gen Cummins in a 99 V-10 truck.

I dropped the fuel tank, drained it, and realized it has an in-tank pump.



I'm going to use it, with a regulator.



Would this be a simpler fix for the 24 valve trucks?

 

[Texas Diesel]

Be sure and post how that turns out. The gasser pumps put out 35PSI so your regulator idea is a good one.



Contrary to other posts the motor part of the OEM LP is NOT, repeat NOT fuel flooded. Nor can anyone assume that unprotected electronics can be flooded with gasoline or diesel fuel.



(shhhhhhh, dont tell Gary)

 

[GWedekind]

Texas... the OEM ( carter type ) lift pumps do get fuel flooded. So do the P4601's, Aeromotive A1000's and a few others that I cant recall. I took apart a factory LP and a Carter P4601 and they have the same design where fuel cools the motor/ windings etc. The difference I found in the OE and P4601 was the internal pressure regulator.



I had some pics on TDR of the above scenario... somewhere on here.



I dont think the PSG gets flooded BUT i bet there is some sort of pressure transducer inside the PSG module that does see fuel. I saw the port ( and there is a pic of it on this thread ) where fuel flows upward into the PSG . I wish now that I would have split the PSG from the bottom plate to see for sure what the rest of it looked like. Just give me another 6 months and I will have another dead pump to disect

 

[Gary - K7GLD]

the OEM ( carter type ) lift pumps do get fuel flooded. So do the P4601's, Aeromotive A1000's and a few others that I cant recall. I took apart a factory LP and a Carter P4601 and they have the same design where fuel cools the motor/ windings etc. The difference I found in the OE and P4601 was the internal pressure regulator.

For those interested, here's a pointer to my thread on the internal construction of our stock LP's:



http://turbodieselregister.com/forums/showthread.php?t=108275



And yes, fuel definitely DOES flow THRU the motor section...

 

[PRout]

I hate it when that happens. . #ad
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[Gary - K7GLD]

I hate it when that happens. .

It WOULDN'T happen, if some guys were more interested in positive contributions than they are in obsessively stalking others in a deliberate effort to get under their skin...



Odd that the moderators don't seem to catch on to what's happening, and why...

 

[PRout]

Odd that the moderators don't seem to catch on to what's happening, and why...

Bingo. . Was kinda wondering about that myself.

Stalking must be ok as long as nothing bad is said about an Amsoil product.

 

[GWedekind]

SOOOOOOO.....



Maybe a gasser intank pump, gutted overflow valve with a return style regulator right after the overflow valve and route the return line to the filler neck?



Then add a timer to pump fuel for X minutes after shutdown.

 

[The Adjuster]

Bob,

My rpm @ 75 MPH is 2100 ... @ 90 MPH is 2550 or there abouts (ever notice there are only 4 strokes on our tach's per 500 RPM and not 5).

Did a run today started from cold AOT 92*, fuel at startup was 76* 2mins into the drive fuel was at 93* ... cruised at 1500 RPM for 30 mins ... fuel temp was at 98*.

Cruise at 75 MPH for another 30 mins ... fuel temp 120*. Parked truck for 30 mins ... fuel temp at starup was 152* but quickly went down to 123* once engine had idled for a few minutes ... but sitting in the TX sun at AOT of 92* after a 1 hour drive sure makes that VP soak some heat.



Gary & GWedekind,

Have a VP44 here but cannot find my 5 point tamper bit to get the cover off ... will post pics when I get it off but if I remember correctly it is bonded to the alum cover plate. Gary ... did you see your post count ... nearing another milestone ... man you can shoot the $hlt with the best of em ... :-laf .



have a good one guys



Kevin

 

[GWedekind]

call me Glenn

 

[Gary - K7GLD]

SOOOOOOO.....



Maybe a gasser intank pump, gutted overflow valve with a return style regulator right after the overflow valve and route the return line to the filler neck?



Then add a timer to pump fuel for X minutes after shutdown.

Not as I understand the flow path inside the VP-44 - this quote from a related thread:

In the low pressure side of the VE / VP series the Outflow valve has nothing to do with the input 14 psi pressure. The outflow valve comes off the solenoid back side by the spring to cool the solenoid. It has zero to do with the 14 psi input pressure.

As I understand it, there is NO direct flow path from the inlet to the outlet (overflow valve) of the VP-44, and LOTS of internal blockages in between that make it impractical, if not impossibe to get significant fuel flow in that path.



But I'm ready to be edumacated... :-laf

 

[The Adjuster]

Sleddy,



The only problem you may have with the gasser pump is volume, pressure should be good but I think you may pull it to 0 PSI with a good WOT run ... but try it and keep us posted.



I run 2 x holley blues in parallel so still only get 14 PSI with no regulator (even with both pumps running) ... one pump runs on start up ... the second cuts in when one of two conditions are met ... boost is highter than 15PSi and/or fuel pressure drops below 8 PSI ... plenty of volume and PSI still within Cummins Specs.



Kevin