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

[BDanner]

We had a short delightful conversation about VP44s and the topic you have been addressing, as well as the low pressure issues.



What were some of the comments? Might lend some insight as to direction to point to for lessening the impacts on the VP44.



Bob Weis

Most of the things he addressed were things that have been hashed out here in our forums. His first comment or warning was about the low pressure death of VP44s and that the block mounted lift pump was a problem. The fix of putting the pump in the tank as a warranty fix was addressed. I did explain to the engineer that it felt to most of us that Dodge has been skirting a serious design flaw issue in order to buy the needed time to separate most of us from any warranty claims either through miles or years. He just nodded and felt my pain.



He also had great things to say about the new 3rd generation of quiet diesels with a boyish grin like that was his baby. This gentleman enjoyed seeing good modifications that make the CTD motor perform. His employee parking lot at work sounds as though it is filled with Ram Bombers, TDIs, Fordges and other diesel vehicles.



I wish I had greater wisdom to pass on, but it was a quick 10 minute exchange with both of our wives giving us the "Lets Roll Look. " My wife could preach a CTD sermon also, but she too was ready to head home. HWY 68 & 70 are gorgeous right now through the Cumberland Gap!!



_________________________________________________________

Bruce in Northern Virginia



Ready for the infamous TDR seat bomb in the '01, my **s hurts! :-laf

 

[BDanner]

That is a nice job! One more valve and you would have a great theft protection device!



Could you post a part# for that cooler for us?



Bruce in Northern Virginia

 

[rweis]

Short answer - yes



I screw together my own fuel (etc) lines.



I use AN-6 lines and all full flow fittings. Except for the OEM line comming out of the tank to the frame area just forward of the tank all the fuel lines going to the RACOR 690, lp, RASP, inline ff, VP are AN-6. I left the OEM fuel return line alone until it got down to about the transmission cross member support then it is AN-6 back to the H7B and tank vent line.



I have on order a couple of CNC fittings for the tank cannister top comming that will insure ALL the fuel lines are 3/8" or AN-6. I still draw the fuel from the OEM tank cannister and will probably continue to do so. There is an excellant thread about repairing the OEM tank cannister ($60 vs $400 (DC)) with better bolt hardware and replacing the top 90* (NOT full flow fittings) fittings with full flow fittings, and rebuilding the internals of the tank cannister.



Bob Weis

 

[Graphic man]

Bob

do you run your LP all the time with the RASP?

 

[rweis]

Short answer - lp & RASP are both armed and functional at the same time.



The RASP has a pressure switch in the system. The lp is wired to that pressure switch. When you first turn the key to on before the start position there is no pressure in the pressure switch and the lp will run for about 1 second. Enough to know that 1. you have a pressure rise on your gauge and it is pumping, 2. you can hear it run.



When you continue to the start position the starter starts rotating the engine and in about 1 - 2 seconds you have ignition. As the rpms start up from zero the RASP starts pumping. I think I calculated the ratio of the pulleys of the RASP at ~1 (crankshaft) to ~3 (on the RASP). At 800 rpm (not warmed up) I get 13 # on the RASP. The pressure switch is set at 8#. Below 8# the lp switches on, above 8# the lp switches off. This is the safety feature of the RASP system so if the belt breaks or whatever, the lp takes over.



Some have intentionally taken the belt off prior to engine start to test the pressure switch and lp backup system. Of course only for a test and not to run for any appreciable amount of time.



Bob Weis

 

[Graphic man]

I too run the Rasp with the big line kit, but you said you get 16psi above 1000rpm and will not drop?



i set mine at 14 psi (REG), 13psi @WOT and under normal load 12-15psi, in gear hot 11psi



Thanks

Scott

 

[SKneeland]

part number for the cooler is B-M 70273

 

[rweis]

I was going to "tweak" my RASP bypass regulator, but I want to get the VP shutdown / cooldown temperature control figuered out first. I know I have a tad (2 psi) above optimum, but I want to cross check that with one or two other gauges before I take that as "gospel". Just because you have a gauge does not mean that gauge is accurate unless you can verify it with an independent measurement.



I run a lot of fuel line and what I am reading vs what is actually right at the VP input port could vary. I actually read the VP input psi off the bypass return line about 4' from the T for the bypass. Fluid psi should be the same throughout, but seldom is in reality. So I am not going to get into tuning the VP input psi until I get my arms around the heat soak problem.



Bob Weis



I checked the heatsoak at lunch from this a. m. drive. OAT 82* at shutdown, EBC at shutdown 110*, heatsoaked to 129. 7* and ??? on the actual internal temperature. I am beginning to wonder if there is a OAT +30* to shutdown and an OAT +50* to heatsoak? Could be I am only seeing the consistancy because I drive the same way, same speeds, same distance.

 

[rweis]

More data:



I have checked leaving the hood open on engine shutdown to lessen the heat soak. At OAT of ~80* and heat soak to 130* the heat soak is 120* - 125* ie knocks off about 5* - 10* off the heat soak. This is after 5 heat soaks trial.



The ~80 OAT to ~ 130* heat soak is being real consistant day in and day out. The shutdown EBC temps are being real consistent OAT + 30*. This weekend I will take a longer (35 mile) stop and go across town type trip, ie max 50 mph lots of stop lights etc. And we'll see how the temps go.



Bob Weis

 

[RAJohnson]

More data:



Normally I run at 1400 rpm (best fuel milage) on the way to work. As reported above the Vp electronics bay cover temp (EBC temp) was 113*. This afternoon on the way home from work I took the Interstate for an extended didtance to see what if any difference there was in EBC temp.



The first run was in O/D as you would normally drive the interstate. @ 70 mph ~ 2000 rpm the EBC temp stabilized @ 118*. I drove about 30 miles. Tank @1/2, OAT 90*, tank temp 98*, VP fuel input temp 100*.



The second run. When I tow my 5er I tow O/D out so I have more rpm and torque. @60 mph ~ 2400 rpm the EBC temp stabilized @ 122*. The same 30 miles. The same tank @ 1/2, OAT 90*, tank temp 98*, VP fuel input temp 100*.



Both runs were not loaded (ie empty).



When I got back onto secondary roads and O/D in and slowed down to 55 - 60 mph (from the 2400 rpm run) the EBC temp dropped right back down to ~ 116*. The drop was like in 1 minute.



I had always assumed that more rpm meant more fuel bypassed as well as available and a cooler VP. The slower mph but higher rpm run netted higher VP EBC temp. Now the temp difference is only 4*. When I slowed down to secondary road speed the EBC went to 116*, and when I tried my 1400 rpm 51 mph it netted the same 113* as I have seen on several days. (I drive @ 1400 for fuel economy. (I know the overhead console is not numerically accurate, but the best mpg and keeping the T/C locked in O/D is 29 - 31 mpg on level road (turbo whine pitch constant ie steady state rpm)). The T/C shifts into O/D @ 1200 rpm and I add 200 rpm to keep it locked in O/D to compensate for any terrain variation)



The coolent temp on the interstate runs was 2 needle widths (~1/8") below 190* mark on the gague (180*? (I have a 180* thermostat)). The coolent temp on my work drive @1400 rpm is normally about 3 needle widths (~3/16") below the 190* mark on the gauge. (Yes it does go up to 190* as the thermostat warmes up then as the thermostat opens it drops to 2 needle widths below, then as it stabilizes it drops to 3 needle widths below)



I appears that more rpm = more VP temp, less rpm = less VP temp.



Bob Weis

Bob, I have been reading and keeping up with this thread. Thanks for all the good info. Keep up the good work.



I have not had any problems with my VP to date. I faithfully watch FP & EGT when driving. I think you hit the nail on the head in the statement you made about RPM=more or less heat depending on your driving style. I too typically run my truck @ 1400-1500rpm with my GV overdrive. I guess it would be safe to say I lug the HE__ out of it, and only shift when EGT start to get above 1000*. But I like it best when it runs 1400-1500rpm and 600* EGT for milage. For a note my EGT sensor is pre turbo.



I was wondering if people who have lost a VP for one reason or another, and I know many are for lack of fuel (IE: bad lift pump) but if those that feel they had good fuel pressure, where possibly driving at higher EGT and RPM that might be deuterating the VP at a faster rate.



I have read many posts where some people are getting 100K, 200K and 300K on a OEM VP. I wonder what there driving style is as far as EGT and RPM.



Your hard work, time and determination on the subject is very much appreciated.



Rob

 

[rweis]

I am starting to think that the VP is not getting good clean cool air mounted where it is. Looking at the mount it is behind the gear train castings and right up close to the engine block. The air there is off the radiator and intercooler and should be fairly warm. I do not know what the flowing air temp is however. My remote reading thermometer is mounted on the EBC.



Gary's idea of providing cooling air flow directly to the VP body upon shutdown to try to keep the heat soak is good. When I re-route my bilge blower (hopefully this weekend) from trying to suck hot air out from the engine compartment to blowing OAT air on the VP, I think I will program the timer to blow OAT air whenever the ingition voltage is present as well as 60 minutes after shutdown. Maybe getting some decent OAT to the VP underway will help. Of course, maybe not as well.



I am still trying to get about 4* off the VP input fuel temp. I went back and re-read ideas and discussions. I got one of the MOROSO fined aluminum fuel coolers and will mount it down with the RASP (no room up by the radiator, intercooler, I have an ETC and one of my 47RE coolers is up there) where the airflow should be great (I have a front mounted hitch receiver) and see if I can not get this last 4* off the fuel input. The MOROSO cooler has a filter inside of it (which I may or may not use due to flow considerations) but is basically an aluminum tube with mounting legs and with longitudional fins and end plates with gaskets and 4 screws each end. They send 2 @ 1/4 NPT push on barb fittings along with the housing / filter. The 1/4 NPT fitting male DID NOT screw into the end cap 1/4 NPT female end cap at all. I will have to check the accuracy of the threads.



Now that cooler weather is approaching the fuel temp and VP44 temp is not as critical. Fuel flow still is however and therefore the RASP. I am still going to get this fuel system into a steady state system so when hotter weather comes the VP44 survival rate should be significantly higher.



Bob Weis

 

[Texas Diesel]

Bob, I have been reading and keeping up with this thread. Thanks for all the good info. Keep up the good work.

I wonder what there driving style is as far as EGT and RPM.



Rob

Then the clutch people will tell you how hard low RPM driving is on the dampener springs.

 

[rweis]

The MOROSO 41200 fuel cooler is turning into a total screwup.



The end plates that have the threaded ports for 1/4 NPT were not even close for 1/4 NPT. The 1/4 NPT fittings that came with the MOROSO 41200 would not even start to thread into the end plate ports.



OK, so maybe the machineing is a little off. I took my 1/4 NPT pipe tap and was going to rethread the holes for 1/4 NPT. The holes were not even close enough to let the pipe tap start into the hole. OK, look up the drill size for 1/4 NPT and redrill undersize since it is 1/8" aluminum. Redrill undersize then retap for 1/4 NPT, right?, wrong.



After the redrill and the attempt to retap for 1/4 NPT the threads tore out of the 1/8" aluminum. Rendering the end plates useless as they stand. It will take a much thicker (1/2" thick aluminum by 1" round diameter) piece welded to the end plate over the hole to be able to be redrilled and retapped for 1/4 NPT.



I had decided to not use the filter in the MOROSO 41200. I did not know what its flow rate is, and I do not know what level of filtering it provides.



As this approach was falling on its a** I started to look around for other options. On EBay under "finned transmission coolers" by a parts supplier of www.HotzonePerformance.com there are the same finned cooler concept that do not have the filter (which I do not want anyway) and the end caps are tapped for 3/8" NPT for real and they are WELDED on. There are several sizes from 12" to 30" in 6" increments (12,18,24,30) and they come in colors if that is important to you. PAY ATTENTION to the description. The "dual port" ones that the picture shows 2 ports ON THE SAME END have some "dual pass" concept in them. I do not know quite what the concept of "dual pass" is and it looks like the ports are smaller to get 2 ports on the same end. I thought the one port on one end looked stronger and still suited for fuel cooling.



The $$ on the hotzoneperformance coolers is about 1/2 of the MOROSO 41200. In all fairness the hotzoneperformance items do not have a replaceable filter in them.



From what I can see: The MOROSO end caps are screwed into the end of the cooling frame with 4 screws that thread into 4 unique fins. The hotzoneperformance coolers have the end caps welded on (2 less failure points (2 ends)). The MOROSO end plates have an O ring to seal against the end of the cooling frame which I can see as a failure point and eventual leak point (compatiable with diesel?). The hotzoneperformance cooler is welded as stated before.



As it is getting cooler OAT the time frame to figuer out fuel cooling is extended somewhat, but research will continue to go forward. I am going to order one fo the hotzoneperformance coolers and see how it is constructed, quality, and install it if it looks acceptable.



IF the welded end coolers are acceptable they would appear to make good frame mounted coolers, we'll see. Their design is different (ie cylinderical) than the traditional panel design cooler and may offer more mounting choices and less of a total air block if mounted infront of something else.



Bob Weis

 

[rweis]

Mounted the bilge blower by the left front fender well and ducted the fan to the VP44 housing.



I mounted the bilge fan forward fo the left front fender well. Then ducted the fan up to the VP44 body. The duct outlet top is centered on the "christmas tree" that holds a 1/2" harness under the APPS housing. I am using the APPS bottom housing as a plenum. I used some A/C duct foil tape to make sure the air is forced to flow over the top of the VP and if the engine is off then about half the air exits in the 1/2" opening between the gear cover top and the APPS bottom, the other 1/2 of the air exits over the EBC.



Gary and I cruised the internet and found a DIY electronic timer board. Gary built his first and figuered out the "which wire goes where". We both have the boards set to blow air whenever the ignition circuit is engergized to a set time after the ignition circuit is off. Right now I have mine set at 128 minutes after engine shutdown. I have no idea what is optimal, but will tweak the time until I get it toward minimun (I think Gary has his set for 30 minutes, he feels that the engine soak temperatures have leveled off and are starting to fall after 30 minutes)



Starting tommorrow I will collect date for this direction of cooling. I think it may be a fairly good direction. I can force OAT to the VP44 rather than air that has come through the radiator and intercooler and A/C heat exchanger. The OAT can not possibly be that warm even in the hottest day of the summer. I did a very short drive to get fuel tonight and the heat soak temp rise was limited to 10* rather than the normal 50*. However it was a short run and the next couple of days will be the "standard drive" to and from work. I am particularly interested in the afternoon drives as it is still 95* here in FL in the afternoon. Assuming it goes well I will do a longer run 50 miles each way in the afternoon and see how that goes. I hope I am forcing enough air (135 cfm) to keep the VP cool. I can go up to 250 cfm with a bigger blower (4").



Stay tuned, this should be an interesting experiment.



Bob Weis



An 18" finned fuel cooler was ordered last night. Should be here in a couple of days. I am going to mount it after the RASP and on my front hitch frame to ensure it gets maximum air flow (I have an ETC and the nice space right of the radiator is taken up by the transmission cooler).

 

[rweis]

Only 1 morning drive to work (17 miles), but fairly exciting results.



OAT 75*, 2/3 full tank, 17 miles, blower is on whenever ignition is on + 2 hrs after shutdown. Max engine running EBC temp was OAT + 12 (instead of typically + 30), after engine shutdown EBC temp was OAT + 15 (instead of typically +50).



The only drawback so far is the noise from the bilge blower. Can not be heard with engine running, but VERY noisy! after shutdown. That can be dealt with by finding a quieter fan though. Might be on the right track for a change.



One run does not a data trend make, but certainly significantly different.



Bob Weis

 

[GIT-R-DONE]

Bob, do you have any pics of all that you have done ? Set-up of the Rasp system and such?

 

[Gary - K7GLD]

OK - just to clear up a few issues, and coordinate efforts and results, here's an overview of my setup, what I have done on my truck as of this morning:



#ad




Starting at the bottom of the pic is my VP-44 cooling fan with installed shroud to enhance induction of cooler outside ambient air rather than the hotter air surrounding the radiator after engine shutdown - the shroud also seems effective in a small degree of "ram air effect" that provides greater airflow to the upper body of the VP-44 thru the 3 inch aluminum duct seen running at the front of the engine compartment to the VP-44 while the truck is in motion.



That fan is controlled and provided a delayed shutdown after the engine is shut down by the delay system Bob has referred to - mine is set to 128 minutes like Bob's is - that Cummins is a BIG chunk of iron, and heat soak takes a long time to dissipate! You might be able to see the delay box enclosure I am using, it is attached to the top of the underhood fuse/relay box with velcro.



Newly added, is the finned Frantz outer cover I have installed on the Frantz fuel filter - only had it on for one down-the-road trip, too early to have meaningful data to report as to effect on temperature - and you might recall I am currently taking my temperature readings directly off the body of the VP-44 at a point between the fuel port and the top of the VP-44.



I typically see between 10-15 degrees temperature rise above OAT in down-the-road driving. VP-temperatures is clearly DIRECTLY related to fuel flowing thru the VP-44, and as long as fuel flow/PSI is above 15 PSI or so, the VP-44 remains at the above noted temps - but AS SOON AS fuel PSI drops below 15 PSI due to engine load, temps IMMEDIATELY begin to rise - sometimes as much as another 20 degrees or so.



That might not seem like much, but if OAT is at 110 degrees on a hot summer day, plus the "normal" 15 degree rise, and THEN add another 20 degrees of rise due to a hard pull, and all of a sudden, you are at close to 150 degrees at the VP-44!



THEN shut down the engine, get the usual heatsoak - and you have all the ingredients for a VP-44 electronics meltdown!



Our local ambient temps have dropped substantially due to oncoming winter weather - but with my setup, I rarely see above 100 degrees at the VP-44 - barely human body temperature - and the use of the ducted OAT cooling directly to the VP-44 has contained max temps at a nominal 115 degrees or so after engine shutdown.



I *might* still install a small fuel cooler directly ahead of the VP-44 - but that won't be needed until next spring, and maybe not even then depending on additional temp readings in a variety of driving situations.

 

[rweis]

I'm going to borrow a digital camera tonight and get some pics.



My setup is much like Gary's except:



I use a much higher cfm (135 cfm) and mount the fan behind the driver's bumper and forward of the wheel well. Then duct it to the VP44.



Same timing circuit, timing circuit sitting on the power distribution box. Again, Thanks to Gary for figuering out the "which wire goes where" on the timing circuit. He figuered out how to run the fan during engine run, then power the circuit when the engine is shutdown, then after the delay time has expired the WHOLE thing shuts off totally no power. NO SMALL FEAT!



I use much the same concept of indoor outdoor thermometer with the outdoor part mounted on the VP44 EBC. I also measure fuel input temp to the VP44.



I do not have an OEM ff but rather a inline ff down on the frame. I insulated all my fuel feel lines with insulation and A/C foil duct tape (to keep the heat pickup down)



I do a RASP for the lp function. Lp (backup) is on the frame by the tank.



I am getting 2 machined fittings for the OEM tank cannister so I can change the tank cannister to 3/8 full flow lines and no tank return line (my return lines go to the tank vent line).



Other than that it is pretty well stock :-laf (see sig)



Bob Weis

 

[rweis]

The ride home 10/17:



OAT 87* prior to engine start EBC 95*

The EBC temperature came down to 87* then started back up to 97* and stabilized after about 10 miles. Drove the remainder 7 miles 96* - 99* depending on rpm and speed.



Got home and reset the timer to 64 minutes to see what a lesser time would do. The high temp in the first 64 min was 103* and after 64 minutes that was down to 95*. I watched as the timer ran out and the blower stopped. Within 3 minutes the temperature on the EBC was back to 101*. I restarted the timer and the temp came back down to 95 and finally stopped at 88* after another 64 minutes of blower and stabilized at 88*. I'll see how more data stacks up, but it seems that it takes 2 hours of blower to get the Vp EBC down. Notice that it only drops about 8* / hr. Seems like it would drop faster than that, but not so far.



The fact that the max temperature was 99* vs 117* on engine shutdown and 103* as a max vs 130* as a max after heat soak with ??? actual internal temperature. If the cover is 103* the internals can't be much over ? 120*? 130? certainly not as much as 160*.



Obviously will take several more days of collection to see if this is really right. I tow 100 miles in 2 weeks and that will add more data yet.



One thing I find amusing, depending on how you drive you can raise or lower the EBC by a few degrees. Put the transmission in neutral at a stop light and you can lower the EBC 1* - 2* while you are sitting there. As you effect the engine temp based on your driving, you can see the EBC effects.



I think one thing I was thinking about as I watched the max EBC during engine run time and after engine shutdown is that you have to really flood the VP with OAT, and do that right from the start while you are driving through 2 hours after engine shutdown. If you think about it the VP is hidden from air flow behind the front gear cover and only has access to air that comes over the front gear cover between the top of the front cover and the bottom of the APPS cover. The Vacuum pump is below it blocking air and the PS pump on the end of that. On the other side of the VP is of course the 160* engine block. Now they expected to keep that all cool?, how? Oh, yeah, with fuel from the tank canister pickup line well that is shared with the hot return fuel line.



Maybe flooding the VP with OAT has merit.



Bob Weis



I found out tonight that I can run a network with 17 servers, 6 buildings, 700 users but have trouble with a digital camera.

 

[rweis]

Drive to work 10/18 AM



OAT 65* Underhood temp EBC prior to engine start 75*. Engine start the EBC went from under the hood ambient 75* to 70* in about 5 minutes. Then temp started up as VP internals started warming up.



OAT now 70* EBC max'ed out at 82* while engine was running.

Engine shutdown the EBC went to 85* max then after 2 hours of cooling (OAT now at 77*) was at 79*



I am starting to think that providing OAT to the VP in large quanties (right now 135 cfm) right from engine start to xx hours after shutdown is a key. We actually will not know until next summer when the real test will be. I hate to think that a bilge blower will be added to the "road kit"



Drawback is the noise. Sounds exactely like an 120v electric driveway leaf blower (it is a 12v bilge blower). When we go camping might have to park the RV then park the truck up by the check in station?



Bob Weis