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

[AKAMAC]

Bob, here is a "degree" symbol to use in your future posts.



125 ° F



Just copy it to note pad and "ctrl v" it where needed.

Keep the info coming, sounds like you are making progress on this. Mike

 

[rweis]

Thanks °



New fan data:



Right now I am running the 4" bilge blower 230cfm at full power during engine run and for 128 minutes after shutdown. The 4" has a MUCH lower pitch "whine" and is about the same noise at full power as the 3" was at 2/3 power.



The EBC had been operating at OAT +15° (normal running conditions). Now the EBC seems maybe -2° cooler (normal running conditions). Only 3 runs at this point and need more data to confirm.



The max temp after shutdown had been shutdown EBC +5°. Still is same +5°, no apparant change, but more data needed.



The temp profile after shutdown tonight was:

Engine fully warmed up, stop and go in town driving for 45 minutes,



shutdown EBC 77° OAT 71° battery 13. 1v

max temp after shutdown EBC 82°



min temp after shutdown EBC 70° (fan runs 128 minutes) OAT 69° (about the same 6° per hour drop in EBC temp as 3" 130cfm full power was, but a LOT less high pitch whine) battery 12. 6v



temp after 4 hours after shutdown EBC 80° OAT 67° (the under hood metal mass still warm after 4 hours after shut down)



I am going to try to use a standard 2 hour and 4 hour check point after engine shutdown for temperatures so we have some sort of standard yard stick to go by.



Bob Weis

 

[Texas Diesel]

Here is my stupid contribution:



Back in my overclocking days (runnning a CPU faster than rated) we could locate a small 2"x2" heatsink to epoxy to the CPU. The heatsink had a water jacket inside through which we ran ice water. I seem to remember these heatsinks being available in different sizes. There were very quiet, very small water pumps available too. Putting this all together with a small transmission cooler and you could water cool the VP EB cover even while driving. Operation would be infinately more efficient than a fan alone and VERY quiet. Add some sort of collant overflow (including antifreeze) and you would have a system that could transport some serious heat.



Has anyone that has replaced a VP commented on the feasibility of an insulating gasket between the VP and timing cover? First thought is no because of timing gear alignmen.



The surface area of the transmission cooler would be enough even when stopped I would suspect.

 

[rweis]

Faster driving speeds:



I did the 70 mph drive today. EBC went to OAT(75°) + 25°=100°



Fuel input temp was 90° (BTW tank is almost empty - last 1/8 before fuel low light comes on. Wanted to do some testing in this arena also. )



When I got home I checked the temps a couple of times. Shutdown time 1645. Fan is set to 128 minutes full power.



1645 OAT 75°, fuel input 90°, EBC 99°



1655 EBC is starting to begin to reduce in temperature (very slowly)



1745 OAT 74°, EBC 92° (Same 6° per hour as we have seen before)



1845 OAT 72°, EBC 85° same comment as above



1945 OAT 71°, EBC 97° - SAY WHAT? We're back to where we started 2 hours ago! Sort of, at least the engine has been cooling. The fan shut off at 1845. This reading had a high of 99° (went from 85° with fan, fan shut down, temp went to 99° and started back down to 97°) and actual of 97°, and a low of 85° (when the fan shut off)



2045 OAT 70°, EBC 96° at least it still going down without assistance



Sooooo, even after you have cooled the VP44 for 2 hours, there can still be a reheating by latent engine heat. Now doesn't that just make it fun?



Is 2 hours enough?, maybe not. What about battery amperage draw per hour? What would have happened if the OAT was 100°? And we wonder why the VP44 has EB temperature problems?



Edit added - The amperage draw is 2. 95 amps.



Texas Diesel - I remember the Apple II GS has a refridgerator card to help cool the CPU. It was not very popular (not sure why, maybe cost). I think it had some sort of a solid state cooler built on it. I am really looking forward to your testing this approach. A better "mouse trap" will certainly be appreciated.



Bob Weis

 

[Texas Diesel]

Bob, the Apple you are referring to used Peltier Juncitons to cool the CPU. Very expensive and didnt move much heat. The water cooled doo dads will move tons of heat.



I'll look around for info on them when I get a little spare time.

 

[keimmmo]

Glad to see the search for cooling the VP continues. I just returned from a 10,000 mile trip... over 4,000 towing. I am pleased with my system the way it is. Yes, more could be done to further cool the VP, but it runs so much cooler than stock that I just don't see the reason! The fuel cooler tank that returns the fuel to the VP is about the same temp as the front bumper... no matter the OAT! The poor VP lived a much harder life before than now!



I stopped by and had a short but enjoyable visit with Texas Diesel on the way home. He took a few pictures of my home made fuel cooler. I hope I can get him to post a few pictures for me.



I will be starting a new thread in the next day or two to tell about what I learned on my trip. Don't get me wrong! You guys are great! I am just thinking about starting something new so the ones who are just getting into the project will not have to wade through 350 posts to get up to speed!



More to follow...



Steve Keim

 

[rweis]

Looking forward to your post. Additional ideas and results are always a good idea. A new thread is probably a good idea, this one is getting long in the tooth.



I am especially interested in the OAT's you encountered and how the front mounted cooler did. I still can not get the input fuel down to OAT. Maybe moving my cooler up front.



The under the bed cooler even with a fan is not getting it done the way I want it. I have an ETC and not a lot of free space up front that does not block something else (transmission cooler, intercooler, etc).



I'm very interested in your ideas and results.



Bob Weis

 

[Texas Diesel]

Ok Steve, I can take a hint :-laf

 

[Texas Diesel]

Steve, you can explain the pics.



How was the smoked chicken?

 

[rweis]

Now, that is thinking outside the box Oo. I like the concept. Definitely food for thought!



Bob Weis

 

[keimmmo]

Thanks for the help Texas Diesel! And, the chicken was great!



I had the problem that any commercial made cooler was too thick to fit in front of the radiator and would block air flow. Now, I realize that running plain tubes like I am is not the ideal for cooling, but with enough tube length, it will still work. Besides, we are looking for only a few degrees... not a MAJOR difference!



I built the cooler using 1/2 ID rigid copper tubing for the tanks and 3/8 OD tubing for the pass tubes. The tank on the driver's side is really two short tanks joined by a piece of steel for structural strength. I made tabs that I brazed to the tanks to mount the cooler to existing bolts and holes in the front end. The fuel flows through 4 tubes as it crosses to the passenger side and returns through another 4 tubes.



A concern with a cooler is the added length of line that can reduce fuel pressure. When I first made the cooler, I ran an automotive inline fuel filter in the line just before the VP to catch any crud left inside the cooler from the brazing. When I removed it after a couple of thousand miles, the pressure was 4 psi GREATER than when using the original fuel line and drilled out banjo fittings between the filter housing and VP!!!



I run the fuel into the top and out the bottom... and cooler works best that way. However, that causes a big air bubble in the top of the cooler. I installed a drain valve out of an old diesel fuel filter in the top of the passenber side tank so I can "burp" the system.



While I have no way of actually measuring the temperatures, on a hot day, the tank at the outlet of the cooler feels about the same as the front bumper. It is DEFINITELY much cooler than the inlet!!!



My goal never was to cool the VP as much as possible... just make it's life easier. I was really after the fuel economy more than anything. I gained right at 1 mpg towing and 2 mpg empty. I'll give more of my tests and results later. The biggest strong point of my system is that there are NO moving parts!!! It is something you can just install and forget!



More later in a new thread.



Steve Keim

 

[rweis]

Well I towed this weekend 100 miles one way.



Observations:

First point:

I found out that puting anything BEFORE the lp (or lp system whatever you have) is NOT smart. I had a return fuel cooler and changed it to a pre lp fuel cooler. Well I had some air leaks and since the lp systems are SUCTION systems I sucked a lot of air at the higher power settings. Without towing (traveling light and empty) all had been doing well, with towing (heavy and high fuel demand) it sucked to say the least. I will change it all to fuel return (ie under pressure) or after the lp where pressure leaks would be obvious.



I was glad I had the RV, but sure ****** folks off at 50 mph which was the max fuel flow (speed) that held good pressure. I deduced that at higher sucking on the RASP it started to get air in the system as evidenced by sometimes rapid drop in psi where the carter lp would hold the psi to 10. I could go in and redo fitings etc, but to be safe I am going to go to a positive pressure location for the coolers.



Moral to the story - make sure you have a good solid (no air) feed to the lp system so it can then do its's job of developing good pressure to the VP.



Second point.

So far towing it seems like VP fuel input is OAT + 30 (empty VP fuel input is OAT +15). The fuel heaters come on at 50 I think. For deep south guys like myself that also put an anti gell (Stanadyne or etc) in every tank the fuel heater is not a factor. I did take out the OEM ff completely and put in an inline ff. I think I will do like Steve Keim and just relocate it to the frame and keep the fuel heater connected. I even think I can use the total aluminum block of the OEM ff to help get rid of some fuel temp if it is mounted in the ram air slipstream.



I will continue experimenting to get the fuel input to the VP more like OAT (when you want it, a ball valve ?). The VP EBC ran at OAT + 30 degrees also. (4" bilge blower running all the time of engine run + 128 minutes after engine shutdown). I am trying to protect the VP when OAT = 100 degrees.



Third point.

You need some sort of powered fuel cooling when you are crawlin through traffic. Ram air cooling is good if you are going to be running 50 mph + for long distances. Probably a mix of the two is a good idea.



Well, happy holidays and I will report back after I make the changes and do another longer tow.



Bob Weis

 

[keimmmo]

Someone replied on my thread to my question of why my fuel ecomony increased with the fuel cooler. He said there is a fuel temp sensor inside the VP... and he can read the internal temp with a Snap-on scanner tool. Bob, I have no way of getting access to one down here, but that might produce some serious data for INTERNAL VP temps for you!!!



I see merit in cooling the return fuel, but I do not like having a motor that can fail. Also, there is no way the under the truck air is as cool as what enters the grill area. I went for a major improvement without a lot of investment or extra moving parts. That is why I have my cooler in front of the AC condenser.



Bob, do you have a torch? Can you braze? If so, you can build a cooler like mine for less than it will cost you to buy one! You have tried about everything else! It would be interesting to see how my system compares since you can measure temps. If you decide to build a cooler, I will give you the dimensions and tips from my experience building mine.



Steve Keim

 

[rweis]

Yes I have access to a torch and like your idea of the upfront cooler that does not block a lot of air. I have experimented a good bit and want to build a better mousetrap before it gets to 100 degrees OAT next summer.



I would be interested in your lessons learned for sure. I will build your version and see what happens. I am also going to look for a place for the OEM ff. Maybe I can find a place it can help lose heat.



When I was towing this weekend I know I am not taking out as much temperature as the Vp is puting in. I watch the input fuel temp rise and rise and rise and finally see it stop at about OAT + 30 degrees (I think that the VP and injectors add about 15 degrees (to the VP input fuel temp) empty and I do not know how much loaded, I'm guessing maybe 20 - 25 degrees). Now that is flat land towing (not mountains), 50 mph (ie not fast), 5er weighs 13k (not a WHOLE lot) and wonder what is happening to guys that tow HEAVY in mountains and much faster (65 - 75 mph).



I have a conference this week and wil not be able to do anything until next week.



Thanks for the experimentation and inputs,



I'll try to find out what the Snapon scanner tool is or does or where and how to find or borrow one.



Bob Weis

 

[keimmmo]

HOW TO BUILD A FUEL COOLER (See pics on posts #348 & #349)



My cooler is made of 1/2 rigid copper tubing for the tanks and 3/8 flexible for the cross tubes. The cooler is 16 1/2 inches tall and 26 inches wide. It would be possible to go taller and/or add more tubes... just be careful that the tubes do not interefere with the studs that mount the AC condenser or trans cooler! To make it any wider would require a different mounting system than I have used.



You can buy the tubing any place where plumbing supplies are sold. I brazed all joints to assure good strength. Lightly sand all areas to be brazed... cleaning the copper makes it easier to braze. Make sure your joints seal and do not have leaks!!! Diesel will find the smallest imperfection and LEAK!!!



The passenger side tank is 16 1/2 inches tall. The driver side tank is made of two pieces 7 3/4 inches long with a 1 1/2 inch space between them... a total of 17 inches long. The pass tubes are about 25 inches long... I used 8 of them.



I recommend starting with the driver side tank. Plug the ends that go together in the center and braze a brace on them to make one long piece out of the two. I recommend plugging the ends in the middle first since it is very difficult to cap them after brazing the brace between the two pieces! Trying to work with two separate pieces is fairly difficult. If they are not braced together the finished cooler will be weak. I brazed oil galley (expansion) plugs that I had on hand onto the ends to make the plugs. Do not plug the other open ends at this time. It will be easier to clean out the inside later with the ends open! I put the brace between the tanks on the front of the tubes... but it has to be a small piece or it will hit the front bumper! Brazing it on the outside will block air flow. Brazing it on the inside is not an option since it will make it impossible to put in the pass tubes.



Note that the cooler needs to be mounted high enough that the upper inlet hose will clear the top of the trans cooler. It also makes it clear better and is easier to install the hose if you angle it slightly toward the rear! The inlet and outlet are just pieces of 3/8 tubing with a very slight flair on the end to better hold the hose.



Present the drivers side tank to the front of the trans cooler. Mark where you plan to put the cross tubes... making sure they will not hit the studs that mount the condenser and trans cooler! Drill the holes for the inlet and pass tubes with a 3/8 bit. The outlet can be any place on the lower tank... pointed straight outboard. I have mine in about the middle of the tank. Toward the bottom would also be fine. DO NOT put it in line with a pass tube!!! It will be VERY DIFFICULT to position both tubes so they will flow well!!!



Lay the passenger side tank beside the driver side tank and mark where to drill the holes for the pass tubes. Drill the holes.



I recommend brazing in the top and bottom pass tubes first. That gives you a frame to work with for brazing the rest of the tubes. It is also the easiest way to get everything square! Braze in all the pass tubes, the inlet and outlet.



You need four sturdy pieces of strap steel for mounting braces. Place the cooler in front of the AC condenser and mark where to locate the mounts. I used the two studs/nuts that mount the condenser as mounting points.



With the drivers side mounts in place, the cooler will hang in place so you can make and install the passenger side mounts. Use the holes in the AC condenser as mounting points. If you remove one of the screws in a factory mount you can see what size screw you need. I used "poor man's Loctite" (silicone) to keep the small screws from vibrating loose.



At this point you can clean the inside of the tanks the best you can and plug all open tank ends.



For the "burp valve" on the top of the passenger side tank I just built up several layers of braze over the expansion plug. Drill out and tap it for the valve... probably 1/8 NPT. My valve is from an old fuel filter. BE SURE the valve is rated for fuel!!! Some valves from radiators for example have rubber seals that will swell when exposed to fuel and leak!!!



When I first installed the cooler, I added a cheap 3/8 inline automotive fuel filter between the cooler and fuel pressure port. You WILL have some burrs and welding crud in the cooler that could damage the VP!!! I removed the filter after a couple of thousand miles and hooked the cooler directly to the VP.



This will give a good idea of how to make the cooler. Feel free to ask questions if there is something you do not understand.



Steve Keim

 

[rweis]

I spent the last several hours re-reading VP-44 threads.



One of the side benefits I think of cooler fuel is the lubricity of the fuel will not thin as much on the VP44 internals when lubrication is at a minimum.



Of course there are the additive discussions, but whatever your preference, cooler fuel should hold its lubrication characteristics better than hot fuel.



Bob Weis

 

[keimmmo]

I agree totally! I have felt from the start that hot fuel would not lubricate like cool fuel!



Steve Keim

 

[Gary - K7GLD]

For the umteenth time, I've heard the old "heat doesn't REALLY hurt the VP-44 electronics, besides, if heat and control boards WAS an issue, why don't ECM's fail too?"



Number one, Bosch (regardless of what OTHER critics suggest. . ) has seen fit to upgrade the VP control boards, according to some of their reps, because excessive heat was causing premature board failures. Those board mods are now standard upgrades on all reconditiond VP-44 for the last 2 years.



Critics may debate the finer points of that all you like, many of us involved in these extensive tests and expirements are FULLY convinced of the damaging effects of excessive heat on circuit boards and related components.



It's also worth pointing out that solid-state devices HATE radical swings in operating temps - it causes unwelcome expansion/contraction of delicate internal connections that eventually fatigue and either lose contact, or become intermittant.



Number 2, ECMs/PCMs *DO* fail - perhaps not as often as VP-44's, but they DO fail, as has been reported on this board a number of times!



A few samples? SURE!



https://www.turbodieselregister.com/forums/showthread.php?t=129076&highlight=ECM+failed



https://www.turbodieselregister.com/forums/showthread.php?t=129821&highlight=bad+ECM



https://www.turbodieselregister.com/forums/showthread.php?t=86065&highlight=bad+ECM



https://www.turbodieselregister.com/forums/showthread.php?t=85479&highlight=bad+ECM



BUT, comparing ECMs to VP boards is apples/oranges - they are made by different manufacturers to different specifications and tolerances, perform different functions, and are mounted in different locations and exposed to different airflow characteristics.



Number 3, I have made enough temp runs with my remote temp sensor attached to my VP-44 that I have now removed it, and moved it over to the backside of the ECM, between it and the engine block for another series of temperature monitoring...



Any critics wanna go out on a limb, and start with predictions as to actual ECM temperature swings as compared to the VP-44? :-laf :-laf

 

[keimmmo]

Gary,



What on earth are you ranting about now? When was it last mentioned on this thread about the effect of fuel temps on the electronics?



Hey, some of the guys up north have a pretty wide operating temp range right now! I would say their coolant temps run from about -40* up to 195*!!! As though that has anything to do with the subject of this thread.



Steve Keim

 

[Gary - K7GLD]

"What on earth are you ranting about now? When was it last mentioned on this thread about the effect of fuel temps on the electronics?"



UMMmmm - excuse me?



What "rant" and where did I say the comments I addressed came from THIS thread - altho' I do seem to recall some to that effect here as well...



I *do* get to other threads and boards, and figured in light of low activity on this thread, I'd make the comments I did - sorry to have offended you and ruffle you feathers...



Cheers to the good guys, to the rest...