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

[rweis]

While I was filling up today I did a little measureing for a fan mounted somewhere between the VP and the ff. To put a fan in there is going to be really tough (ahhhhh, a challenge for someone). So a fan in there may not be the route I try next.



I'll need some time to look at different mounting locations for the ff. It has to be protected, safe, able to be serviced. Maybe not mounting it to the head? Maybe bring the OEM ff more toward the fender. It looks like it has 2 mounting bolts and hangs. Maybe moving it over toward the fender and puting a heat shield behind it. Maybe a removable heat shield for the northern guys so they could remove the heat shield in the winter. I was thinking of something like a Coleman lantern light reflector except tailored to the ff.



To stop the heat transfer between the engine and the aluminum ff I think all you have to do is break the surface contact with like a strip of nylon or something. I could be wrong there. If I am right, then maybe just a strip of a non heat conductor in its present location might help some.



All this will help the running fuel input temperature, but we still have the heat soak potential problem. I have started "poping the hood" for better cooling after shutdown, but you can not do that in every neighborhood.



I have a RACOR 690 back by the tank for primary fuel filtering. I found a fuel filter for diesel 8um. I have to get the flow rate of it. It is an inline filter about 5" long. From a comment about the winter vs summer, I was thinking of the inline for spring to fall, then the OEM ff where it sits for winter. If heat is not a problem, then the OEM ff is not a problem.



You would come off the frame hard line to one hose to the OEM ff. You would have a second hose for long distance or hot weather driving that would bypass the OEM ff and come off the hard line to a inline ff then on to the VP. THIS ASSUMES that you have a way to water seperate (for summer) other than the OEM ff.



Each fit is going to be different and depend on what the owner wants to accomplish. These are ideas that might (or do) work for one but do not necessarily work for someone else except in concept.



Tell me a little more about where you think the OEM ff would go. Brackets are fairly easy to make.



Bob Weis

 

[keimmmo]

I'm thinking about making a bracket mounted on the frame rail under the master cylinder. It would relocate the factory filter almost straight outboard and down a little. There is a big open space there on my truck! It might be a little interesting to get to the water drain, but shouldn't be hard to change the filter element if you don't get crazy about mounting it as low and far out as possible. I plan to plumb everything in rubber hose and eliminate the banjo fittings.



Other benefits are that you still buy factory parts if you plug a filter... not something special that might or might not be available out on the road. It shouldn't effect the warranty since it would still use the factory filter and water separator... and won't effect the engine control computer since everything factory would still function.



It is always interesting to try to put an idea you have in your head into another head. I hope you understand my idea.



Steve

 

[rweis]

I'll take a look in the morning. Might work! Would take care of the heat problem, the air flow problem. Hummmmmmmm.



Use existing holes. How would you back a bolt, or would you use self tappers for the existing hole size?



Graphic Man - What cooling system do you have up your sleeve?



I'll do the heat shield in the stock ff location and we can then compare notes on the three designs.



Bob Weis

 

[keimmmo]

Bob,



I am onto something!!!



Last night I had to make a short trip. When I got back, the fuel filter housing was too hot to keep your hand on.



This afternoon I needed to run some errands. Before I left, I unbolted the filter housing from the motor and tied it up to the brake cylinder with bailing wire. It is a thing of BEAUTY!!! I used a 1/2 inch nut as a spacer under each of the bolts that hold the filter housing to the manifold so I wouldn't have a leak or have to buy different bolts. This is very primitive and temporary, but I figured it would give me the information I want with very little work!



I drove a total of almost 2 hours, with 4 shutdowns. It is about the same temperature as last night, about 80 degrees. I ran the air hard! I left it in gear at stop lights to encourage it to get hot. I was running trans temps of 200*! I wanted to heat soak that filter housing all that I could! When I got home, I raised the hood, and the filter housing was warm to the touch, but I could COMFORTABLY hold it as long as I wanted!!! The side of the head where the filter was mounted was another matter! It was just short of "pealing hide" hot!!!



I WILL be making a bracket and relocating the filter within the next few days! I plan to tap the holes in the frame to mount the bracket. It will require two different bolt sizes, but should work fine. There is enough slack in the factory wiring harness that it is not necessary to extend the wires that go to the filter housing. This is a straight forward, no butchery, no moving parts, and no odd parts modification!



Bob, PLEASE try this if your fuel lines will allow it and get a temperature measurement! I think you will like the results!



Steve

 

[Texas Diesel]

This is an example of learning by keeping your mouth shut. When I first heard of the idea of the FF adding heat to the fuel, I was skeptical but I kept reading. Now it seems very plausable that the FF is picking up heat from the head. Insulating the FF housing sounds like a good idea now



Just like my old dad would say "you can learn more from listening to 10 words than speaking a 1000 words of your own"



I'll just be quiet now and keep reading (and hoping someone posts a picture of how they re-mount their FF).

 

[RClark]

I remember a fin system that was made for oil filters to cool the oil. Would something loke that work on the fuel filter?

 

[nps]

I'll just be quiet now and keep reading (and hoping someone posts a picture of how they re-mount their FF).

May want to consider a summer mount and a winter mount (for those in the colder climates).



I would speculate that some if not all of the fuel heating tendencies were built in by design to warm the fuel up in the winter, before the effects of warm fuel on the VP44 were evident.

 

[Fishin Guide]

Hey Bob,



how about a piece of phenolic or an insulated carb gasket? Heck, even hardwood is a great heat break. This would allow a custom size under the existing mount location between the head and FF.



A simple stainless heat sheild would be easy to fabricate and could use spacers on the FF body under the slied and a really big clamp.



Would take almost no time to make and would be on the cheap for testing purposes. Also, you could ,easure the net effect while leaving the FF in the factory position.



Dave

 

[rweis]

Sounds like a deal to me!



I will find something like a phoenelic temp blocker to the ff mount.



How about a heat shield held on by the same bolts that bolt the ff on. Just make it 12"x12" with a tab for the mount under the two bolts that hold the ff on.



Bob Weis

 

[rweis]

OK, need some help on this.



I went to Home Depot looking for a good insulating simple flat long enough something to put between the ff and the intake manifold to get that part started so I can then take measurements for a couple of days and see what just insulating the ff mount from the intake manifold will do for us.



I found a PVC blank electrical outlet cover ($1. 93). It is totally flat (no ridges), long enough to go under the two mounting bolts, thin (1/8?), and probably needs to be cut in half length wise.



Question?

Do you think the grey electrical box type PVC can / will withstand the heat without melting or going gooey or brittle? If it can, then this will work well, if not, then back to the aisles of ???? (1/8" hard laminate hobby shop plywood, like for model airplanes?). Your ideas, yea, nay?



The exact cover is made by Carlon as a Blank Outlet Cover.



Bob Weis



Oh, also got some (12"x24") 26 gauge sheet metal to fashion a heat shield. However, I want to do this in steps and take readings so guys will know what different options will do for them if they go this route.

 

[keimmmo]

I had a couple of hours to play with the truck this afternoon. I got everything apart and cleaned up. I tapped the holes in the frame. The front one is 5/16. The back one was oval, so I had to drill it out to tap it. There was PLENTY of space for drilling. It wound up 7/16.



I found that there is another hole on the side of the frame close to the front of the starter. I couldn't get a tap between the frame and starter, but I found a self tapping bolt that worked and it too is tapped 5/16.



The mount will be held with three bolts... two on top of the frame and one on the side of the frame. Should be PLENTY strong!



The only fittings I could find to use 3/8 hose on the filter housing are straight fittings. I REALLY need a 90* fitting on the bottom... it would have made life much easier! I have had that filter housing in the hole every way except upside-down... and I WOULD mount it that way if I thought it would work!!! It looks like I will wind up mounting it rotated 90* with the inlet facing the outer fender. Seems to be the best option. It sure will make it easy to hook up the electrical plugs!



There is an electric fuel heater in the housing. I am considering unhooking it for hot weather and hooking it up for cold weather. I do NOT see cold weather at all down here... 30* would be BITTER cold. However, I do get up to Illinois every April and October and can see some chilly weather. If I use an anti-gel fuel additive when it gets cold, I feel confident there will be enough heat from the heater and the return fuel from the VP to avoid problems. I also plan to cover the fuel cooler with cardboard in cold weather.



I'll keep you posted as I progress. I will be doing it as I have time, so it might be a couple of days. I REALLY wish I had a way to measure the temperatures!!!



Bob, if your fuel lines will allow it, I REALLY recommend you hang the filter housing from some bailing wire like I did to get a measure on the temperature difference! I think it will be considerable!



Steve

 

[GIT-R-DONE]

Why couldnt you just use a flat piece of steel, that would bolt onto the original ff holes and bring it out toward the fender 12" or whatever would be the best distance you could get? Bolt on the ff to the steel (other end). I highly doubt that there would be enough residual heat travel out the steel and get to the ff. Just thinking out loud here... .

 

[rweis]

What about rotational torque of the weight of the ff?

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Someone stole ALL my hand tools out of the back of my truck last night so I am "stopped in the water" until it goes thorugh insurance etc etc. Probably several weeks.

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The ff canister has weight, the weight of the fluid, and the weight of the hose connections all add up X the moment arm of the piece of steel.



I would not want to strip a bolt out of the intake manifold either.



Bob Weis

 

[keimmmo]

Yes, I thought about just extending the filter housing away from the motor. But, the more I thought about it it seemed like it would solve one problem and creat several new ones. I decided against it.



I am running a fuel cooler after the filter and before the VP. With mounting the filter on the frame it eliminates going from lines mounted on the frame to the motor back to the frame and back to the motor. This way, there will be only one connection between the frame and the motor. I also think it will give the best cooling of the fuel.



Grandpa always said, "Time will tell. " We will see what time has to say.



Steve

 

[RClark]

What about using longer bolts and spacers to move the filter away from the engine and allow more air circulation around it?

 

[Fishin Guide]

Bob,



just grab a few pieces of thin plywood like 1/4" and sandwich your foam between it. Say, 3 layers of plywood and 2 thin strips of foam. Gule it together or just mount it under the exisiting mount.



Actually, a particleboard or mdf product would be better yet for compression strength. Then you can retorque the new longer bolts.



This is a very effective heat break! Back in the old days, it was used as a carb spacer. Stopped fuel boiling in the well.



Dave

 

[Hohn]

OK, I guess I need to repeat myself for a third time:



Fuel coolers need to be AFTER THE engine, on the RETURN SIDE. Simply put, a cooler works best when there is maximum temperature differential.



When you put the cooler on the SUPPLY side, it's just as likely that your cooler will HEAT the fuel as cool it-- ESPECIALLY in hot weather. Remember, a cooler is dumb. It just follows the laws of thermodynamics. Specifically, that energy flows from hot to cool, never the opposite. So if your fuel is coming in at 100° and underhood temp is 130°, then you have HEATED your fuel, NOT COOLED IT!



Second, why would you put a cooler under the hood where the air is hotter? Why not mount it remotely back where it operates in cooler air? Also, the length of fuel lines that you run to the cooler would also serve to provide a minor cooling effect.



So, here's the long and short of it:



Supply side cooler: hotter air, cooler fuel. Fuel tends to be heated or minimally cooled.



Return side (proper side) cooler: cooler air, hotter fuel, fuel will be cooled with maximum effectiveness.



Sorry fellas-- I don't know how to make it any clearer that the proper location for a fuel cooler (if in fact, you want cooler fuel temps in hopes of keeping the VP alive), is on the RETURN SIDE!!

 

[Hohn]

I would speculate that some if not all of the fuel heating tendencies were built in by design to warm the fuel up in the winter, before the effects of warm fuel on the VP44 were evident.

Are they evident? Do we know that the warmer fuel is responsible for VP failures??



I'd think that with an electric fuel heater, one could insulate the FF housing without increasing the likelihood of fuel gel-up.



Besides, if you gel up your fuel filter, it's going to happen when the engine is cold-- LONG before the engine has generated enough heat to warm the FF hsng and conceivably warm up the fuel.





I think it's pretty safe to say that the FF hsng arrangement was NOT designed with some kind of anti-gel property, as it simply wouldn't have the effect in reality.



jlh

 

[CORed]

Easy Justin,



I (we) hear you and, at first, your theory made sense. But with the research a few guys on here have been doing (thank you all), having a cooler on the return side is basically MUTE. The fuel is heated up again in the FF so any cooling you accomplished on the return side is negated.



And secondly, the cooler that is being talked about and employed between the FF and the VP will be located behind the front grill where it will get direct outside air, not under the hood where, as you rightly say, the temps are much hotter. I was not sure you realized that. It sounded from your post like you thought maybe the cooler was going to be placed in the engine compartment itself.



So maybe during the first couple minutes of driving, yes, a cooler mounted between the FF and the VP on the front of the radiator may be ADDING heat to the fuel... especially if it is hot out. But after those few minutes, it will be cooling the fuel since the OAT will most likely be less than the temp of the fuel. And from some guys' estimates, the FF is making the fuel so much hotter, that a cooler setup on the supply side WILL be cooling the fuel substantially before hitting the VP... where it can do some good and accomplish the goal of this thread / experimentation. And if the outside temps are even more reasonable (cooler), you will REALLY be cooling the fuel just before it is to be used by the VP.



Again, any cooling you did on the return side just made your plastic fuel tank cooler which does nothing to help the VP44 when the fuel is heated back up again in the FF.



I (and I believe most) will continue to respect your opinions and appreciate them. But this post sounded like you are everyone's daddy and YOUR way is the ONLY way.



Keep the data coming guys!



Steve

 

[Texas Diesel]

I'm going to have to side with Honn on this one. The crucial data would be the *FUEL* temp rise between inlet of the FF and the outlet of the FF. The temp of the FF can is interesting but the temp of the FUEL is the missing ingredient.



Plus the FF is going to raise the temp of the fuel a consistant amount. In other words, say the FF housing caused a FUEL temp rise of 25F. 100F in and 125F out. 75F in and 100F out. Without a return fuel cooler you would be dumping 150F (my own estimate) fuel into the tank. With my return fuel cooler I am dumping 100F fuel into the tank.



So, tank temp + FF rise = 150 + 25 = 175F VP inlet, if I use an aftercooler then tank temp + FF rise = 100 + 25 = 125F at the VP inlet



The variable here is the effectivness of a FF-VP cooler. Again what Honn said, the greater the beginning temp the GREATER the heat rejection of the cooler (for a given size cooler).



If I am not mistaken the FF heater activates at a fuel temp of 75F.



The only REAL way to settle this is to take 1 hour drive and measure FUEL temp and then move the cooler and repeat the 1 hour drive and see which one yields lower VP inlet temp.



Having said all that, what was the question? :-laf