Fuel Delivery Redesign: "Project Number Two"

[rbattelle]

Lightman,



I certainly take no offense to your comments, and I respect your opinions (that's why I posted this in the first place, so people can offer their opinions). I did look at the Stanadyne (another outstanding unit) but forgot to list it. I basically eliminated it because it's easier to get Fleetguard filters than Stanadyne filters around here. And, honestly, once I saw that Davco model I was enamored with it!



You are absolutely correct when you say I could just plumb in a 2-micron filter in series and add a pusher pump. However, I am rather a bit obsessed and I love "big" construction projects. So, I decided I wanted to redesign the entire fuel delivery system to use "standard" fittings like NPT and AN rather than the stock components which are basically dealer-only parts. With this setup everything is industry standard and hence available worldwide with ease.



Finally, it's my hope that the system turns out great and I "inspire" others to press on with similar modifications. I am of the opinion that what comes from the factory is meerly a "suggestion" of one possible way of doing things. In particular, it's usually an example of the "cheapest" way of doing things. Since I'm unconstrained by bean counters, I can build a fuel delivery system fit for an F-16!

 

[JHardwick]

No offense but it seems to me that you've way overcomplicated the issue.

He's an engineer



no personal offense Ryan :-laf

 

[rbattelle]

"If it ain't broke, fix it 'till it is. "



[no offense taken]

 

[JHardwick]

I've made fittings for the F-16 and plenty of parts for GE Aerospace ... ... ..... Aeroquip leads the way in -AN stuff and it trickled down to the local racer. You can buy Russell and some other knock-offs, but Areoquip and their push loc -AN stuff is superb ... ... ... ... ... . again, if you assemble it right!

 

[JHardwick]

"If it ain't broke, fix it 'till it is. "



[no offense taken]

:-laf :-laf :-laf :-laf



that HAS to be one of them engineer inside jokes

 

[Gary - K7GLD]

I'm surprised at the lack of expressed concern over mounting that much mass to the engine itself - users of Frantz filters - a MUCH smaller and lighter unit - have had brackets fracture doing that very thing!



It can undoubtedly be done - but LOTS of engineering will likely be needed for reliable long-term installation and use...



Good luck!

 

[rbattelle]

I'm surprised at the lack of expressed concern over mounting that much mass to the engine itself

Mass of that Davco unit full of fuel should be less than, say, an A/C compressor. I don't see much problem building a mounting system that won't fracture. It just takes some time and effort, and I refuse to fail for lack of either of those.

 

[csutton7]

Aeromotive pumps have inlet sizes that they recommend and they desire a pre filter also--a regulator will most likely be needed---my system is triggered using the OEM pump wire to fire up a 30amp relay to provide power to the A1000 pump--I'm also 100% gravity fed--which is important with any electric fuel pump(they are pushers, not suckers--our factory systems are not gravity fed and neither will any using the OEM pickup tube--I punched a hole in the bottom of my tank, but if you're using an in-bed tank you could become 100% gravity fed without to much work--my system also uses a Racor heater/water sensor/filter---of course my truck is a '99 also--good luck---chris

 

[Boonieman]

This looks like a well thought out project for sure. I'm curious; did you consider installing a second fuel pressure gauge, say at connection #5? I'm just thinking that it would be a nice touch to be able to monitor DP across the entire system. It may help indicate fouling earlier than a single pressure reading at point #2. Anyway, the whole deal sure sparks my imagination.



Danny

 

[rbattelle]

I was just reading Aeromotive's website and as CSutton suggests they highly recommend a pre-pump filter. However, they mandate that the pre filter can be NO FINER than 100 micron. They carry such filters with 100 stainless screens.



Doing some more reading in the FAQ's over at Aeromotive is making me rethink my choice of fuel pump. Aeromotive points out (as others here have) that the massive volume their pumps generate will mostly be bypassed and sent back to the tank. The restrictive nature of the stock fuel pickups in the stock tank makes the high volume pump somewhat dangerous. Copied from Aeromotives tech tips:



Common problems associated with stock fuel tanks and fabricated pickups are pump cavitation, vapor lock, varying fuel pressure, exaggerated pump wear and lean conditions during both low and high loads. Note: Unlike a carbureted engine, any loss of fuel supply at the in-tank- pickup will immediately result in a loss of fuel volume and pressure at the EFI injector resulting in a momentary lean condition and possible engine damage.



I'm thinking a much lower volume pump would be wiser. I'll have to do some research to find an appropriate one... any suggestions?

 

[rbattelle]

Update

Here's a pic of where I want to locate the Davco unit. With it in this position, it's very tight but you can still access the power steering dipstick without being a contortionist. The P/S hoses and upper radiator hose will need to be either wire tied out of the way or wrapped in metal to prevent chaffing. I'll start working on a mounting bracket this evening. It'll bolt up to the engine.



#ad




I am still researching an appropriate fuel pump...



-Ryan

 

[rbattelle]

The search continues

Today I read this enormous thread.



As I see it, you want a fuel pump that will deliver exactly what the CP-3 wants to see with minimal need for bypass return. So, what does the CP-3 want to see? All I know is it wants a minimum of 38 GPH at the inlet. The pressure required for that flow rate depends on the inside diamater of the Weber fitting that enters the CP-3.



It seems that CSutton has the most time-proven system, using the Aeromotive street rod pump and a gravity-feed system. I want to use the stock fuel pickup instead of gravity feed. I don't think there's any data to indicate whether his Aeromotive lasted over 3 years in service due to the gravity feed design or due to the quality of the pump. Anyway, I think I've narrowed it down to either the Carter 4601HP (which is what the DD pusher is) or the Aeromotive.



When I find out what the ID is for that Weber fitting I'll do some rough calculations to see what pressure I need to get 38 GPH...

 

[Gary - K7GLD]

"our factory systems are not gravity fed and neither will any using the OEM pickup tube"



WELL, Chris - tell ya what...



IF you don't think there is positive fuel pressure in the stock line back close to the tank down along the frame, try cutting that line when there's fuel in the tank and see what happens!



IF you could actually guage the PSI at that point as compared to your bottom outlet, I'd bet any difference would be quite negligible - the siphoning flow from the top route as compared to the bottom flow at the same relative height will be absolutely the SAME - all other factors such as line size, being equal...

 

[rbattelle]

Update

Well, I do continue to work on this at least a few days a week. I have acquired most of the electrical components required to wire up the system, including environmentally sealed Amphenol MIL-Spec circular connectors, 35A relays, LEDs, and some project boxes. There will be 2 boxes: one under the hood that will house the necessary relay(s) and serve as the main junction box; another in the cab drilled out and fitted with switches, LEDs, and a fuel pressure gauge.



I have decided on the Aeromotive street rod fuel pump and regulator, based on the excellent experience CSutton has had with it. I will also run their fuel pressure regulator, probably at 14 psi.



My biggest problem at the moment is trying to find a convenient place to mount that monster Davco filter. I fabricated mounts that could bolt it to the intake manifold just in front of the intake horn thereby positioning it in the location pictured above. There are 2 problems with this. First, it's not immediately clear whether there's enough clearance with the hood (will be very frightening to start the truck up that first time... not sure how much that engine moves, but I suspect its a lot). Second, the unit weighs 15 lb when full of diesel fuel and I have some fear that over time that could bend or break the intake manifold where it's bolted in. That would be bad.



I've been all over and under that truck trying to locate somewhere convenient to put this thing, and it's proving difficult. It's largest dimensions are 16. 1" tall by roughly 7" diameter. You'd think it wouldn't be a problem in a truck this big, but there's a lot of stuff under that hood! Tonight I even started to consider moving the washer fluid reservoir and the fuse box and putting it there. Problem is, where do I put the fuse box? I don't want to have to extend the wiring for it!



Suggestions are quite welcome!

 

[Roger rodbolt]

rbattelle,

The intake mounting you mentioned is actually a reinforced part of the cast iron head. I've cut that casting off, through the tapped bolt holes when converting a VP-44 to a P-7100 and it's beefy. You should be able to mount the mega filter there and brace it back to the intake bolts (if necessary) and be plenty strong if you still want to use it. I might mention that if you use a prefilter for your pusher pump, your forward fuel heater(s) will be of no (very liittle?) value as fuel waxing or gelling will occur at the first filter. Also if high fuel filtration is a priority it would be benefical to put the 2 micron filter in front of the pusher but behind the return regulator. That way, like the AirDog, you would "polish" the fuel by filtering a tank one or twice before it ever saw the injectors. I am curious as to why you want to retain the stock filter and can? Because the AirDog has a good selection of filtration I've not researched it but I suspect someone makes a high micron filter for the factory can and that would simply your system by eliminating the big unit. Larry

 

[rbattelle]

Roger,



Well, I want to retain the stock filter canister (and filter) because it already has a 300W integrated heater, which should allow me to run my final filter without a heater if I so desire. Besides, there's really no such thing as "too much" filtration. "Industry Standard" filtration would dictate a step-down filter arrangement rather than a single 2-micron filter. At least, that's what I've read. I'm not a filter expert by any means.



Given the issues I've been having with that Davco unit I'm now considering buying a Stanadyne Fuel Manager FM-100 filter head instead. I'm going to talk to Scheid Diesel today and see what they can do for me.

 

[mhenon]

I think it's time to move those batteries someplace else. That will give you all the room you need to play around under the hood!!

Mike

 

[rbattelle]

I had also considered moving the batteries (or at least one of them), but then I have to find a place to put the batteries, which seems like an even bigger problem than the Davco. I'd probably have to put them in the bed and run welding cable all the way back there.



I just got off the phone with Scheid Diesel in Terre Haute (not far from here). They offered a small TDR discount on an FM-100 filter assembly so I went for it. At around $52 plus shipping I can't really lose. I haven't decided what to do with the Davco... whether to sell it on Ebay or just keep it in case I decide to try it out in the future. Once nice thing about the Stanadyne system is they actually have plots of filter efficiency vs. particle size on their website. Their 2-micron is 99% efficient at 45 GPH.



Apparently, I have learned a valuable ($200) lesson: size must be carefully considered when setting up your filtration system. Seems obvious, but at the time I just assumed there would be plenty of room for the monster Davco unit.



Only problem with the FM-100 is it's advertised to flow 80 GPH max. Regulated to 14 psi, my Aeromotive pump will flow 100 GPH. I have heard the restriction in the Stanadyne has nothing to do with the filter and everything to do with the size of the inlet/outlet ports (I got 3/8 NPT). Anyone know what happens when you try to run 100 GPH through an 80 GPH filter?



-Ryan

 

[rbattelle]

Update

I've begun wiring things up for the electrical system. Here's a picture of the under-hood junction box (which is still under construction):



#ad




As I mentioned earlier, I'm using all Amphenol connectors. There are inputs for the battery and the ECM and an output for the new fuel pump. On the side there's a 17-pin connector that will feed the in-cab station. I don't need all 17 pins now, so there will be room for future expansion. I'm also going to run LED's for the grid heaters via this box. I think when all the circuits are connected I will have 6 or 7 extra pins for the future. There is a TON of soldering that still has to be done.



I got the new Stanadyne filter last week. Attached is a photo comparison between the Davco and the Fuel Manager... the Davco could eat the Stanadyne for breakfast. This thing is so small I could fit it anywhere. I'm either going to strap it to the intake horn or fabricate a mount to put it in the same place I planned to put the Davco.



I also got the Aeromotive pump... it's remarkably heavy! I emailed the people at Aeromotive and asked about submerging the unit in water (it's going to be mounted on the transfer case skid plate, I think), and they said NO WAY. Splashing is okay but no submerging. So I'm thinking about building a water tight housing for the pump and regulator.



-Ryan

 

[realsquash]

Well I still don't get why you're going through all of this...



Be careful about boxing that fuel pump, you don't want to over heat it... .



Andy