Lift Pump Solution?

[CannonBall]

Has anyone tryed mounting an inline style pump on the frame near the tank? I am going to attempt this. The pump of choice is a Holley 512-105. It is a 15 psi pump at 68 gph. How many gph is the stock Carter?



This is a gerotor style self priming pump. It uses a 10 micron screen filter located behind the pump to help keep particles out that would jam the pump. Between this filter and the sock on the standpipe it should be well protected.



I am also thinking that the inline style pump should last quite some time. The fuel actually travels thru the pump moter itself and should keep things cooled and well lubed.



I talked to a Holley tech and he stated this pump was tested for 2500 continuous hours and disassembled and showed little signs of wear. This test was conducted while pumping gasoline. I questioned him on how this pump would stand up to diesel fuel and he could not answer. I guess I will find out. I would think that diesel would actuaaly be easier on this pump because of better lubricity.



I puchased some Deutsch style connectors to plug in at the engine wire harness at the factory pump location. Plan on running the wire harness down the frame and put like Deutsch seal connectors at the inline pump as well.



I am also planning on mounting the inline pump low on the frame to try to keep it below the fuel level. A shield will have to be made to protect it. Anyone have any thoughts on this?



Guy's, we have lift pump problems in a bad way. Mine is gone as well as two friends that went out at the same time. I have a fuel pressure gauge and caught my problem immediately. My two friends were not so lucky. One was left walking in the middle of the night in the middle of no where while the other guy's liftpump not only quit but wiped out the VP44 as well. It's time to do something.



Anyway, how many gph is the stock Carter liftpump? Will 68 gph to the trick?

 

[GRudy]

I'm not an engineer by any strech of the imagination but it seems to me that gasoline would stay pretty consistant in consistancy while diesel thickens as the temperatures drop. Could this be a reason the lift pumps wear out? Yea, diesel has better lubricating properties, but the thicker the fluid the more resistance to move it.

 

[Neal Cassady]

100 GPH

I think the factory pump is rated at approx. 100 GPH/15 psi.



Dave

 

[CannonBall]

George, I did consider the fact that diesel does change it's characteristics according to temperature. This may be the downfall to my idea. I could be just thinking out loud again.



Can anyone confirm that our stock pumps are 100 gph?

 

[redneckdr]

constriction

i think the constriction in the system is actually the fuel filter. i've read that the flow for the fuel filter is 45 GPH. i ran a low volume "pusher" pump feeding the carter for awhile. took it off, because pressures at WOT fell to essentially zero. this has been kicked around on several threads in the past. the best i can decipher, pump flow should be at least 70 GPH, preferrably 100 GPH and 15 psi to the VP 44. if you plan to push to the carter, should use a 70-100GPH 7-9 PSI pump.

 

[CannonBall]

Redneck, my plan was to eliminate the Carter and just use the inline pump on the frame close to the tank.

 

[EricBu12]

I did something similar to this but I didn't have a longbed to mount this on the frame, I mounted it beside the fuel tanks between the muffler and the tank so the pusher pump has only to pull the fuel 2' max. it is a 7lb 100 gph pump. the filter is a 30 micron with a WIF sensor and a heater and it also has a one-way bypas for starting and in-case the pusher fails, it can be drawn by the lift pump around the pump but still through the filter. it also has a vacumme sensor to tell when the filter is clogged. I also as in the pic, put a valve so you can change the filter without draining the fueltank. (makes for a good antitheft device too --the valve... )



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[chuck3]

Eric, that looks real pretty now, but wonder what kinda mess it will be in after a couple of winters? With all the road salt and slush it will get splashed on it I wonder if the wires might corrode up on the pump?

chuck.

 

[Steve St.Laurent]

Cannonball, I don't believe anyone has tried that particular pump. Quite a few gerotor style pumps have been tried though and I believe all have had failures of some sort. I believe the Mallory pump is a gerotor style (correct me if I'm wrong guys) and they've seen failures with those too. Here's what the description on the Holley in-line pump is from the Jegs website:

These Holley universal, in-line fuel pumps are intended for fuel injection systems. They are designed to work in-line, not inside the tank, so installation is a snap. They're great for testing and tuning or as a spare back-up. They should be mounted below the fuel level of the tank for a good gravity feed on the inlet side.

That makes it sound to me that it's not meant for continuous duty like most of the aftermarket electric fuel pumps. The stock Carter pump is rated at 100 GPH at 14-16 psi, the "helper" pusher pump that I'm running is 100 GPH at 7 psi. If you decide to try it make sure to update us on how it holds up.

 

[CannonBall]

Steve, I think the difference between some of the gerotor pumps that have been tryed in the past and this particular style is the fuel actually travels through the armature, brushes commutator etc. This should help tremendously when it comes to cooling and lubricating the electronic portion of the pump itself.



Did the gerotor pumps you spoke of that failed operate in the same manner or were they simular to the stock Carter where the electric motor is seperate from the pump portion of the motor.



I just got back from purchasing some diesel fuel. One can has straight #2 while the other is a 50/50 blend. I am going to do a makeshift flow test with these two fuels heated to about 60 degrees F. I will compare the results to what the pump is rated to flow.



The second test will be to set both jugs of fuel outside and let them get cold. We are going down to about 0 degrees F tonight and I will conduct another makeshift flow test.



Somehow I am stuck on trying a pump that will allow fuel to pass thru the electric portion of it. i have had great luck with Walbro pumps in the past and they use this method. I will post my results of the flow test later.

 

[csutton7]

the main problems with our lift pumps in the stock location is two fold---



1) they are to far from the tank

2) they are not gravity fed



all electric pumps like to be within a given

distance to the tank(4' or less) and gravity fed--this of course excludes in-tank pumps



now we have moved them closer to the tank which helps to remedy one of the problems, but you still have the gravity feed to deal with---we have added another pump to the system which helps keep pressure to the OEM pump, but you still haven't remedied the gravity supply, plus now you have two pumps to deal with----oh what to do--





use one pump and get it gravity fed is the answer---yes this isn't the easiest thing to do but mine has been for 9 months--and even though it's not long enough to state that this is the perfect system; it does cover all the requirememnts of the electric pumps wants, so I'm confident---the pump I'm using is an Aeromotive--it's a flow through design---it puts out alot of pressure and threrefore must be regulated with a separate return line---again this is most likely more than the average guy will want to do, but we shall see how long this pump holds up and then people can make their own calls on the pump and system they want---



again it's been about one year when some of us started using different pumps and plumbing configurations, so data should be coming forth in the next few months--chris

 

[CannonBall]

The first phase of my flow test is now complete. You talk about making a mess! Anyway, Using an empty gallon can I first pumped a gallon of straight #2 diesel that was heated to about 60 degrees F. It took 47 seconds.



I then pumped a gallon of 50/50 blend with my new pump. It also took 47 seconds. It appears as if it the blended fuel did not flow any faster. You would think it would have been a little faster considering it is thinner.



This pump is rated at 68gph. My calculations say it will pump 76. 59 gph. Someone pointed out earlier that the filter head can only handle 45 gph so I am not sure if having a 100 gph pump would even matter.



Here is where things got messy. After doing these make shift flow tests I attemted to dead head this pump by putting my finger over the end of the hose. Nothing doing. Fuel everwhere. This pump is also very quiet.



I now have about 2 gallons of a 66/33 blend setting outside. I will conduct another flow test later to compare how cold fuel will flow thru this style of pump.



Steve, you mentioned this type of pump was not made for continuous duty. As I stated earlier a tech from Holley contends this pump was ran continuously for 2500 hous while pumping gasoline. It was also disassembled and showed little wear. At least that is what the guy told me. Who knows?

 

[Steve St.Laurent]

I don't know if they are or not Cannonball, I was just mentioning that the description on the Jegs site says "They're great for testing and tuning or as a spare back-up. " Which is what made me think that they may not be rated for continuous duty.



-Steve

 

[ynot]

In June, I'll have two years on a Holley 12-802 mounted on the frame where the up-bend is to the Carter. 18psi idle; 9. 5 psi at 50psi boost. I've two staged transfer pumps for years, never a prob. Good luck... T

 

[ynot]

Correction. 12-815 Holley. The 802 was on the Chevy (works fine, just subtract 2. 5 psi from above numbers). Sorry 'bout that... T

 

[csutton7]

Tony--sorry I forgot about your two pump system---and I knew about it from way back when---just haven't heard much on it since we were smacking pumps and systems around about a year ago----maybe you should post how you wired it and plumbed it one more time to update everyone---2 years is awesome----chris

 

[ynot]

Hey there Chris. Long time, buddy! Good to here from some of the "old timers" (sounded bad, didn't it ;-) ). T pumps; no prob. Cut the steal line about 3" before the upwards turn towards the OEM Carter. Screw Holley to frame. Cut enough out of the line to use rubber gas line to connect to Holley. Tap the power wire to the Carter to feed Holley and ground the other. All done. 20 minutes. I did put a Holley regulator at the pressure side of the Holley ('cause I had one left over that comes free with the 802), but it isn't necc. Have fun!! ... T

 

[CannonBall]

Well, here are the results to the second phase of the flow test for the Holley 512-105 inline fuel pump. I had a blend of about 66/33 setting outside all day long. When I brought it in the temperature was 7 degrees F.



The pump took 52 seconds to flow one gallon of fuel. I did three flow tests in a row and the results were the same. This is five seconds longer than the tests I performed earlier in the day with the same fuel that was heated to about 60 degrees F. No surprise here. Under these conditions the pump will flow 69. 23 gallons of fuel an hour. It is rated at 68 gph with gasoline.



These flow tests are also makeshift so I really do not know how much merit applys. At any rate, whether it be the pump I am testing or the OEM Carter, they work harder , especially in the cold conditions when pumping diesel fuel. As stated earlier, gasoline is really not affected by cold conditions. Diesel fuel on the otherhand is.



It only makes sense to me though that if a fuel pump is going to struggle to move fuel it should be cooled and lubricated by the fuel it is trying to flow. It also makes sense and has been proven that these types of pumps would rather push than pull.



Electric transfer pumps are nothing new. Our M-series 2 1/2 ton trucks we had overseas were equipped with in tank electric transfer pumps feeding a Bosch inline fuel injection pump. It also got very cold as well. I never recall having problems or changing a transfer pump. These trucks were 60's vintage. This method does work and can be done.



I realize there are people having sucess operating with twin fuel pumps but I am not quite sure that is necessary. Afterall, this is a 15 psi system and in comparison to other fuel system, 15 psi is minimal. One pump, located in the right position, and of proper design should do the trick.



I hope to have this pump installed by the end of next week. I will also keep everyone up to date. Hopefully it will work.

 

[yogibear]

Thats a neat looking little pump Gordon, hope it works!! Get the Shop all cleaned up before I get there Get some heat in there, and the smell won't last long. Keep us posted!

Larry

 

[csutton7]

ynot--yea it's good to hear from you also and thanks for posting your plumbing/wiring configurations on your setup---your setup to date has outlasted any other setup tested, that I know of----



cannonball---great testing and it will be awesome to see what this pump will do---what hp are you running-- and let us know what pressures this baby puts out -----chris