Failing Fuel Pumps
 

I had to replace the fuel pump again....for the 3rd time on my Thunderbolt stocker. Lost a heads up first round because of it! After the second pump failed I contacted the manufacturer to discuss the failures.......talked about filters, mounting, hose size, and voltage? They said it was the voltage, my 16v system was spinning the pump to fast. Ok I installed a voltage step down unit before the pump giving it 12.7volts.
Failure #3 I called the manufacture again and discussed why I have had pumps fail.....discussed filters, mounting, hose sizes, voltage etc. They agreed that everything is how its suppose to be, but would not offer servicing or replacing the pumps. I tore into the pump and it has basically ate it's *****? Rotor, vines, and housing are tore up. I buy VP C-25 straight from the track so no chance of contamination. What am I doing wrong? Is the fuel to blame? Is the pump junk? Help?

Re: Failing Fuel Pumps
 

Probably the pump. I see you did not offer up which pump it is. You might think about one of the Weldon pumps. Supposedly they have a lifetime warrantee. I still have Holley Blue pumps on my car and they have served me well. Not sure what to replace them with when its time. I am sure the new ones aren't as good as the older ones like I have.

Re: Failing Fuel Pumps
 

Tom, what brand of pump are you using? Like Mike, I have had very good luck with the old style Holley GPH110 "blue" pumps. I have had the same 2 Holley blue pumps on my bracket car for over 25 years, and a single blue on my Mustang for 13 years. In all this time, the only issue I ever had was to replace a leaking bottom cover plate gasket, and I replaced the Holley regulator diaphrams twice, when they dried out from sitting. I understand that keeping a small, single float bowl like a Q Jet full is a big job, I think that a lot of guys go overkill on fuel systems for carbs with lots of bowl capacity, like a Holley carb. Back when Bob Glidden was racing Thunderbirds in Pro Stock, I looked inside the trunk and all I saw was a pair of Holley blue pumps.

Re: Failing Fuel Pumps
 

Tom,

One of the best fuel pumps in the market is made by Product Engineering.

http://www.product-engr.com/fuel_pumps.html

They have a 2-year warranty and if the pump fails, they will replace it no questions asked.

Re: Failing Fuel Pumps
 

How is the pump located in regards to the fuel cell? If the pump is cavitating that will damage it. The fluid head above the pump will reduce-eliminate cavitation. If the pump is getting mechanically damaged a restriction from the fuel cell to the inlet of the pump needs to be checked on. Is there foam still in the cell, how many and type of fittings (45,90) from the cell outlet to the pump inlet? If it is a return system, is it aerating the fuel where it is dumping back into the cell? The larger the inlet, hose and fittings are, that will reduce the chance of cavitation too. If 3 pumps have failed, have they all failed mechanically?

Most fluid pumps if damaged, it is due to a low pressure condition at the inlet of the pump which makes the fluid boil, and cavitate. When the pump has no fluid to cool it or provide a constant load or resistance that will damage it too.

Sean

Re: Failing Fuel Pumps
 

Yes Tom. How is your pump plumbed. Do you have a diagram, or a picture of how your lines are routed. I cooked my Magnafuel pump a couple of years ago. I was running a Summit 5 gallon fuel cell. And the provisions for the vent tube, and return line were located at the rear of the cell. When the car was under acceleration it would occlude the vent, and the pump would eventually cavitate. After about 65 runs it just burned up. And ruined the pump vanes. I had Magnafuel rebuild it. They said it was cavitating. But i couldnt figure out why. Had to just figure out where the fuel was moving to during a run. You might have to do a little detective work.

Steve

Re: Failing Fuel Pumps
 

What kind of pump is it? I ran BG pumps for a while. The first 280 I had worked well and ran a long time. It finally stopped working after 5 years. I bought a new one, and lost it after 2 months. The rotor ate the bottom of the plate. Got another one, same thing. Looked into it more, the plate was made of soft steel, compared to the original. Barry Grant got cheap and used inferior metal later on. Maybe the same thing is happening on your end?

Re: Failing Fuel Pumps
 

It appears that Tom already addressed the installation, routing, filtering and power supply of the pump with the vendor...3 times.

It would help to know the brand of the pump.

Re: Failing Fuel Pumps
 

Aeromotive A2000 pump is mounted 3" lower than 5 gal cell that we keep full. -10 line, -10 filter before and after pump. -8 return line to the top of the cell and a -8 line on the vent that has a 1/2" K&N vent filter on it.

Re: Failing Fuel Pumps
 

I am surprised at that. Most give Aeromotive good reviews. Lots of those being used with 16 V systems.

Re: Failing Fuel Pumps
 

Tom,

You have more than sufficient line size for your application. Also, which regulator are you using?

There have been issues with the Aeromotive A2000 fuel pump rotors wearing out and breaking too. Aeromotive also releases a new pump model, A300 as a substitute to the A2000.
Also, a friend of mine was told by an Aeromotive tech to not run the pump for a long time either.

My preference for pump has always been the Product Engineering or Magnafuel pumps. I believe Magnafuel is the same pump as the Product Engineering. They are robust and the customer support is great. If you run either pump, use their recommended regulator too.

Re: Failing Fuel Pumps
 

This is the Fairlane fuel system.......the fuel pump has been lowered since this photo and after the first pump failure. I have Aeromotive 4 port Pro-Stock regulator, dual 4 barrels with side hung bowls, 6.5psi. My major concern is I built my hemi car fuel system the same.....using the same pump.

Re: Failing Fuel Pumps
 

Hemi car fuel system photo.

Re: Failing Fuel Pumps
 

Tom,

That's a very nice neat installation. I am envious. The only issue I can see is the loop in the vent line. I would get rid of the loop. If you get any liquid in that loop it will act as a trap and wont let the system vent. Looks lie the vent in the hemi car is straight.

Re: Failing Fuel Pumps
 

Ok thanks, good advise, I raised the filter as high as I can and took out loop on the hemi car and will do the same with the Tbolt.

Re: Failing Fuel Pumps
 

On my car I ran the vent down through the trunk floor using a bulkhead type fitting. The filter might also be slowing the vent process especially if the filter media gets wet from fuel. You might thing about ditching the filter as well. I think by the rule the vent is supposed to be plumbed to the exterior of the vehicle. I would check the rulebook on that too. Hope it helps to fix your problem.

Re: Failing Fuel Pumps
 

One thing I was told is to put pump behind outlet so G force pushes fuel in pump,not sure how much difference it would make,but I know pumps don't pull fuel well they are made to push it.
Mike Taylor 3601

Re: Failing Fuel Pumps
 

BTW if anyone needs parts for BG 400 had a friend got some parts I believe was www.carbs.com,the piece that the vanes rub was ate up they had replacement in steel? had upgraded parts anyway.
Can't remember Product engineering's owners name off top of my head,but he designed BG 400,Grant patented it on him,then designed the Magnafuel style with filter built in.
Mike Taylor 3601

Re: Failing Fuel Pumps
 

Tom,
I have seen your car run and I know you do not have a fuel delivery problem.
If you fuel cell was not venting and the fuel filter causing an issue, you would have seen it affect the performance of the car, especially on a high horsepower car like yours.
Your fuel pump is installed like many other racing pumps.

Re: Failing Fuel Pumps
 

Is that a regulator with return before the pump on the suction side?

Tim

Re: Failing Fuel Pumps
 

I just zoomed in on your picture and it appears you have the outlet facing towards the rear, which means your supply side is coming out of the cell and going around the battery to the front of the pump, that would cause cavitation if that's the case.

Re: Failing Fuel Pumps
 

I thought I seen the same thing but wasn't sure.

Re: Failing Fuel Pumps
 

Great catch Tom!
On the Ford installation, the fuel pump outlet is backwards and you can see the casting inscription "OUT" towards the rear of the car.
I have marked the area with the inscription.

On the Hemi car, the pump is installed correctly.

Also, in both installations, as it was said before, the venting has to be routed to the exterior of the car.

Re: Failing Fuel Pumps
 

Aeromotive guy said the little bit extra hose will not cause cavitation! Only way to have cavitation is to suck air....the hose is full.

Re: Failing Fuel Pumps
 

Tom, did you look at the picture in my last post?
I marked the area showing what appears the fuel pump outlet is towards the rear of the car.

Re: Failing Fuel Pumps
 

Had the same problem with the Aeromotive. Was told by Aeromotive that you need #12 from the cell to the pump because it pumps so fast with the 16V. I see that the Product Engineering pump says to use #12 line also.

Tom, I see you dropped the voltage with yours and still have problems, did they recommend that you do that?

Re: Failing Fuel Pumps
 

Cavitation can be caused by a low pressure area at the inlet of a pump and fluid will boil. With the pump mounted where g-forces are acting on the pumps ability to have fluid being pushed into it on acceleration it may be the problem for the mechanical failures. We run into similar problems like this on open hydronic systems.

Did Aeromotive give any reasoning for the mechanical failures?

Re: Failing Fuel Pumps
 

I will turn it around. Thanks for your help guy's.

Re: Failing Fuel Pumps
 

[QUOTE=Mike Taylor 3601;
Can't remember Product engineering's owners name off top of my head,but he designed BG 400,Grant patented it on him,then designed the Magnafuel style with filter built in.
Mike Taylor 3601[/QUOTE]


I believe that the missing name is John Rademacher. He advised me on setting up the fuel system on my LT1 Super Stocker almost fifteen years ago. Worked flawlessly.

c

Re: Failing Fuel Pumps
 

Hi,

With a filter installed in the supply line to the pump you have the potential to have a restriction.......

With a restriction you could have a negative pressure in the line causing the fuel to flash into a gas (vapor lock) and have pump cavitation which will destroy the pump....

I would recommend removing the filter between the tank and the pump and if you are worried about trash in the pump use a filter funnel to add fuel...

Hope this helps,
Bob

Re: Failing Fuel Pumps
 

John gave me some advice to put a return on the regulator with a jet to take out the cavitation,I also run a T-Bolt 5 years on the same pump a BG 400 go though the traps at 8000

Re: Failing Fuel Pumps
 

Not remotely true.

Sure the extra hose may not be a problem,but there are plenty of other ways that fuel can/will cavitate/aerate in the lines w/o "sucking air" as he states.

Also not too sure I would take advice from someone that does'nt know better than to say something like that.

This ^^^^.

Gasoline has a very low boiling point @ atmospheric pressures & temps,that's why it evaporates as rapidly as it does.

See,it's like coolant in a cooling system,raise said system pressure,you've just raised said fluids boiling point.

Lower the system's pressure below ambient pressure,you've just lowered said fluids boiling point.

Any restriction on the inlet side of the pump will inturn cause negative pressure (ie: vacuum) thus lowering the fuels boiling point,and yeah it can & will boil the fuel in the lines and that absolutely can & will lead to aeration/cavitation issues,that's just basic fluid dynamics @ work.

Fighting G forces,use of hard 90° fittings (or sharper),using too fine of an inlet side filter (<100 microns),using a filter with insufficient surface area,using improper hose size,inadequate system venting,all will be "seen" as a restriction to the inlet side of the pump.

All can lead to cavitation/aeration issues.

And cavitation/aeration left uncorrected absolutely will cause pumps to fail.

Funny thing is even Aeromotive says so in their tech bulletin #TB-101 on their website...

So it would seem the Aeromotive tech guy needs to read his own co.s tech bulletins and absorb said material more fully.

I prefer/use the Product Engineering pumps,and follow his (John Rademacher) system recommendations to the T.
(someone already posted the diagram in an earlier post,and do note that he advises no 90° fittings on the inlet side whatsoever)

FWIW ~ HTH

Bret P.