switching to an electric fuel pump

[allcarfan]

Well, i decided to switch to an electric fuel pump. I decided on a holley blue pump. It flows 110gph and should be fine for my application. I know I need an adjustable regulator, and a return line to my gas tank from the regulator. Anything else I need for this conversion?

The holley blue pump and regulator can be had for just under $100.....I thought that was pretty good. The pump can also be bought brand new on ebay for $50 and an adjustable regulator can be bought at any parts store for about $25.

Shane

 

[BlueMonster65]

electric pump

with the holley blue a return line is not required. it has an internal check valve that allows it to bypass internally when fuel is not required. also you will probably have to redo most if not all your fuel lines. that electric pump must be gravity fed, close to the gas tank prefereably lower than the lowest point of the tank. i put mine on the inner rear quarter panel. and put a fram HPG-1 filter between it and the gas tank. i located the filter directly infront of the gas tank behind the rear diff. it allows for just enough clearance. the best set up using the blue pump would have it feeding the mechanical pump at the engine then regulating that before the carb.

 

[allcarfan]

Well, I want to get rid of the mechanical pump alltogether. Knowing that I dont need a return line with the blue pump is a gooood piece of information. Thanks Blue. I have new fuel lines that need to be bent and installed. And I have about 10ft of braided line the same size.

 

[porkchop]

I just installed a holley blue on my 71 Mach1. take BlueMonster65's advice and keep the pump mounted low. I did not have it mounted low enough the first time (about 1/4 the way up from the bottom of the tank) and it burned up the pumps motor. after i put on the new pump with it mounted at the bottom of the tank it works great.

 

[thehueypilot]

You might want to invest in some earplugs if you plan on driving it often. This "racing" pump is loud!

 

[allcarfan]

i dunno if i will hear it over my exhaust and noisy gear drive

i dunno if the blue pump will be enough. it flows 110gph@14psi. Does that mean it flows half that@7psi?

 

[Red Barchetta]

i dunno if i will hear it over my exhaust and noisy gear drive

i dunno if the blue pump will be enough. it flows 110gph@14psi. Does that mean it flows half that@7psi?

And with that, I post this link yet again.

Century Performance - Fuelish Tendencies

 

[allcarfan]

and with that I must say again....

I dont think that site is very accurate....speaking from personal experience.

 

[washMO66]

I run the holley blue and although it is loud when I turn the key prior to starting, after that it can't be heard over the motor, exhaust etc.

Mount your regulator as close to the carb for best results and the pump close to the tank as it is a pusher.

TB

 

[BlueMonster65]

more info

http://www.holley.com/HiOctn/TechServ/TechInfo/FMFPTech.html

the pump should not be loud. if it is it is most likey cavitating or the check valve is stuck. i had that happen on mine and the whole car shook from it it was so loud. once i repaired it i had no problems. i also have a blue pump on which the baseplate cracked. holley stopped making the replacement but i think quick fuel makes one now. yes the pump output varies with pressure go to the link below tosee a graph directly from holley that shows the freeflow volume to pressure relationship for the blue pump.

or click on attachment

 

[allcarfan]

Cool info blue.

Is that graph backwards though? It says the pump flows less at 14psi than it does at 3psi...or am I reading it wrong?

 

[BlueMonster65]

no that is correct it flows less volume at higher pressure. if you have higher pressure the fuel will flow faster but just as with a garden hose with a nozzel the volume will be less. think of it this way. to increase pressure you are essentially putting a restriction on the line. now the pump is working harder to try to maintain the same volume thru that restriction. that is why it starts to trail off as the pressure increases. some pumps work differently but the design of the rotory vane pump causes it to exhibit these properties.

 

[Red Barchetta]

and with that I must say again....

I dont think that site is very accurate....speaking from personal experience.

Do tell. What specifically is inaccurate?

 

[allcarfan]

Red,

8 years of drag racing (since i was 16), the previous owner of a twin turbo mustang with a complete aeromotive fuel system (according to the numbers on that site I should have had WAY more fuel than what I had) - but I still made 624.7 RWHP and the car never starved for fuel.

The previous owner of a completely hopped up trans am that made a little over 400hp to the wheels on a stock fuel line.

All of these vehicles I built myself...and raced....myself....and were daily drivers.

Actually SEEING cars at the track (1000s over the years) and at the dyno with a 3/8" line making over 500hp and the air/fuel mixture near perfect....according to that site, that line is only good to 375 hp.

Being a quality assurance specialist (mechanically certified) by the US govt and working with multi-million dollar vehicles every single day....yes, that means checking their fuel systems and what not.

I knew i was going to be at the limits with a holley blue pump and I just wanted to make sure I had enough. Every person that I have SPOKEN with...not on the net....we are talking drag racers and car freaks that have had more, built more and raced more that I even care to imagine...have all said that the line I have was just fine...again...according to that site...I should have replaced the line 125 hp ago.

I would say that I have a good bit of personal experience. graphs, math, formulas are all well and good...but actually seeing it in action is where you gain experience.

 

[BlueMonster65]

i too thought that that site was a little too conservative. the usual estimate for a 3/8 or -6an line is 450hp. but as allcarfan mentions in the real world math usual fails to accurately predict or explain what is actually happening and that is because in the real world there are too many variables. its ironic because i am an engineer and i hate math. also every car is different and presents a unique situation. what works on one may not work on another.

 

[Red Barchetta]

allcarfan,

I was just asking an honest question. You said you didn't think the site was very accurate, yet you did not elaborate as to why. Then, you ask if the chart that BlueMonster65 posted was backwards because volume dropped as pressure increased. Not trying to start anything, but I would have thought that someone with the qualifications that you listed would have known this.

 

[mdjay]

I haven't had great luck with Elec. Pumps. I also live in the desert and they are exposed to a lot more heat. I prefer the depedability of a good mechanical.