Christmas came early and the machine shop was able to finish my engine. Being that it is an 880 block, it has no mechanical fuel pump provision, which is perfect because I want to go the electric fuel pump route.

So, if could get some advice on:

1) Fuel pump - only needing to fuel up to 500 hp. - Also prefer internal regulated so no need for return line.
2) Fuel pump placement
3) Fuel pressure regulator
4) Best way to wire it up. Open to larger separate relay block type of system to cleanly wire electric fans in as well.


Thanks in advance!

 

I'd probably fabricate my own using an 82 fuel sender so I could pull it out of the top without dropping the tank, but here is an easy, but really expensive, way to satisfy up to 550 HP: https://www.holley.com/products/fuel...s/parts/12-312

Also it is internally regulated----- at 58 psi so be aware of that value.... if your EFI is a different pressure.

If I was going to get one of these, the I'd get the 82 model, and modify that 75 tank, just so I could pull it out the top.
https://www.holley.com/products/fuel...s/parts/12-313

 

Sorry, should have clarified. The engine will have a carburetor. Not sure this will work due to its internally regulated at 58psi of fuel pressure.

 

ahhh...... that's a horse of a different color. The electric fuel pump part is fairly easy. You can get an 82 sending unit and mount a lower pressure efi pump on there that would be "regulatable"down to carburetor pressure. Might have to modify for tank depth and whatnot...but nothing horrible. You can even get a Holley Hydramat to ensure you don't lose suction. I actually modified mine to install a cannister pump and it comes out the top still.

Your "internally regulated" idea sounds a bit tougher.

When I modified an 82 sending unit for my 68 EFI I considered mounting the regulator in the back, near the fuel tank, and then using the small parallel "vent line" that runs back to the fuel pump, as a vaccuum signal for the regulator.... but since I wasn't terribly concerned with doing the regulating in the back.... I just went with running a return line. That might be something "do-able" .....but just a guess from something I was considering.

 

Just to clarify. What year is this car? 82 sender is a good solution but only fits tanks back to 78. Your name has 1975 in it. But I have assumed in the past that was the year of the car only to be corrected.
If the car is a 75. I have solutions but the tank will need to be dropped out.

 

I used an Aeromotive Electric fuel pump with an Aeromotive PWM Electric fuel pump controller that kept it slow and quiet out back of the car. I used an external pressure regulator that sent the return fuel to the return line inlet on the original 1968 Fuel tank that I have in my 1968 C3 convertible. This was easy to do and the parts were rubber insulated and the system was quiet.

Currently I am using a Holley Stealth Sniper on my 427 and it looks just like a big double pumper Holley carburetor but is a Electronic Fuel Injection system. I installed the Holley OEM Fuel Tank Module for the 1968 style fuel tanks and this did not require the removal of the tank. As a matter of fact it took less than 1/2 hour to install the pump, pressure regulator and new level sender in the tank and was easy to wire from there since I had power wires going back there already. You simply remove the fuel outlet and Tank level sending unit out in one piece and simply replace it with the new Holley piece. Holley even included their new Hydra Mat in the kit to make it a sweeter deal. IF you even want to go with a Holley EFI system this is the easiest way to get your fuel system ready for a steady 58 psi output.

In your case buying a electric fuel pump that is able to sustain the HP level you need should not be hard and an inexpensive regulator is really all you need. The Aeromotive PWM Controller is not cheap but it does make a much nicer system as the equipment is able to run as slow as it needs to making very little noise. The Aeromotive parts were more expensive than the Holley parts for a carburetor but were very well made and extremely reliable. I tried a Holley setup and had issues and that is what made me switch to the Aeromotive parts. Just be sure to isolate the fuel pump from the frame or you will hear it all the time, this is a valuable lesson learned. If there was a way to use a fuel pump designed for the low pressure you need in an inside the tank frame it would be the very best for noise and simplicity. Keeping the pressure regulator near the tank helps reduce fuel lines running all over.

Best regards,
Chris

 

If he's willing to fabricate, then the 82 sending unit is a good starting point. I actually modified one to hold a cannister pump on my 68. Lemme see if I can find the thread. It would probably be even easier on a 75 since he could take measurements and then drop the tank to modify the big ol' hole in that thing.....not that he needs to. Lemme find my thread..... I'll be back.

Here it is below. Looking back, it would have been easier to relocate the electrical connector to make it fit inside the 68 pre-existing hole. I'm quite happy with it anyway since I can pull the thing out of the top and no need to drop the tank:

https://www.corvetteforum.com/forums...surements.html

 

I have a ‘79 so a ‘82 sending unit can be used.

 

That's great. And yes the 82 sender will work perfectly.
Perhaps you could update your profile to include what car you have. And, just a thought, so we don't have to bring up your profile every time you ask a question, might be good to put in pertinent information. Like year of car. So answers on how to do it on a 68 or a 75 that mean nothing to you could be avoided.
Just a thought.

 

I dont jknow if you want to go EFI or not. Assuming you are not, I ran a separate 10 gauge power line from my battery up the center console to the passenger side dash. Lots of room behind it. There I put in a relay that is keyed to the ignition. I ran , that one is for the electric fans. No need putting all the amps through a single relay. The fans went out through the top of the fire wall in the center beside the wiper motor, there is a little bench there that provided room for a small hole and grommet.
THe trigger wire for the pump was run from there along the passenger sill plate and back to the upper passenger rear fire wall. I have a relay in that area and the power line comes straight from the battery along the outer edge of the trunk area to that relay. You can put in your fuses either in the battery compartment or where ever it is easy to get at.
MY pump is mounted low on the rear frame where the fuel line comes out of the bottom of the tank on the early cars and originally joined to the steel fuel line.If your line comes out of the top of the tank you can find a suitable place. the fuel tank sits above the originally fuel pump so its fed with head pressure from the tank, not siphon fed on the 68. As long as you dont run it dry it could work for you
I have side exhaust so there is plenty of room back there to run the fuel lines. I have a pre-pump fuel filter then the pump all using an-6 line. You can get the hardline adapaters so its easy to go from an-6 to 3/8 hard line. Anty rubber line I do have to use is 100 psi EFI fuel line and clamps. I use the Holley blue pump an its loud with the motor off but once the car is running I dont hear it above the side pipes and stereo. The blue pump is only 9 psi so
I dont run a return line from the regulator. Witht he big block its using as much fuel as pump supplies so I dont worry about back pressure at all.

from the original hard line again I run an-6 up the fender to 100 micron filter then onto a fuel cooler in front of the radiator. It comes back into the engine compartment and hits the Holley regulator and gets knocked down to 6.5 psi and converts back to the hardline for the tripower.

 

Thanks for for everyone’s info. I was also considering a Holley Blue pump as my carb only needs 6.5 psi. The noise issue is concerning thou. I was very aware of using the ‘82 sending unit with Corresponding fuel pump, but wanted to stay away from this due to serviceability issues. I want my car so easy to work on a MOPAR guy could do it… (Ha! Kidding, my first car was a ‘73 Barracuda) Which is why I didn’t mention the year of the car. Curious to see what has been done using an external pump.

 

A Holley “ blue” puts out between 7-14 psi, and will require a regulator. It used to come with their standard, non-return regulator, but I cannot testify as to whether or not it’s included. I just went through all of this with my 80, and ended up using the 82 internal pump/sender unit, and purchased a return regulator to choke down the 25-30 psi that pump will put out. I’m running a carburetor as well. The fact that an electric pump “ pushes” instead of pulls means that you’ll have to mount it at the rear of the tank, and even at that, still has to suck fuel up and out of the tank. Additionally A Holley blue will be noisy, and I wouldn’t trust it on a daily driver, fuel gets hot, the pump starts to ****-n-moan, and next thing you know, you’re sitting in the side of the road. It’s just not what it used to be.

 

Some quick thoughts for you which you may or may not want to follow up on. I did this so long ago the details are starting to escape me, but here goes:

• As MLM says, the pump needs to be at the back of the car, under the tank somehow
• If I was going to do this again, I might decide to go with an in-tank solution but typically that is only done with EFI
• The Holley pumps are noisy, I went with a bastardized Edlebrock to get the plumbing to match my cars lines and still have adequate HP capacity
• I did use the return line as a way to help regulate the pump. The Edlebrock had a built in "regulator" but I think all it was was a spring and I didn't trust it very much
• You need an inline fuel filter that is easy to get at and replace or clean when necessary
• Didn't have any feed problems with the pump mounted a bit under the tank, even autocrossing. Will see if I can come up with a picture below
• You need a way to shut off the pump if the motor stops, I used oil pressure, there are wiring diagrams / relays, I forget exactly what I used.
• I would suggest PWM is a better way to regulate pressure but you need a pressure sensor,
• I used a Quickflow manifold to a Holley double pumper which had a built in tap for a pressure sensor

If you want any elaboration, I suppose I can get to it but I don't know what you know or don't know, these are just some things that I thought were important ten years ago.

 

Just to add to the post above this,

You will need a bypass regulator and a return line if you are running an electric pump with a carb. What happens is when you switch off the engine the fuel line is still pressurized and can stay that way for hours . That pressure is held by the needle and seat of the float and can eventually seep past it and down into the manifold. This will flood the engine in the short term and can dilute the oil with fuel in the long run. With the bypass regulator and return line the pressure drops to zero right away.

You defiantly want the pump to stop if the engine does, some cars also shut the pump off in a rollover condition....

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