Fuel Pump for Carb?

LT1B-Body

Greasemonkey
Feb 25, 2021
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Maricopa Arizona
Hello,
This is my first time trying to piece together a carbureted fuel system. I'll have a Holley carb on a stock 305 and I'm planning on using the factory fuel line for a deadhead electric fuel pump setup. I'd love to use a mech pump, but the roller cam in the engine has no provision for one, so I'm just going electric. Holley has a low psi carb pump and regulator combo, but is $200. I'd like to go with something a little more basic and cheaper. Any suggestions? What's worked well for you if you have a deadhead setup?
 

ck80

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Hello,
This is my first time trying to piece together a carbureted fuel system. I'll have a Holley carb on a stock 305 and I'm planning on using the factory fuel line for a deadhead electric fuel pump setup. I'd love to use a mech pump, but the roller cam in the engine has no provision for one, so I'm just going electric. Holley has a low psi carb pump and regulator combo, but is $200. I'd like to go with something a little more basic and cheaper. Any suggestions? What's worked well for you if you have a deadhead setup?
I have to ask... why, other than saving a few dollars, are you choosing to run a deadhead regulator instead of a bypass regulator if I understand your plan properly?

Only benefit I can think of to a deadhead regulator on an electric pump is cost for a n/a carbuerated engine.

Negatives include:

Much worse odds of capor lock problems, since youll have heightened temps of fuel getting heated up in the pump.

would need a higher pressure to close the valve that can surge the output pressures, overpressurize and/or overfill fuel bowls.

Being an electric pump and id expect already pushing higher pressures than the mechanical diaphragm pumps youre going to have back pressure stressing the pump as flow chokes off, making more noise, more heat (see yet even more vapor lock potential) and, even shorter pump life...

I guess I'm just trying to see where and why the benefits outweighs the downfalls.

IMO a bypass style setup would make more sense with a carb setup, especially in a street driven car and especially even more so if it's driven on any kind of warm weather or over hot asphalt
 
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LT1B-Body

Greasemonkey
Feb 25, 2021
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I have nothing against a return system, if it was EFI I wouldn't even question it. The car just has only one fuel line and the tank and sender are for a carbed setup.
Would I have to run a return line back to the tank for a bypass regulator?
 

69hurstolds

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Jan 2, 2006
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I ran a dead-head Holley electric to a regulator to the Holley carb on top of the 502 (no fuel pump boss) in my bubba truck. Had 6.5 psi on the gage all day long. Mounted the pump on the frame with the inlet/outlet about the bottom of the gas tank level and never had an issue.
 
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Cauterize

Floater of Valves
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Feb 9, 2019
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I ran a dead-head Holley electric to a regulator to the Holley carb on top of the 502 (no fuel pump boss) in my bubba truck. Had 6.5 psi on the gage all day long. Mounted the pump on the frame with the inlet/outlet about the bottom of the gas tank level and never had an issue.
I ran into a similar situation when I put the TBI truck engine into my old 84 Regal. The block wasn't drilled for the fuel pump push rod.I ended up running this Carter unit. I spliced it to the factory rubber fuel lines by the sending unit. I fully expected to have to put in a regulator. It ended up being 6 PSI and was pretty much perfect.
Screenshot_20230319-121538_Chrome.jpg
Screenshot_20230319-121558_Chrome.jpg
 
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LT1B-Body

Greasemonkey
Feb 25, 2021
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Just had a thought, could I use the vent line as a return? The vent runs from the tank all the way to the front of the car. It's on the the opposite side of the supply line, but that's hardly an issue. I'd just use a vented cap and not worry about the EPA emissions crap.
Thoughts?
 
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Ernest

G-Body Guru
Apr 28, 2016
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CopperNick

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Feb 20, 2018
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Using the vent line as the return is problematic. What you might encounter is the returning fuel showing up at the tank evap canister instead and pissing all over the place. You should be able to drop the tank and sub in a three port sending unit that has the feed, return, and vent. One from a mid 80's G-body gas tank ought to be just right



881-3478-33-4.jpg

This is a Spectro Brand sending unit for an 85 Monte. Pretty much a case of swap and drop; it, or any like it from wherever ought to solve your third line/return issue and let you run the bypass regulator quite easily.




Nick
 

Clone TIE Pilot

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I don't know about 78, but 80's G bodies used a return style fuel system for their carburetors to avoid vapor lock issues.

Its best not to delete the Evap system as it keeps your fuel system from gunking up like with open venting. Also prevents that gassy smell when parked.
 

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