Fuel Pump for 502
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Joined: Aug 2008
Posts: 9
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Fuel Pump for 502
Will a Holley Red (7 psi) electric fuel pump flow enough to FEED a stock GM crate 502? The holley carb calls for between 5-7 psi.
I installed a Holley black (14psi) with a bypass regulator, but the stock return line is too small (5/16" or 1/4"?) and only allows me to drop the pressure down to 10.5 psi. I really don't want to drop the gas tank to install a larger return line.
I replaced the black with a red and I can now adjust the regulator to get a solid 5.5-6 psi without deadheading, but I am wondering if the lower flow rate of the Red will feed enough gas to the carb (holley 4150) at WOT.
I am planning on doing inital engine startup and break-in tomorrow morning and any help with this would be greatly appreciated.
I installed a Holley black (14psi) with a bypass regulator, but the stock return line is too small (5/16" or 1/4"?) and only allows me to drop the pressure down to 10.5 psi. I really don't want to drop the gas tank to install a larger return line.
I replaced the black with a red and I can now adjust the regulator to get a solid 5.5-6 psi without deadheading, but I am wondering if the lower flow rate of the Red will feed enough gas to the carb (holley 4150) at WOT.
I am planning on doing inital engine startup and break-in tomorrow morning and any help with this would be greatly appreciated.
Melting Slicks
Joined: Oct 2008
Posts: 2,154
Likes: 69
From: Regina Sk Canada
well i had a Holley 110 GPH mechanical pump on my 427, and it made 550HP and 513 TQ . It was preset to 7 PSI, and would drop to 5-PSI at the top of the quarter mile. I had a steel 1/2" fuel line from the tank to the pump, then 3/8 to the carb. It seemed to work. Go to Barry Grant's site, he has a formula there for calculating fuel delivery . If this is a mild 502, you wont need a lot of fuel pump to keep it fed. You need the volume over the Pressure, make sure your supply line is at least 3/8-1/2"
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
The red pump supplies enough gph for it during normal driving & accelerating.
You may run into trouble if you race the car and have good traction.
In that situation, the g forces generated during a hard launch could cause problems with fuel supply.
Since you already have it installed, I would try it and see how it works.
If it cant keep up, then switch back to the black pump with a standard deadhead regulator.
You may run into trouble if you race the car and have good traction.
In that situation, the g forces generated during a hard launch could cause problems with fuel supply.
Since you already have it installed, I would try it and see how it works.
If it cant keep up, then switch back to the black pump with a standard deadhead regulator.
