Fuel pump requirements

Mike Pearson · 11-26-2019, 02:00 PM

My car has one of the knock off holley pumps from summit. It runs 10.0@ 130 with a q jet carb. #8 line from the cell to the carb. I have a magna fuel regulator. Low 1.30
60 ft. No issues with fuel delivery. Kind of old school set up but is working OK

Dissident · 11-26-2019, 11:44 PM

From something I wrote a while ago.....
Even lower horsepower racecars can benefit from a detailed investigation of how to build an effective fuel system for a drag racing application. An assumption of “….if the car runs good and it 60 foots hard, then the system is OK…” is far from the truth. Many folks are comfortable with not knowing the facts. Don’t be one of them. Being informed will improve your racing results....

FYI - A Holley carburetor with center hung floats has an operational float bowl volume of 0.066gallons (251.34cc) and a QJet has an operational float bowl volume of 0.022 gallons (81.94cc). The Holley when mounted fore and aft has the primary float opening the n&s under accel while the secondary is trying to close its side off. The QJ is trying to close the flow off.....When under accel g, the system line pressure (before the regulator) must oppose the g.

There is lots to the details of making a system the best for the application instead of just writing checks.

Regards to all that like this kind of stuff,

HB2

Dissident

11-26-2019, 02:00 PM	#1
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,456 Likes: 618 Liked 1,945 Times in 586 Posts	Re: Fuel pump requirements My car has one of the knock off holley pumps from summit. It runs 10.0@ 130 with a q jet carb. #8 line from the cell to the carb. I have a magna fuel regulator. Low 1.30 60 ft. No issues with fuel delivery. Kind of old school set up but is working OK __________________ Mike Pearson 2485 SS

11-26-2019, 11:44 PM	#2
Dissident Member Join Date: Jan 2016 Location: Colorado hills Posts: 123 Likes: 11 Liked 73 Times in 36 Posts	Re: Fuel pump requirements From something I wrote a while ago..... Even lower horsepower racecars can benefit from a detailed investigation of how to build an effective fuel system for a drag racing application. An assumption of “….if the car runs good and it 60 foots hard, then the system is OK…” is far from the truth. Many folks are comfortable with not knowing the facts. Don’t be one of them. Being informed will improve your racing results.... FYI - A Holley carburetor with center hung floats has an operational float bowl volume of 0.066gallons (251.34cc) and a QJet has an operational float bowl volume of 0.022 gallons (81.94cc). The Holley when mounted fore and aft has the primary float opening the n&s under accel while the secondary is trying to close its side off. The QJ is trying to close the flow off.....When under accel g, the system line pressure (before the regulator) must oppose the g. There is lots to the details of making a system the best for the application instead of just writing checks. Regards to all that like this kind of stuff, HB2 Dissident

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