Fuel pump requirements - Page 2

Makinchips · 11-26-2019, 07:15 AM

Single Holley carb.

FED 387 · 11-26-2019, 11:05 AM

Take a moment and think about something! There is probably enough fuel in the float bowls on a Holley carb to do a burn out and make a full 1/4 mile pass before you run out of fuel at the 1/4 mile mark !!! How much fuel do you think is going to pass thru 4 little jets??? All you are trying to do is overcome the acceleration of the vehicle and keep an adequate supply of fuel going thru the carb to the engine--- Unless you have 600 inches or something like that and you putz around at the starting line a decent pump and large enough fuel lines should be able to supply adequately the needs for most applications. My .02 cents flame away if you want to .... FED 387

Makinchips · 11-26-2019, 12:20 PM

About 20gph at 520hp if i didn't screw the math up.
1/2 lb of fuel per 1hp i think?
That's all fine accept the cust tells me it stops pulling around 6000 in high gear

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

Eman · 11-27-2019, 10:07 AM

Quote:

Originally Posted by FED 387

Take a moment and think about something! There is probably enough fuel in the float bowls on a Holley carb to do a burn out and make a full 1/4 mile pass before you run out of fuel at the 1/4 mile mark !!! How much fuel do you think is going to pass thru 4 little jets??? All you are trying to do is overcome the acceleration of the vehicle and keep an adequate supply of fuel going thru the carb to the engine--- Unless you have 600 inches or something like that and you putz around at the starting line a decent pump and large enough fuel lines should be able to supply adequately the needs for most applications. My .02 cents flame away if you want to .... FED 387

Forget to turn the fuel pump on as you pull out of the lanes and do a burnout and see how far you get.

Hacksaw · 11-27-2019, 10:45 AM

Quote:

Originally Posted by Eman

Forget to turn the fuel pump on as you pull out of the lanes and do a burnout and see how far you get.

The engine quits before you finish the burnout. Been there.

FED 387 · 11-27-2019, 11:53 AM

Yes they might die doing a burn out you definitely need to replenish the fuel that is used by applying pressure to move fuel from the reservoir to the carb float bowl ---- I said the amount of fuel CONSUMED to do the burn out and run a lap--- You don't need a 500 GPH pump and humungous pressure to accomplish this ---you need an adequate supply--- Now what is an adequate supply ?? That is a case by case scenario that trial and error and experience and advice is going to help you determine the solution to the problem--- I suppose overkill in choosing your equipment will solve it right away but do you really need to spend that much money to reach your objectives--FED 387

gsa612 · 11-27-2019, 01:04 PM

The best bang for the buck would be an Aeromotive SS pump,has 18 lbs preset pressure.I run one on a BBC,Q-jet,1/2 in.fuel line stocker. Steady 6 1/2- 7 lbs.down the track...gsa612

Dissident · 11-27-2019, 01:39 PM

Regulated fuel pressure on a QJ at 5-5.5psi will supply enough fuel IF the n&s is sized correctly......pardon the digression...

Most if not all stock and super stock cars have the fuel supply sump (tank or cell) in the rear, so the system pressure must oppose g.....

Adequate Fuel Supply? The following chart is for gasoline.

In case you have forgotten, without data, you are just another guy with an opinion.

Regards to all that like this kind of stuff,

HB2

Dissident

11-26-2019, 07:15 AM	#11
Makinchips Junior Member Join Date: Apr 2016 Posts: 26 Likes: 0 Liked 3 Times in 3 Posts	Re: Fuel pump requirements Single Holley carb.

11-26-2019, 11:05 AM	#12
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 324 Liked 280 Times in 150 Posts	Re: Fuel pump requirements Take a moment and think about something! There is probably enough fuel in the float bowls on a Holley carb to do a burn out and make a full 1/4 mile pass before you run out of fuel at the 1/4 mile mark !!! How much fuel do you think is going to pass thru 4 little jets??? All you are trying to do is overcome the acceleration of the vehicle and keep an adequate supply of fuel going thru the carb to the engine--- Unless you have 600 inches or something like that and you putz around at the starting line a decent pump and large enough fuel lines should be able to supply adequately the needs for most applications. My .02 cents flame away if you want to .... FED 387

11-26-2019, 12:20 PM	#13
Makinchips Junior Member Join Date: Apr 2016 Posts: 26 Likes: 0 Liked 3 Times in 3 Posts	Re: Fuel pump requirements About 20gph at 520hp if i didn't screw the math up. 1/2 lb of fuel per 1hp i think? That's all fine accept the cust tells me it stops pulling around 6000 in high gear Last edited by Makinchips; 11-26-2019 at 12:34 PM.

11-26-2019, 02:00 PM	#14
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,318 Likes: 546 Liked 1,629 Times in 502 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	#15
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

11-27-2019, 11:53 AM	#18
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 324 Liked 280 Times in 150 Posts	Re: Fuel pump requirements Yes they might die doing a burn out you definitely need to replenish the fuel that is used by applying pressure to move fuel from the reservoir to the carb float bowl ---- I said the amount of fuel CONSUMED to do the burn out and run a lap--- You don't need a 500 GPH pump and humungous pressure to accomplish this ---you need an adequate supply--- Now what is an adequate supply ?? That is a case by case scenario that trial and error and experience and advice is going to help you determine the solution to the problem--- I suppose overkill in choosing your equipment will solve it right away but do you really need to spend that much money to reach your objectives--FED 387

11-27-2019, 01:04 PM	#19
gsa612 Senior Member Join Date: Jan 2008 Location: 100th Meridian Posts: 570 Likes: 116 Liked 280 Times in 139 Posts	Re: Fuel pump requirements The best bang for the buck would be an Aeromotive SS pump,has 18 lbs preset pressure.I run one on a BBC,Q-jet,1/2 in.fuel line stocker. Steady 6 1/2- 7 lbs.down the track...gsa612

11-27-2019, 01:39 PM	#20
Dissident Member Join Date: Jan 2016 Location: Colorado hills Posts: 123 Likes: 11 Liked 73 Times in 36 Posts	Re: Fuel pump requirements Regulated fuel pressure on a QJ at 5-5.5psi will supply enough fuel IF the n&s is sized correctly......pardon the digression... Most if not all stock and super stock cars have the fuel supply sump (tank or cell) in the rear, so the system pressure must oppose g..... Adequate Fuel Supply? The following chart is for gasoline. In case you have forgotten, without data, you are just another guy with an opinion. Regards to all that like this kind of stuff, HB2 Dissident Last edited by Dissident; 11-29-2019 at 01:39 AM. Reason: struggling with chart format..