CLASS RACER FORUM - View Single Post - fuel pump w/q-jet

Grant Eldridge · 01-01-2008, 06:05 AM

Kevin,
We've found that the Q-Jet carb requires a far larger fuel system than a similar sized Holley carb, due to the fact that it has only one needle and seat and a single small fuel bowl. You need lots of volume available to the carb, so we've oversized the entire system.
If you're using a stock tank like we are, fabricate a new pickup tube and a return line fitting back into the tank to match the sizing of your new lines, replacing the oem tubing used originally. We use 5/8" aluminum line which is equivalent to AN-10 and run through a high flow inline Magna Fuel filter to a 300 gph Magna Fuel pump, then to a large Aeromotive return style regulator up front. At the time, Magna Fuel did not offer the return style of regulator, although that may now have changed. The return line should be the same size back to the tank. You must remove the bypass fitting from the pump and install the correct style of plug in it's place if you are using a return regulator and return line coming back from the motor. Important note :- you must also provide for a large vent for the tank of appropriate size, I used 1/2" venting here with one coil in the vent line to which I added a small canister filter. We run AN-12 line from the regulator to the carb and make up our own special inlet fitting so the carb has an instant reserve of pressurised fuel available in that oversized line. This system will pump a gallon of fuel in about 15 seconds free flowing. We find the fuel pressure remains constant throughout the run using this system, and the return system is easier on the pump with fuel constantly moving through the lines. I believe the pump also runs cooler, is less likely to aerate the fuel, and probably draws less amperage from your electrical system. It's quieter operating and likely will also last longer before requiring maintenance.
We started out a few years ago with 1/2" lines, Holley blue pump and regulator, then upgraded to a Holley black pump, then to the Magna Fuel pump with a deadhead style Magna Fuel large regulator and kept chasing fuel delivery as a possible problem. Do yourself a big favor, do it once. Spend the time and money once and use all the best stuff you can get first, you'll save money time and frustration in the long run and the system will be troublefree and adequate. I did it all the hard way, maybe my experience with this system can save you from going that way, Just my own opinion though.......smile...

01-01-2008, 06:05 AM	#3
Grant Eldridge Member Join Date: Jul 2007 Posts: 124 Likes: 0 Liked 0 Times in 0 Posts	Re: fuel pump w/q-jet Kevin, We've found that the Q-Jet carb requires a far larger fuel system than a similar sized Holley carb, due to the fact that it has only one needle and seat and a single small fuel bowl. You need lots of volume available to the carb, so we've oversized the entire system. If you're using a stock tank like we are, fabricate a new pickup tube and a return line fitting back into the tank to match the sizing of your new lines, replacing the oem tubing used originally. We use 5/8" aluminum line which is equivalent to AN-10 and run through a high flow inline Magna Fuel filter to a 300 gph Magna Fuel pump, then to a large Aeromotive return style regulator up front. At the time, Magna Fuel did not offer the return style of regulator, although that may now have changed. The return line should be the same size back to the tank. You must remove the bypass fitting from the pump and install the correct style of plug in it's place if you are using a return regulator and return line coming back from the motor. Important note :- you must also provide for a large vent for the tank of appropriate size, I used 1/2" venting here with one coil in the vent line to which I added a small canister filter. We run AN-12 line from the regulator to the carb and make up our own special inlet fitting so the carb has an instant reserve of pressurised fuel available in that oversized line. This system will pump a gallon of fuel in about 15 seconds free flowing. We find the fuel pressure remains constant throughout the run using this system, and the return system is easier on the pump with fuel constantly moving through the lines. I believe the pump also runs cooler, is less likely to aerate the fuel, and probably draws less amperage from your electrical system. It's quieter operating and likely will also last longer before requiring maintenance. We started out a few years ago with 1/2" lines, Holley blue pump and regulator, then upgraded to a Holley black pump, then to the Magna Fuel pump with a deadhead style Magna Fuel large regulator and kept chasing fuel delivery as a possible problem. Do yourself a big favor, do it once. Spend the time and money once and use all the best stuff you can get first, you'll save money time and frustration in the long run and the system will be troublefree and adequate. I did it all the hard way, maybe my experience with this system can save you from going that way, Just my own opinion though.......smile...