Cliff's Quadrajet Parts and Rebuild Kits
General Category => Quadrajet Carb Talk and Tips => Topic started by: F250 Restorer on December 14, 2012, 09:55:42 AM
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Because I have an inline 6, Ford 300, with a dual port intake, the front of the carb faces the v.cover on the passenger side. I am running a front inlet QJ, 17059272, and there is not room for the oem fitting/housing w.filter. What I have found with two autolite 4100's is that when I delete the oem screw in filter in the front of the carb, fuel gurgles past the needle seats. I have only 4.5 psi fuel pressure. No matter how the floats are set. Yes, vitron tips. I have tested with multiple needle seat combos. Two carbs. So, I conclude, the oem filter on the 4100 acts as a psi reducer/regulator. Yes, I know it should handle 4.5 psi. I know that most Holley's say they can handle up to 8psi. But...the 4100 can be run without the airhorn, and fuel is gurgling past the needles.
Question: Does the oem filter on the QJ also reduce fuel psi into the carb? I guess I would see signs of flooding if that were the case.
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There are short filter housings that fit that carburetor.
The filter has no effect on pressure to the needle/seat assembly.
That carburetor will EASILY take 8 psi with a .135" fuel inlet seat with zero issues anyplace.....Cliff
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fuel gurgling sound likes its boiling in the lines to me.. been there a few times myself it can happen before or after the pump dont matter it will unseat the needle and if its hot enough will empty the lines and really poor fuel into the butterflys.. remember gas boils around 155 Fahrenheit dont take much to get there if anythings close.
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That has to be the problem, boiling in the lines. I have a solid line running 6" above the headers. The throttle on the carb gets so hot I can not work it with my hand.
I have to get a thermometer gun to find out how hot it gets. Any suggestions?
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I'm using a craftsman brand IR gun that works pretty well. It also includes a laser pointer to help you isolate what you're aiming at.
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quick and easy help is thermal tape but its not a 100% fix. we use it alot in racing around fuel lines. alot of different brands out there and sometimes local auto parts stores will carry some