Fuel Filters DO make a difference!!!
Le Mans Master
Joined: May 2000
Posts: 6,493
Likes: 6
From: Bloomington MN
Cruise-In II Veteran
Re: Fuel Filters DO make a difference!!! (Smokehouse69)
Hey! I just noticed you got your original name back! :cool: I just wanted to say that if you are running a stock 69 L46 (or ZQ3) air cleaner assembly, a Holley 650 DP should fit fine. I actually ran a cast iron GM dual plane that was more of a high rise (like a cast iron version of the LT-1 manifold), and still fit the Holley (actually, mine was a 750) in there with a small block hood. It also fit with an Edlebrock Performer. What intake are you running?
AC
[Modified by A C, 4:05 PM 8/20/2001]
AC
[Modified by A C, 4:05 PM 8/20/2001]
Drifting
Joined: Nov 2000
Posts: 1,390
Likes: 39
From: North Brunswick NJ
Re: Fuel Filters DO make a difference!!! (A C)
I know that most of the Holley equiped cars did not have a return line; four barrel as well as 3x2. It may have to do with the fuel pumps ability to feed the carbs at high rpm and not have the return bleed off pressure. Any one else with a thought on this.
Ed
Ed
Le Mans Master
Joined: Mar 1999
Posts: 6,744
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From: delmont pa
Cruise-In I Veteran
Cruise-In II Veteran
Re: Fuel Filters DO make a difference!!! (ED DINAPOLI)
a return line would have saved a lot of 435-427 engines because these had carb bleed through that caused the gas to get into the oil and cause bearing failure. the return line relieves the fuel pressure between the pump and the carb. this was the reason that the return was used to prevent excess pressure to the carb and cut down on emisssions. if you use a return line system you need a higher pressure fuel pump because that the return line is a calibrated leak. a trick you can use if your pump goes weak is to clamp off the return line to increase the fuel pressure.
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
Re: Fuel Filters DO make a difference!!! (clem zahrobsky)
Clem, I have been told (and all I know is what I have been told!! ) that the pressure relief aspect of the fuel return line was needed at idle, ie that the fuel pump would pump more gas than was needed at idle, but was not needed at higher rpm. Of course nobody explained how the fuel filter stopped bleeding off fuel at higher rpm!
Ed, I was asking about the 71 LS-6 configuration earlier, and apparently that was one Holley equipped engine that did use the fuel return line. Would that be the only one? MJ
Ed, I was asking about the 71 LS-6 configuration earlier, and apparently that was one Holley equipped engine that did use the fuel return line. Would that be the only one? MJ
