braided line sizing ???

Old 09-05-2010, 06:26 PM
  #1  
davesnoscoupes
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Default braided line sizing ???

Car is a carbed 306, sumped tank and holley blue pump and reg for motor.

I'm having a few issues on hard accel. where the fuel press will drop to nothing before the end of the track, seems like the fuel cant keep up.

Right now it has -8 AN from the tank to the pump/filter, then -6 AN out from the pump to the reg. and -6 AN from the reg to the carb.

I was told that my -6 AN line from the pump to the motor may be to small to feed the motor at higher RPM.

thinking about upping the size of the line to -8 AN from the pump to reg but keeping the -6 to the carb.

So my question here is about the line from the tank to the pump, do I need to switch that line out to a -10 to feed the pump or can it stay the same size as the line out?

Oh and no return line is used.

thanks
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Old 09-05-2010, 08:38 PM
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spib
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what is your fuel pressure set at? can you see the gauge when you are running?

I used to have your set up on my 355, had pressure at 7.5 lbs no problem

have same blue pump on new motor, over 600hp have 8an to pro system reg and reg is on 8an line into carb, have pressure set at 8lbs, and that also works good for me
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Old 09-05-2010, 09:57 PM
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TheRabbit
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I feed my little motor with a 10 from tank to pump, 8 to reg. then 2 6's to the carb.
Make sure you don't have a clogged filter or an other problem. Take the line loose and let it pump into a bucket / can to check it.
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Old 09-06-2010, 07:43 AM
  #4  
chevyart
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Default fuel lines

i have the exact same setup as the rabbit in my 67 nova. car comes through the traps at 7700 rpms and never misses a beat art
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Old 09-06-2010, 02:01 PM
  #5  
markdunlap
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Default braided line sizing

If it were me I would just change the pressure side of the line from the pump to the regulator to #8 and leave the rest alone. If pressure still drops, then I would change that blue Holley pump out with something more modern with 250-350 GPH rating.
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Old 09-17-2010, 03:26 PM
  #6  
Scooterz
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Originally Posted by TheRabbit
I feed my little motor with a 10 from tank to pump, 8 to reg. then 2 6's to the carb.
Make sure you don't have a clogged filter or an other problem. Take the line loose and let it pump into a bucket / can to check it.
Ditto on above... but one carb. Something sounds fishy, but not necessarily the AN/size @ 6AN. I wonder about that spring/check valve thing in the Holley Blue... I have heard of those going south??
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