It's just about time to start plumping my fuel system, and I'd like some suggestions.

I've got a 454, stock stroke, 12.7:1 compression, Lunati solid 259/267, .625/.625, 110, GMPP aluminum heads, 2.19/1.88 valves. Running a 950HP. It should put out around 600 HP.

The pump is a Mallory Comp250, Mallory Comp 500 filter, and Mallory 3 port regulator.

I'm leaning towards the 1/2 aluminum fuel line for the frame, and -8AN from the cell to the hard line, and from the hard line to the regulator. From there I'm thinking -6AN to the carb.

Does this sound appropriate, or do I need to bump up to 5/8" hard line, and -10AN?

Here's a little help:

http://www.centuryperformance.com/fuel.asp

You can use 1/2" line to the regulator, but the return line will want to be 5/8" due to the volume of the pump. If the return line is too small, your fuel pressure will be erratic.

Great Site!

Thanks a great site, I've bookmarked that site. Do we have any real world experience and opinions out there? -8AN or -10AN?

Anyone else have suggestion?

Sean,

I would use -10 from the cell to the pump. 1/2" hardline (or -8)from the pump up to the front. I like to keep the line size fairly large before the pump as most electric pumps are essentially gravity feed.

On this same subject, I saw something very interesting while a Reher-Morrison a couple of weeks ago. Every dyno carb they had on the shelf outside the dyno has -6 feed lines going to each fuel bowl. This is on 1000-1300 HP stuff.

Good Luck,

That's not a bad idea, though I hadn't ever considered it, Jason. I was thinking of the -6AN to carbs, though, that's pretty standard. Wild to think so much HP through those little itty bitty -6AN lines would even work. :confused:

How big do you think the needles and seats are on those carbs? Do you think they present more of a restriction to the flow than the -6 line? There are also 2 carbs on these engines. Our 331" road race motor makes about 430 hp using a 2-bbl carb with a single -6 line feeding the carb.

I have used both and they both work but -10 is easier to run and work with although the price isn't as friendly.

Originally posted by DragRacer:
Sean,

I would use -10 from the cell to the pump. 1/2" hardline (or -8) from the pump up to the front. I like to keep the line size fairly large before the pump as most electric pumps are essentially gravity feed.

On this same subject, I saw something very interesting while a Reher-Morrison a couple of weeks ago. Every dyno carb they had on the shelf outside the dyno has -6 feed lines going to each fuel bowl. This is on 1000-1300 HP stuff.

Good Luck, I agree 100%. A single -6 will be too small unless you are running two separate -6 lines to the front a rear bowls from separate ports on the regulator.

I found that on my approx 500 HP small block a single -6 line, 3/8" steel line, and stock 3/8" pickup was too small to maintain pressure with a Carter 172 gph mechanical pump. The fuel pressure was dropping down to 2 psi at WOT

I ditched my entire old system and went to a 1/2" pick up, Aeromotive 150 gph electric, 1/2" aluminum hard line, and a single -8 braided from the regulator to the carb. Pressure is a rock solid 7 psi whether idling or WOT. A little more fuel pump and the -10 pick up should do the trick for 600 HP IMO

I have -8an fuel line, 1/2" pickup (stock tank, no sump), Mallory Comp 140 pump and a two port non return style regulator. Engine is making right at 700hp. I have 8psi at idle and 7psi WOT though the traps. If you decide to use a return stlye regulator you should consider running a return line that is SMALLER than the supply line. I realize in theory that a larger return line is recommended, but I think you will find in practice this is not always true. You need some pressure on the return side of the regulator to keep the fuel column/pressure up on the supply side. My friend's SS car launches with a 1.31 60'. He originally had his fuel system -10 supply and -12 return. His Kwick Data acquisition system was showing a fuel pressure drop at launch from 9psi to 2psi. He reversed the supply and return lines and the problem went away. Food for thought....

How big was the fuel pump on the SS car?

Originally posted by onovakind67:
How big was the fuel pump on the SS car? 500GPH

i don't know about all the fancy fuel system stuff but haven gone 10.30's in a 65 chevelle with 1/2" line and holley blue pump(110 gph) with a dead head regulater. mike