ROCKAUTO FUEL TANKS
- Thread starter A/MP
- Start date
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I started to change to a 3/8" line for my 340, but read where 440 4 barrels came from the factory with 5/16" fuel lines. I doubt your 273, unless it is an extremely wild build, will benefit from a 3/8" fuel line. I'm certain my 340 won't.
I put the 3/8" sender in mine with the line to match. (just in case a 408 find's it's way under the hood someday)
The tank doesn't size the fuel line, the pick up you install does, could be 5/16 or 3/8. If you go with the 3/8, if you decide to go bigger engine it'll save you a job of changing pick up. You can adapt 3/8 P/U to the 5/16 lines. You can never have too much fuel at the carb, since it regulates how much you're going to burn. To take advantage of 3/8 P/U you have to change all the line to the fuel pump. Since a lot of guys have being doing F.I. the 3/8 line is a good thing. Just food for thought.
I'm not keeping the stock fuel lines. Since this build will be on the street from time to time I don't think I want a fuel cell. I have a 400 HP SB or a 550 HP BB for this build. I might just get a new tank and sump it and not worry about the pick up. I'd still have the sender for the factory gauge.
prorac1
Well-Known Member
Yep. We did the same thing with Jason’s car.
Rock auto tank and sender. 3/8” sender with one outlet and one return. In case we switch to a return style fuel system.
flingdingo
Well-Known Member
More volume is always better. Just ask The Who.
prorac1
Well-Known Member
5/16 will support 500 HP. That said we all know bigger is always better, right?
prorac1
Well-Known Member
I refuse to acknowledge your logic and reason and run 8AN fuel line on my 575 hp street car. Lol
But seriously though, I agree. Most of us oversized our fuel systems. Which I don’t see as a problem.
FWIW, that same 8AN line fed my 775 hp big block with out breaking a sweat.
Both naturally aspirated.
prorac1
Well-Known Member
3/8 will generally take you farther than most will ever go.
That's my general rule of thumb. Course now, there are exceptions to every rule. That twin turbo alloy headed 416 build lookin for 1500 HP probably needs bigger than 3/8. But that's the radicalness that it takes to need it. 3/8 will purt near supply whatever most guys will ever build. But lemmie get that -10 out. lol
prorac1
Well-Known Member
Lol. I actually run -10 to the pump and filters, than -8 to the regulator. Lol
Totally overkill.
But……we ran 11.12 @ 122 mph @ 3500 lbs with 3/8 line. Plugs looked beautiful. No fuel supply problems pressure wise either.
It's like a Dana 60 behind a stock stroke N/A 360. You know it's overkill, but it'll never give problems. Ever. Nothing wrong with overkill. It's just not necessary. That's why it's overkill. lol
prorac1
Well-Known Member
I am running a DANA 60 also. Lol.
I am actually thinking about cutting a Ford 9" down for the Valiant. I want something under it with a full 3" axle tube and I HAVE the 9". If I do it, I will even keep it small bolt pattern. lol
d55dave
Well-Known Member
With today's crap ethanol laced fuels vapor lock is a real problem. The engine driven fuel pump sucks fuel through the line, which makes it want to separate into vapor. A 5/16 will have much more resistance to the fuel pump and will create more vapor lock issues.
Over and above this, if you have any kind of hp and intend to run at wide open throttle through the gears the 5/16 is marginal at best. My somewhat mild 408 had fuel delivery issues at the top of second until I switched to a 3/8 fuel system.
Over and above this, if you have any kind of hp and intend to run at wide open throttle through the gears the 5/16 is marginal at best. My somewhat mild 408 had fuel delivery issues at the top of second until I switched to a 3/8 fuel system.
The ethanol thing is a good point but a good return system will have more effect than raising the diameter of the supply line, IMO. Doing both would probably be even better.
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