what size fuel line

Discussion in 'Competition Camaros' started by camaro454, Aug 3, 2003.

  1. camaro454

    camaro454 Veteran Member

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    Ive got a 468ci big block im putting in my camaro. I plan on putting anywere from 125 to 150 shot on it would 6an fuel line be big enough?

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  2. rscamaro73

    rscamaro73 Administrator Staff Member

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    Best bet (from my research) is at LEAST 1/2" line in, and a seperate fuel system for the nitrous. 1/2" would be minimum for a decent street BBC, and then a shot of juice would be on the farther edge of safety.


    This a street car of a 'pro-street' concept ? If it is OTHER THAN street only, I'd go 5/8" to 3/4". Big, but no restrictions.

    http://www.centuryperformance.com/fuel.asp
    Here's some good info to go off of....


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    " Come to the Dark Side....the BBC force is STRONG within us all...."

    73 LT 454 and a small touch of giggles....hee hee hee. More good parts are lining up the shelves.....
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  3. SCOTT CORBETT

    SCOTT CORBETT Veteran Member

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    In my opinion Id use 3/8 for the engine and a seperate 3/8 system for the nos. I run a 468bb and its feed with 3/8 line, no nitros.
    If you want to use 1/2 line then a holley blue will not do. You then must increase the pump size. Ive read that "tech" on a 1/2 fuel line increases surface area,g-forces etc. so the holley just cant cut it.
    I shift mine at 6000, and am only using a stock fuel pump on the engine, just a cheap $20 pump. My holley blue died and had to get it towed.
     
  4. SlowSBC

    SlowSBC Veteran Member

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    Spend the extra money on a single pump. List of advantages of a single pump over a double pump setup

    2 pumps weight more than one
    2 pumps need 2 times the fittings and hose
    2 pumps are heavier
    2 pumps take up more room
    2 pumps draw more amprage
    2 pumps need 4 filters
    2 pumps 2 times the problems

    On a 2 pump system if your motor pump goes bad or blows a fuse, your NOS pump will continue to run. On a pass that one pump is enough to make the rest of the 1/4 mile. Only problem is it used your piston for the missing fuel. On a one pump system your car dies.

    I have used both systems. I used 2 BG 400 to run the motor and one to run the NOS. There was a pressure drop off the launch with both pumps. I upgraded the spring in the by-pass to increase the pressure to 32 PSI (was 18PSI) and the pressure loss was gone. I then removed on pump and use a single pump for the motor and 2 foggers (300 HP and 250 HP setting). The data showed to be the same with both systems. I have a data logger so this was not guess work.. Hope this helps someone and this is only my opinion..

    But anyway to your question. Run a -12 to the inlet of the pump. Out of the pump run a -10 line to a Y-block (not a T-fitting). The Y-block will have a -10 in and two -8 outs. Run the -8 to Y-block (-8 in and -6 out) for both the NOS and Carb. This setup will be more than enough for you to upgrade on without all the plumbing. Remember to run 2 regulators. One for the motor and one for the NOS. Use a 12" filter if possible. You should use one before the pump and one after. If you can not put one before the pump, filter your fuel before putting it in the tank. But you MUSt put one after...Hope this helps...
     
  5. jakeshoe

    jakeshoe Veteran Member Lifetime Gold Member

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    3/8" line is enough to feed a healthy 468.
    Usually the pump is the bottleneck. A stock mechanical pump won't feed my mild 427. It will COMPLETELY run out of fuel about halfway through 3rd gear.

    1/2" is good insurance but not necessary and as stateed previously, 1/2" does no good without the pump to push it.

    Think of it this way,
    The orifice hole for the needle and seat is what, .150" max on a typical carb.
    You might have 2 of these on a dual feed carb.
    The area of a 3/8 line is bigger than 2 large needle and seats by over 25%.
     
  6. SlowSBC

    SlowSBC Veteran Member

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    " Come to the Dark Side....the BBC force is STRONG within us all...."


    Hey RS, aint us Small Block guys beating up you Big Block guys on the net race???? LOL [​IMG]

    Here we go again........
     
  7. Fast72RS

    Fast72RS Veteran Member

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    I am not getting between you guys on this...but I like it BIG...just could not help...
    But I would recommend "Slow's" setup. I took it from him last year, running a 460 PE single pump and loving it. The only difference is I use only one y-block (10 in, 2x8 out), one to carb regulator, one to n2o regulator. Prety much as he said. I think this way I never will have to worry (about fuel) no matter how big shot.
     
  8. stangslayer

    stangslayer Veteran Member

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    What do you do with the other side of the first y-block (-10 in and two -8 out)? wouldn't it be just as easy to just use one y-block?


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    black 76 camaro
    vortec 406sbc
    419HP/473TQ (so says EA 3.0)
    13.13@102.2 and dropping
    60' around 1.85
     
  9. SlowSBC

    SlowSBC Veteran Member

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    Well my set up was for a dual carb and 2 stages. Sorry I didnt say that. You will only need one Y-fitting if you run one carb one stage of NOS(-10 to (2) -8 Y-fitting). Each -8 will run to a regulator From there one to your carb and one to the nitrous. Sorry for the missing information.. Hope this helps... [​IMG]
     

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