Fuel education

Discussion in 'Race 400/430/455' started by BuickGSrules, Aug 6, 2018.

  1. BuickGSrules

    BuickGSrules Gold Level Contributor

    I need some education in fuel pressure and know you guys can help.

    I run a Tanks inc stock setup with in tank pump - it is the GPA-4 pump 255 Liters pr. hour/69 gallon pr. hour, I run it with a fuel regulator with return line. I am of course worried that the setup can deliver enough fuel. The pump is rated to 630 hp, but I have a stocker motor that donĀ“t put out any more than 450 max.

    I have read/heard that a fuel regulator with return line is better than a dead head regulator, and therefore I should not worry about the gph delivery.

    Can you tell me the difference and will the setup I have be enough to support my motor?
  2. hugger

    hugger Well-Known Member

    255 will handle 450hp with no issues whatsoever, and yes a return system is superior in every way to a deadhead.
  3. BuickGSrules

    BuickGSrules Gold Level Contributor

    Thanks - I hoped you would chime in.
  4. hugger

    hugger Well-Known Member

    I assume it's a carb setup ?
    But to answer your other question regarding the deadhead vs return, the return will provide longer pump life, cooler fuel and is just more efficient in general...run at lower psi to work with the carb, it's possible to maybe be on the ragged edge at 69gph,..stock stage 1 pump is rated at 45 iirc, I may be way off but that number sounds familiar,..and can have trouble keeping up at the 400hp mark depending on elevation, rear gearing, load etc.I may would consider a 340L pump it will be a direct replacement and will give you some extra insurance, make sure you are using a hot wire setup to ensure full voltage
    Last edited: Aug 6, 2018
  5. Bens99gtp

    Bens99gtp Well-Known Member

    With a a return system you are always having fuel flow going through the pump, the fuel actually acts like a coolant to keep the pump cool. Plus you don't get any pressure drops or spikes with a return system as long as the pump is big enough. Mine sits at 8 psi at idle and 8 psi going almost 6500 through the quarter mile.

    With a deadhead once pressure builds the amp draw goes up cause the pump is a trying to push the fluid with nowhere to go. This builds a lot of heat in the pump. Plush your forcing the vanes to go through with that push pressure on them and will get a cavitation to start inside the pump.

    We built a truck with a 650hp 502 using a 340 pump plenty of fuel for it. Your 255 for 450hp is about the same volume ratio

    BQUICK Well-Known Member

    So my 250 Mallory is not enough for 650hp?
  7. hugger

    hugger Well-Known Member

    That's 250gph , 255liters per hour is much different, that 255 is at a much higher psi too
  8. Bens99gtp

    Bens99gtp Well-Known Member

    I hope so...I have a bg 280 and going to be in the area of 750hp. But in liters it's close to 1050 lph
  9. BuickGSrules

    BuickGSrules Gold Level Contributor

    Thanks for your input guys.
    I know that I eventually will step up to a pump that can move more fuel, and they have direct replacements for that. I will need that for the 482 going in.
    Yes, I run a Qjet carb, and have the pressure set at 5,5 psi.
  10. Robs455

    Robs455 Well-Known Member

    Your pump delivers 71 gph @12V and 79 gph @ 13.5V thats plenty for your engine. Your weak point are the small fuel lines, you should go with 1/2" supply and return.
  11. BuickGSrules

    BuickGSrules Gold Level Contributor

    Lines are upgraded both supply and return - but for the stock look I run the steel line to carb down from the dummy stage 1 pump - may need to upgrade that one too. Thanks for the input.
  12. Rob Ross

    Rob Ross Well-Known Member

    When I read up on Tank Inc, I recall the lowest pressure pump they offer is around 45 psi. If so, your return will need to be one size larger than your supply. I opted to not go with Tanks because of that.

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