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Mercruiser 454 Fuel pump?

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  • Mercruiser 454 Fuel pump?

    I am building basically a 454 420 magnum motor with bumped compression and a holley 800. I am switching from a gen IV motor to a gen V so i cannot use my old block mounted mechanical fuel pump. Gen V does not have provisions for the mechanical pump... so im wondering what my best option here would be for an electric fuel pump setup?

    Right now i am thinking either holley black with a return style regulator or a Aeromotive 11211 marine fuel pump with return style regulator. Both these pump claim about the same specs - 140 GPH at 14 PSI. WILL THIS BE ENOUGH?

    What PSI should i regulate down to?? Ive read that 7 PSI is about all the float needle in the carb can regulate.. SO should i set the fuel pump at 7 PSI at wide open throttle?? but then wouldnt it flood out all the time except when im at WOT?? Im a little confused about how you should set it?

    Anyone have any thoughts?

  • #2
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    Re: Mercruiser 454 Fuel pump?

    Originally posted by sparky774 View Post
    I am building basically a 454 420 magnum motor with bumped compression and a holley 800. I am switching from a gen IV motor to a gen V so i cannot use my old block mounted mechanical fuel pump. Gen V does not have provisions for the mechanical pump... so im wondering what my best option here would be for an electric fuel pump setup?

    Right now i am thinking either holley black with a return style regulator or a Aeromotive 11211 marine fuel pump with return style regulator. Both these pump claim about the same specs - 140 GPH at 14 PSI. WILL THIS BE ENOUGH?

    What PSI should i regulate down to?? Ive read that 7 PSI is about all the float needle in the carb can regulate.. SO should i set the fuel pump at 7 PSI at wide open throttle?? but then wouldnt it flood out all the time except when im at WOT?? Im a little confused about how you should set it?

    Anyone have any thoughts?
    Howdy,


    The pump on my 1997 model 454 mounts to the Bravo raw water pump drive. It's not my favorite way to do it but it works.

    I would use a marine type electric pump if I had to change mine. .......make sure you incorporate a provision to stop the pump when the engine stops running (like an oil pressure switch to operate the pump)

    You probably need to check with Holley tech support but most carburetors don't need more than about 6 psi or so. You'll need a regulator to throttle it back to no more than 6 or 7 psi.


    Cheers,


    Rick
    1987 FourWinns 211 Liberator, Originally an OMC 460 King Cobra.
    Re-powered in 2006 with a 1997 Mercruiser 7.4L Bravo III

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