Coolant circulation troubleshooting

Discussion in 'Troubleshooting & Diagnosis' started by pomartin, May 4, 2021.

  1. pomartin

    pomartin Veteran Member Gold Member

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    Dear all,

    I need your advice.
    I'm finnishing my top-end refresh on sbc383 (heads done, lifter change, pushrods, blower servis...).
    Today the engine started- i tried it without thermostat- to ensure filling up with water.
    I did not vent the cooling system during head assembly.

    I noticed that outgoing tube was empty- nothing coming out of it after a while of running.
    I did not rebuild the water pump, but it was "dry" for almost half a year, installed on a block.
    Checking with endoscope shows nothing visibly wrong from the inside...

    Is it possible that I'd need to vent water pump somehow, before it starts pumping water?
    What else should I check?

    Many thanks,
    M
     
    Last edited: May 4, 2021
  2. Coadster32

    Coadster32 Veteran Member Lifetime Gold Member

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    Little confused by this. I am assuming by this statement that you filled the radiator, but not the engine block, and are expecting the water pump to top off the system?

    Don't think I understand this either. Perhaps I'm out of my element, as I've never worked on a blown motor before. I hope someone with better knowledge chimes in.
     
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  3. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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    I'm assuming there's just not enough coolant/water in the system. Did you fill the radiator or just the block?
     
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  4. pomartin

    pomartin Veteran Member Gold Member

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    Thank you both for reply.

    First I had working machine.
    Then I disconnected radiator from pump pickup line, lifted engine,... (there was some work on bottom end also).
    With pump disconnected from radiator I removed heads.
    During dosasembly water went out of engine, naturally.

    Then I lowered engine back, connected radiator to pump and mount heads and other top end components.

    Then I only filled radiator to the top and fired up the engine.

    I hope this makes it more clear of what I did or did not do.
     
  5. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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    Ok - the engine sucked in the water from the radiator, you just need to add more through the radiator cap. Once the radiator is full again, start the car and continue adding to the radiator as it goes down. The whole system holds ~22 liters of fluid - it's A LOT more than it seems like
     
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  6. pomartin

    pomartin Veteran Member Gold Member

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    Oh my... It looked like a lot less when it poured out at dissasembly.
    I'll try to pre-fill the block through thermostat mounting bracket to avoid running engine without coolant inside.

    Many thanks for your help! Much appreciated.

    Regards,
    M
     
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  7. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    Your 383 (sbc) has the same coolant capacity as a 350.
    A factory small block V8 system is about 16 quarts or 15 liters.
    (Radiator, engine block, hoses, heater core & overflow tank.)
     
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  8. COPO

    COPO Veteran Member Lifetime Gold Member

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    The block holds a poo load of water. Whenever I flush the system I always drain the block, then add my 50/50 mix. Some people just do a flush then leave the plain water in the block then they wonder how much 100% antifreeze to add.
     
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  9. pomartin

    pomartin Veteran Member Gold Member

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    Dear all,

    once again thank you all for your input.
    After I "vented" the pump through thermostat bypass hole (which was previously plugged) the coolant can now be transferred through the engine when water pump is in motion.
     

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