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SB400

Discussion in 'The Garage' started by Muddytazz, Jul 23, 2004.

  1. Muddytazz

    Muddytazz 1 ton status

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    People with them or have had them. With the knowledge of them being known for running a tad on the warmer side. Here is my thought and need opinions on it.

    I was thinking, why couldn't a person have the steam/water(whatever they are called)opened up bigger? Is there ever room to do this or would it even be worth it?
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    Don't know about opening up the passages, but I suspect the way gaskets are made anymore, it's not likely possible. If you could open up the holes in the gasket without weakening it, probably very little problem, but I also suspect GM made the cooling as efficient as possible, meaning the holes are already as large as possible for strength or gasket sealing, or are strategically designed to increase velocity or turbulence in certain areas.

    One thing I've done on the last couple of motors I've assembled, is "port" the water jackets with a carbide burr, at least as much as I can see and reach.

    Newer castings are much better (my Vortecs were extremely "clean") but a pair of 70's GM castings I had were absolutely horrid inside the water jackets. I could break off large chunks with a chisel and hammer, then smoothed them for flow.

    I guess without some sort of before/after test its impossible to know whether porting the water jackets works well or not, but it stands to reason that less turbulent coolant movement means better cooling. As bad as the early castings were, I KNOW it helped move coolant easier.
     
  3. 84_Chevy_K10

    84_Chevy_K10 Banned

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    The problem lies with the fact that there are no water jackets between cylinders on a 400 SBC, and this cannot be solved by modifying anything.
     
  4. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    [ QUOTE ]
    The problem lies with the fact that there are no water jackets between cylinders on a 400 SBC, and this cannot be solved by modifying anything.

    [/ QUOTE ]
    Yep, and boring out the steam holes would bring them too close to the cylinder walls and chambers.
     
  5. 4x4Freak

    4x4Freak 1/2 ton status

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    Get a good radiator and you shouldnt have a problem. I had the 400 in my K10 and it almost always ran about 180-190, even running 3k rpm down the highway. It would get a little warm if I was really revving it up while trying to get out of a mud hole. I know my radiator wasnt in the best shape though.
     
  6. hi pinion

    hi pinion 3/4 ton status

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    I dunno man, but that 400 you have is one of the meanest motors ive ever heard /forums/images/graemlins/peace.gif
     
  7. Corey 78K5

    Corey 78K5 1 ton status

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    A 4 core radiator, high volume water pump and an oil cooler would probably keep things in check.
    I just scored a 400 Myself. Still has the standard bore and everything turns over no problem /forums/images/graemlins/waytogo.gif /forums/images/graemlins/waytogo.gif
     
  8. Mreetz

    Mreetz 1/2 ton status

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    I'm goin with a rebuilt 400 now, did all that was mentioned here and will add fans to the radiator.

    Marty----
     
  9. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    [ QUOTE ]
    I'm goin with a rebuilt 400 now, did all that was mentioned here and will add fans to the radiator.

    Marty----

    [/ QUOTE ]
    I have had some porpblems but basically have them solved. I have a new 4 core, high flow pump, 180 stat, and dual electric fans. I have the flex a lite part number 295 fan setup. PUlls 4600 CFM, has an A/C relay and comes with everything needed for the install.
     

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