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what is the difference between HEI with or without a vacuum

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by zach78k5, Sep 15, 2004.

  1. zach78k5

    zach78k5 1/2 ton status

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    I have seen distributors both ways. is there an advantage to having the vacuum or is it crucial. any sort of explanation would be great. thanks.
     
  2. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    the hei with out vacuum is the ESC HEI. the computer controls the advance instead of the vacuum. the ESC is usually junk and i think should be replaced with the one with the vacuum.
     
  3. 84_Chevy_K10

    84_Chevy_K10 Banned

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    ESC still has a vacuum canister and has nothing to do with vacuum advance.

    ESC retards timing based on engine knock.

    Without a vacuum canister your fuel mileage will suffer. That's basically the only reason for vacuum advance.
     
  4. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    [ QUOTE ]
    ESC still has a vacuum canister and has nothing to do with vacuum advance.

    ESC retards timing based on engine knock.

    Without a vacuum canister your fuel mileage will suffer. That's basically the only reason for vacuum advance.

    [/ QUOTE ]


    ESC Electronic Spark Control. My buddies 82 C10 had a vacuum advance HEI with ESC. They both adjust timing for different situations, but as Tim stated they are not the same thing. We ended up bypassing the ESC by putting in a regular vacuum advance HEI distributor in (to be honest I didn't really notice any difference).
     
  5. 84_Chevy_K10

    84_Chevy_K10 Banned

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    [ QUOTE ]
    [ QUOTE ]
    ESC still has a vacuum canister and has nothing to do with vacuum advance.

    ESC retards timing based on engine knock.

    Without a vacuum canister your fuel mileage will suffer. That's basically the only reason for vacuum advance.

    [/ QUOTE ]


    ESC Electronic Spark Control. My buddies 82 C10 had a vacuum advance HEI with ESC. They both adjust timing for different situations, but as Tim stated they are not the same thing. We ended up bypassing the ESC by putting in a regular vacuum advance HEI distributor in (to be honest I didn't really notice any difference).

    [/ QUOTE ]

    The early 80s ESC doesn't, "Adjust" timing. It simply retards timing when it hears engine knock. It's not intelligent enough to do any more than that.
     
  6. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    [ QUOTE ]

    The early 80s ESC doesn't, "Adjust" timing. It simply retards timing when it hears engine knock. It's not intelligent enough to do any more than that.


    [/ QUOTE ]

    Hey RETARD (yes pun intended). Your INTELLEGENCE (yes pun intended) must be off.

    Last I knew retarding the timing was an adjustment. I did not state it was advancing or retarding just that it was adjusting.

    J/K Sorry Tim after seeing your title (ie Village Idiot) and reading your post I couldn't resist. I know you were just trying to clarify to make sure people didn't think vacuum advance and ESC were the same thing /forums/images/graemlins/thumb.gif

    The last thing we need on CK5 is name calling, people bashing, etc. but after all you have been through on this site, I just couldn't resist /forums/images/graemlins/whistling.gif

    I know you unlike others can take it, and hopefully nobody will be affended reading it. If you are, I'm sorry and will gladly delete.

    Chris
     

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