Timing affect on engine temp

Discussion in 'Engine Topic' started by sponge003, Jun 3, 2009.

  1. sponge003

    sponge003 Veteran Member Gold Member

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    Jan 10, 2009
    Concord, NC
    What general affect does changing the timing have on your engines running temperature?

    If you increase your timing (from 32 to 36 for example) will your temp increase or decrease?

    Thanks
     
  2. XxWickedz28xX

    XxWickedz28xX Veteran Member Lifetime Gold Member

    5,979
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    May 22, 2001
    Carmel, NY
    I just went through this myself, and the fellas here set me straight, so im happy to pass along help.

    My timing was off, it was about 8 at idle...car would run odd, and hot. Bumped the timing up to 14...car ran better, and cooler. So, for my setup, the more timing I gave it, the cooler it ran.
     
  3. sponge003

    sponge003 Veteran Member Gold Member

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    Jan 10, 2009
    Concord, NC
    Going to move timing @ idle from 11 to 15

    COOL
     
    Last edited: Jun 3, 2009
  4. TheStig

    TheStig New Member

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    Jun 1, 2009
    Redding, Ca
    Set initial at 12* shoot for a total of 34-36*. Limit the amount of vac advance to 8 crankshaft degrees and run it on manifold vac. This will give about 20* of timing at idle but will keep the total advance safe while under throttle. I have mine set up this way and I will never change back.
     
  5. Todd80Z28

    Todd80Z28 Moderator Staff Member Lifetime Gold Member

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    Jun 11, 2002
    Northern VA
    The amount of vac advance is highly dependent on the engine config. 8* might be safe, but you may be leaving a bit of part-throttle response and fuel mileage on the table with so little.

    I run almost 20* vac advance myself, on top of 10init, 34 total, but I have a fairly mild, 9:1 350 with aluminum heads and poor quench.
     
  6. hhott71

    hhott71 Veteran Member Lifetime Gold Member

    14,371
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    Mar 30, 2001
    Joplin Mo. 64801
    it depends.

    32º is usually way too retarded to get the proper burn in a typical SBC.
    Too little timing and Too Much timing can have bad effects.

    Depending on the Cam, Compression, Piston, Chamber, Fuel, Operating range, and a few more factors, 34º-44º may work best, and of course light loads will want even MORE timing and that is where the vacuum advance is used, adding 10º or more.
    The vacuum advance works best when connected to ported (or part-time) vacuum source, that is why the port is there. Having 10º extra vacuum advance timing at idle makes the engine idle faster, it also loses that advance and gets stumbly when that timing disappears, or can cause extra ping on light acceleration. ALSO too much timing ruins the sparkplugs, glazing and overheating etc.

    Strive for 10-16º initial, 20º-30º centrifugal and 10º or so vacuum advance.
     
  7. sponge003

    sponge003 Veteran Member Gold Member

    1,511
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    Jan 10, 2009
    Concord, NC
    I do not have vac advance, mechanical only.

    This is strictly a track car right now.

    I was running 32 total for the initial break in and first runs and am going to 36 total based on what we saw for times. might end up at 38 but we will wait and see.
    The motor was getting a little warm ~210 running 2 classes and I was curious if changing the timing would help with this or add to the problem.
     
  8. TheStig

    TheStig New Member

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    Jun 1, 2009
    Redding, Ca
    If its a track car only I would lock it at 36*

    As far as the vac advance debate goes people will allways have thier opinions. I made the switch to manifold vac with great results and I will not change it back. My motor runs better, cooler, and way more responsive than it did on manifold vac.
     
  9. Simon@London

    Simon@London Veteran Member

    1,244
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    Feb 16, 2009
    London Ontario
    ???? so are you running port or manifold now. I have set my street up to 14/36 now and it runs fine.

    hhott71 on this stock bottom end motor, Crane street Cam, flat tops, vortec heads is this a good timing range. You remember I don't run any Vac advance ( noise so that is dead issue )

    idles at 14, all in at 36. Motor runs cool and exhaust seems to smell cleaner.
     
  10. Todd80Z28

    Todd80Z28 Moderator Staff Member Lifetime Gold Member

    10,800
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    Jun 11, 2002
    Northern VA
    100% agreement on that.

    If this is just a track car, then it's unnecessary, though. Vac advance does nothing at WOT.
     

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