Harmonic balancer sizes?

Discussion in 'Engine Topic' started by jayfire, Jul 26, 2010.

  1. jayfire

    jayfire Veteran Member

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    Jun 26, 2008
    dayton, nevada
    What are the pros and cons with the different sizes of balancers? I have one 350 with an 8" balancer and one with a 6.25" chrome balancer. Would my little chrome timing pointer work on the little guy? Is the little guy ok to run as a daily driver or should I switch to the 8"? Thanks
     
  2. frankz

    frankz Veteran Member

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    Aug 24, 2009
    Illinois
    The larger mass of the 8" balancer is better at canceling crank harmonics which increase w/stroke size---prolonging crank life.The smaller balancer is better for acceleration w/less weight and smaller OD.
     
  3. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    Nov 4, 2004
    Ringgold, GA
    Look back at what Chevy always put on their high performance small blocks; the 8" one. That should tell you something.

    If you're in a drag race only engine, then a smaller one will work because the engine is in a constant acceleration/deceleration mode and will not see harmonic resonance like a street engine will from a constant rpm.

    Rule of thumb for a street - street/strip engine; the largest one you can get...
     
  4. procharged_z28

    procharged_z28 Veteran Member

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    Jul 20, 2009
    Houston,Texas
    So a 6.25 wouldnt be good for the street?
     
  5. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    Ringgold, GA
    I didn't say that... Most sbc have the smaller one, Chevy put the 8" units on their factory high performance engines. You can figure it out from there. IMHO
     
  6. procharged_z28

    procharged_z28 Veteran Member

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    Jul 20, 2009
    Houston,Texas
    ^^^Yeah true i was just asking for an opinion i can get a new 6.25 tci rattler balancer for 100 wanted to know if it would be any good?
     
  7. CamaroMan79

    CamaroMan79 Veteran Member Lifetime Gold Member

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    Jun 10, 2001
    Selah, WA
    I have always ran 6.25" balancers on my performance sbc's without any issues. The mild 350 I have in my truck has 85k on it and still running strong.

    Now thats not to say that an 8" balancer isn't a good choice as well. 'Im just saying that I have never had problems with the smaller diameter ones.
     
    Last edited: Jul 27, 2010
  8. 1981zapper

    1981zapper Veteran Member

    I bought a rebuild '67 327 and it had the Original Harmonic Balancer on it (6.1"), it's in alright shape but i'm going to replace it, Which size of balancer should i put on it? the engine has not been balanced
     
    Last edited: Jul 27, 2010
  9. I run a 6+3/4" and thats what came on some 69 SS Camaros.
     

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