Down to 2 cams... Which one?

Discussion in 'Engine Topic' started by 71cmro, Feb 16, 2011.

  1. 71cmro

    71cmro Veteran Member

    1,392
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    Dec 3, 2003
    Beavercreek, OH USA
    Probably not much difference in them but I figured I would ask those that know. Thanks.

    Comp Cam 268h vs Comp Cam 270h

    Engine specs
    350 4 bolt main
    Eddy Vortec Intake
    Full length headers
    4bbl Quadrajet

    Heads
    Vortec cast iron 170cc Intake ports
    64cc combustion chambers
    1.940" Intake/1.5" Exhaust
    .475" max lift
     
  2. 5spd540

    5spd540 Veteran Member Lifetime Gold Member

    12,350
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    Sep 19, 2009
    Guyton, GA
    the270 sounds better but the 268 is mire street friendly
     
  3. 5spd540

    5spd540 Veteran Member Lifetime Gold Member

    12,350
    10
    Sep 19, 2009
    Guyton, GA
    What do you have for a converter
     
  4. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

    8,191
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    Jun 22, 2003
    Endicott, NY
    I am a die hard fan of the Qjet BUT it HATES big cams as it requires good vacuum at idle. So, I would choose the 268H because it is going to produce slightly more vacuum at idle.

    We've run that cam on a bunch of stock engines and quite honestly, I think it's about the best street cam you can use.

    Remember: less is more ESPECIALLY with cams. The BIGGEST mistakes are putting too big a cam and TOO big a carburetor. It's know as the BIBS: bigger is better syndrome. EX: if a 600 carburetor is good, then a 1150 HAS to be better. NOT!
     
  5. onovakind67

    onovakind67 Veteran Member

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    Jul 8, 2001
    Fairfield, CA
    What characteristics of a Q-jet require high vacuum at idle?
     
  6. Todd80Z28

    Todd80Z28 Moderator Staff Member Lifetime Gold Member

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    Jun 11, 2002
    Northern VA
    Both are single pattern, and IMO, both are wrong for the Vortec heads.
     
  7. mrvedit

    mrvedit Veteran Member

    1,346
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    Jun 12, 2009
    Ann Arbor, MI
    You might consider the XE268H which is dual pattern. However it has .520" of valve lift. I don't have experience with Vortec, but I understand it is easy to modify Vortec heads to support that much lift.

    Just checked - the 270H has .51" of lift, while the 268H has only .454 of lift.
     
    Last edited: Feb 16, 2011
  8. onovakind67

    onovakind67 Veteran Member

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    Jul 8, 2001
    Fairfield, CA
    The 270H has only .470" of valve lift with 1.5:1 rocker arms.

    http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=78&sb=2
     
  9. 71cmro

    71cmro Veteran Member

    1,392
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    Dec 3, 2003
    Beavercreek, OH USA
    Please explain. Many folks on here recommended these cams for vortecs last year when I bought them.
     
  10. 71cmro

    71cmro Veteran Member

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    Dec 3, 2003
    Beavercreek, OH USA
    Stock converter. From my research both will work with the stock converter but the 270 requires a 4bbl carb and headers which I have.
     

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