cam question

Discussion in 'High Performance Modifications' started by szaun b, Jun 11, 2017.

  1. szaun b

    szaun b New Member

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    Jun 11, 2017
    I am building a 350. i have it bored 30 over and had the crank balanced and have vortex heads. I am wondering what cam to run. I want a somewhat aggressive idle.
     
  2. Zspoiler

    Zspoiler Veteran Member

    2,319
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    May 6, 2012
    Federal Way, Washington
    All that depends on what you want to do with the car. If you are doing by yourself Check the local Speed Shops. Competent friends,and the Camshaft companies.Get the components that work together .
     

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  3. StrongSurvivor

    StrongSurvivor Member

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    Jun 5, 2017
    Bold Springs, GA.
    The Competition Cams Thumper series cams are known for that lopey idle so many desire. You haven't really said enough about the setup to offer any more than that. Comp Cams, Camquest application is pretty good for recommendations, providing you can input the required data. http://www.camquest.com/ If nothing else, the app will help you to understand just how much information is needed in order to make an informed camshaft purchase. One thing to remember and I've heard this my whole life. The biggest mistake people make when building an engine is TOO MUCH CAM!

    Good Luck!
     
  4. Zspoiler

    Zspoiler Veteran Member

    2,319
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    May 6, 2012
    Federal Way, Washington
    I have seen cars that are over camed and they are just "dogs" .All bark and no bite .
     
  5. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

    8,243
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    Jun 22, 2003
    Endicott, NY
    THEE most common mistake is TOO much cam!

    What carb is on your engine? If a Q-jet or Carter/Edelbrock or stock (non-racing) Holley, those carbs do not work well with "lumpy" cams because they are dependent of good vacuum at idle.

    Car has which transmission: automatic or manual? You might get away with a larger cam with a manual (inertia of the flywheel helps it run). Conversely, an automatic trans HATES a lumpy cam and you'll HATE how it runs.

    IMHO, get cam & lifters that works from idle to 5500 (maybe 6500) rpms. DEGREE THE CAM IN or you're wasting the power you should be gaining as you will NOT know where the cam is in relation to the rest of the engine.
     
    Mwilson likes this.
  6. Lou6t4gto

    Lou6t4gto Veteran Member

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    Aug 18, 2010
    Ocala, Fla
    WHAT Rear end gears ? what Transmission ? If Automatic, what torque converter ? intake manifold, carb, headers/exhaust ? Everything MUST be co ordinated with the other parts . I agree with "idle to 5500-6000 rpm" for the Street. Just throwing in ALOT (long duration) of cam just gets you a "No Go Show Boat". Then you need to TUNE the carb and ignition system. You pick a cam (Usually) for the RPM that you are usually driving in. generally about 2200-2600 RPM on the street.
     
  7. Chevyforever

    Chevyforever Member

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    Jan 4, 2011
    ontario
    Also the Vortec heads are limited to approx. .450 " lift if the springs / seals have not been changed. Guesstimate that you keep duration @ .050 less than 230* degrees. Like others have stated really need more info to accurately recommend a cam, intake,carb combo.
     
  8. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    Nov 4, 2004
    Ringgold, GA
    Just about all the major cam manufacturers will have some sort of online form to fill out, and they will give you a recommendation. Be prepared to answer a lot of questions.
     
  9. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

    14,377
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    Mar 25, 1999
    San Jose, CA, USA
    The cam is the single easiest way to ruin your engine. There is no "best" cam, there is just a cam that will match the rest of your combo.

    Info we'll need:

    1. Compression Ratio (probably around 9.7-1 but need real number)
    2. Intake Manifold you are using
    3. Carb you are using
    4. Exhaust size
    5. Are you running headers or factory exhaust manifold? If headers what size and style
    6. You mentioned Vortec heads, do these have screw in studs?
    7. What transmission are you running, if automatic what torque converter
    8. What is your rear end ratio (probably between 2.41 and 3.73)
    9. What is your intended use for this car (weekend-street, drag, autocross, daily driver)
    10. What is you budget for the cam and valvetrain?
    Any good engine guy will ask you all of these questions. If they don't before recommending a camshaft, than they don't know what they are talking about.
     
    2ndGenCrazy and Mwilson like this.

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