Basic cam/lifter question...

Discussion in 'Technical' started by scooper77515, Nov 20, 2006.

  1. scooper77515

    scooper77515 No current projects.

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    If my cam says it has .500 lift, and I use a 1.6 rocker, does that give me a total of .8 lift on my valve...?

    Seems like it should work that way...

    If so, when a valve is supposed to max out at .500, should I buy a cam that, with my lifters, gets as close to, but not exceeds .500?
     
  2. NAFORD302

    NAFORD302 Member

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  3. ShadowMaster

    ShadowMaster The Bad Guy

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    Huh? :slap:

    Typically, you'll find most lift numbers relating to valve lift. IE: .500" lift is the distance the valve moves off the seat. You need to see the LOBE lift and multiply that number by the rocker ratio to get your theoretical valve lift. In your example, the .500" lift would be divided by the rocker ratio to get a .3125" lobe lift.
     
  4. maverick1970

    maverick1970 MCG State Rep

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    It should specify on the Cam spec card. The card should specify lift at the cam and lift at the valve with a specific ratio rocker. With a few exceptions, most stock small block Fords utilize a 1.6 rocker. So if you have .500 lift at the valve you will have .3125 at the cam. With this in mind if you swapped to a 1.7 ratio rocker you would receive .53125 lift at the valve.
     
    Last edited: Nov 20, 2006
  5. ShadowMaster

    ShadowMaster The Bad Guy

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    Or a .53125" lift. If he gets a 5" lift cam out of a rocker swap.................. :D
     
  6. Rick Book

    Rick Book Member

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    Huh? :slap:
     
  7. ShadowMaster

    ShadowMaster The Bad Guy

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    Look........
    See.........joke.
     
  8. Grabber5.0

    Grabber5.0 Gear-head wannabe

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  9. NAFORD302

    NAFORD302 Member

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  10. maverick1970

    maverick1970 MCG State Rep

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    Ooopps, thanks for the correction:slap: Guess that would the valve into the crank!:rofl:
     
  11. scooper77515

    scooper77515 No current projects.

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    I am only a little bit lost...

    Let's use an example I have been looking at.

    My heads GT40Ps are supposed to be good for .500 lift.

    My rockers are 1.6, and I am looking at a cam, with, let's say .500 lift exhaust (so I can better utilize my heads).

    What is REALLY going to go on with my valves in this case?

    I admit, I might be misunderstanding some of the terms, so feel free to correct me if needed.
     
  12. maverick5.0

    maverick5.0 Member

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    check the hood clearance with the 5" valve lift( super tall valve covers )
     
  13. maverick5.0

    maverick5.0 Member

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    check for coil bind at maximun lift, especially the exuast valve must have at least .060" clearance or more.
     
  14. ShadowMaster

    ShadowMaster The Bad Guy

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    That is .500" lift AT THE VALVE.
     
  15. maverick1970

    maverick1970 MCG State Rep

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    What cam do you have?



     

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