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231 OF cam specs

Discussion in 'Early CJ5 and CJ6 Tech' started by Rich M., Jan 26, 2016.

  1. Jan 26, 2016
    Rich M.

    Rich M. Shoe salesman 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Maryland
    Joined:
    Mar 23, 2008
    Messages:
    2,169
    Looking at replacing the cam in my 75 231 of. The factory specs are advertised duration 181/191 lift 257/254. I surmise the duration is measured @ .050 and lift at the lobe as the measurements seem low. If this is the case I really don't see the point in installing an aftermarket rv/ torque grind as the gains are minimal due to being advertised at seat to seat and valve lift to make the numbers look high. Any engine builder thoughts?
     
    Last edited: Jan 26, 2016
  2. Jan 26, 2016
    Deaner70

    Deaner70 Member

    Shreve, Ohio
    Joined:
    Jul 24, 2013
    Messages:
    73
    I have found that mine always likes lots of duration. I am at lunch and have cam card at home, but it makes a good bit of difference. The nicest one was are .468-.480 lift
     
  3. Jan 29, 2016
    maurywhurt

    maurywhurt Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Western North...
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    Dec 12, 2009
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    873
    Here's the cam card for the one in my odd-fire 225 (which is bored out to a 231). This cam, which is based on modified Comp 260H design specs, has a good deal of duration and lift, but with the 112 degree lobe separation, it idles very smoothly and doesn't "lope". You can see a video of the motor idling at this thread: 1967 CJ5 Dauntless V6 Engine Rebuild | EarlyCJ5.com As I noted in that post, with the new cam there is no noticeable change in low end torque, but mid and upper ranges have significantly increased power.

    My engine builder had built a number of 231's before he did my engine, and knew what he was doing when he spec'ed this cam, as it runs very well. Incidentally, the cam was nitrided (by Comp) to increase its durability.


    [​IMG]
     
    Last edited: Sep 12, 2017
  4. Jan 30, 2016
    Rich M.

    Rich M. Shoe salesman 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Maryland
    Joined:
    Mar 23, 2008
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    2,169
    IMG_20160130_241041_044.jpg Awesome thanks for sharing. I think my cam is a touch hot but I'm going to run it. One thing I dont know is what the lobe separation is. My card is almost 30yrs old!
     
    Last edited: Jan 30, 2016
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