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Norris Cam and Regrind Questions

Discussion in 'Norton Commando Motorcycles (Classic)' started by swooshdave, Sep 10, 2019.

  1. gortnipper

    gortnipper VIP MEMBER

    Joined:
    Nov 11, 2013
    Well, that sluggishness has nothing to do with the 2s cam.
     
  2. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    And here are two Norton cams that give exactly the same motion at the valve.
    The left is made for 7/8th radius Triumph follower and the right is for a flat Norton follower.
    P1020983.JPG
     
  3. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    If you want to liven up the lower end when using a 2s cam on a low compression motor then re-mesh the cam gears to advance the cam 5 degrees. [or more]
    It helps get back some of that grunt you lost between 3 and 5000 rpm.
     
    Nater_Potater likes this.
  4. o0norton0o

    o0norton0o VIP MEMBER

    Joined:
    Apr 27, 2015
    Given that the 2 cams transmit the same motion to their valve train, does either cam/follower set up wear significantly better than the other? ... and if so why... (yeah, I got questions...)
     
  5. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    No, they seem to wear the same. This is a relatively mild street grind.

    If it was a big race cam like a Norris D grind or bigger then there may be a wear advantage due to the lighter Triumph follower.
     
  6. jseng1

    jseng1

    Joined:
    Nov 26, 2009
    Axtell#3 cams didn't have a lot of lift and they were available for flat lifters as well as radiused lifters. Some racers tried them both. A flat lifter Axtell cam looked beat up after a season. A radius lifter cam with the same valve action looked better with less wear. You had the choice of a pointy nose cam shape wearing on a flat surface lifter or a roundish nose cam wearing against a roundish lifter.
     
    Last edited: Sep 15, 2019
  7. Matchless

    Matchless

    Joined:
    Dec 23, 2010
    Jim ,
    Could the same thing work for a Maney cam which I believe is more or less the same as a 4S ?

    Martyn.
     
  8. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    Actually the Maney cam is a 2s combat cam. It will help to advance it with low compression.
     
  9. Matchless

    Matchless

    Joined:
    Dec 23, 2010
    Thanks Jim, I'll give it a go on my 750 which I have always found a bit lacking at lower revs. Steve insisted that there was no need to alter it from the standard setting. The engine has a stage 1 head job & the CR is 8.7 : 1 if I remember correctly.
     
  10. Ron L

    Ron L VIP MEMBER

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    Feb 27, 2004
    Agreed. More a function of the 22 tooth gear vs. the 19 tooth.
     
  11. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    So 9 links instead of 10?
     
  12. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    No, you would go 11 links and then go forward 3 teeth between the crank and intermediate.
    1 chain tooth is 15 degrees and three gear teeth is 17.5 degrees. So that gives you 2.5 cam degrees or 5 crank degrees of advance.
     
    swooshdave likes this.

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