Worn PW3 cam

Discussion in 'Norton Commando Classic Motorcycles' started by Fullauto, Apr 20, 2018.

  1. Fullauto

    Fullauto VIP MEMBER

    Joined:
    Apr 13, 2009
    Anybody know of any worn out PW3 cams? 26,000 miles, Lifters perfect. Jim Comstock's conical valve springs.
     
  2. Mike B

    Mike B

    Joined:
    Oct 16, 2015
    After 4000 miles, showing noticeable wear. I believe they tend to be a bit soft.
    Mike B
     
  3. dobba99

    dobba99

    Joined:
    Jan 25, 2014
    Yes, 1200 miles and two lobes badly worn. Went back to using the standard profile. PW3 Performance wise, no real benefit (3 hp from the bottom end to put 2-3 hp at the top end) apart from a bit more of a 'crack' to the exhaust.
     
  4. oldmikew

    oldmikew

    Joined:
    Jul 25, 2015
    This is bad news .. any of you take the matter up with suppliers ? Soft cams on the 850s where an issue in the 70s, but I understood PW3 was usually chilled cast not of itself a guarrantee against letting new cams run in motors that are idling, but better than the 4S steel cam I have whose lobes can be scratched with a hacksaw. Probably not En40 so should not have been subject to nitriding
     
  5. toppy

    toppy

    Joined:
    Dec 2, 2012
    Where did you get it from ? Mine is a chilled iron one from Mick Hemmings with his serial number on it. I got it an its lifters secondhand an so have no idea of the mileage but it must be more than yours an it was fine the last time i checked. I just changed the oil an there was next to no metallic particles on the three magnetic drain plugs either.
    Cams in general seem to be a never ending issue like wet sumping an many other things but if the start loose the harden outer surface things go bad very quickly.
    Is yours just one lobe or more that is affected?
     
  6. yves norton seeley

    yves norton seeley

    Joined:
    Feb 13, 2014
    Before I was using JS cams, I was using a PW3, never a problem with it till the day, at a drag race, the PW3 broke in two pieces
    Yves
     
  7. Fullauto

    Fullauto VIP MEMBER

    Joined:
    Apr 13, 2009
    Off the shelf at Andover Norton/ I shall be taking this up with them. This is very poor indeed.
     
  8. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    What oil are you guys running? Could this be some hint to any wear issues.
    Curious. o_O
    Thomas
     
  9. comnoz

    comnoz VIP MEMBER

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    Dec 10, 2008
    Got two shot PW3's on the shelf. Definitely wasn't oil. Jim
     
  10. ntst8

    ntst8 VIP MEMBER

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    Feb 14, 2004
    Sounds a bit scary, i fitted one a year or two back so following with interest.
    There was an article i think in Roadholder a while back which from memory suggested the Norman White and others all went to the same supplier for PW3's.
     
  11. worntorn

    worntorn

    Joined:
    Dec 22, 2006
    The crappy thing with a cam grinding down quick like that is the amount of relatively hard grindings it puts thru everything else.

    Glen
     
    oldmikew likes this.
  12. oldmikew

    oldmikew

    Joined:
    Jul 25, 2015
    There was a piece in Roadholder about precisely this mishap but it did not involve a pw3 .. Les Amery cast doubts on the suitabilty of cast iron as camshaft material.. saying all his are made from EN40.
     
  13. kommando

    kommando

    Joined:
    May 7, 2005
    All the chilled cast cams will have come from 1 source.

    http://www.newman-cams.com

    So it's either a batch issue or chilled cast iron is not suitable for the application.
     
  14. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Sadly Ken, you are not alone with this problem. Lots of theories and counter theories out there, good luck navigating your way through that lot!

    I prefer hardened steel cams over chilled cast iron, simply because I’ve had lots, mainly in Triumphs, and they do tend to last well... but they’re only as good as the hardening process.

    But my real preference is for hard welded steel cams, ala JS or Comnoz Web cam.
     
  15. Fullauto

    Fullauto VIP MEMBER

    Joined:
    Apr 13, 2009
    Furore on Facebook. Local man in the same boat with his engine built at the same time as mine. Same problem. I think this is shaping up to be a batch issue. Both cams were sourced from the same supplier, about the same time, but there's plenty of reports of PW3 cams lasting forever. My cam is being metalurgically tested so I will await the results.
     
  16. oldmikew

    oldmikew

    Joined:
    Jul 25, 2015
    Newmans no longer list PW3
     
  17. Fast Eddie

    Fast Eddie VIP MEMBER

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    Oct 4, 2013
    Because only Hemmings (now AN) and Norman White are official retailers as I understand it. Newman’s make them though.
     
  18. Fullauto

    Fullauto VIP MEMBER

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    Apr 13, 2009
    Well, let's see who stands by their product then, shall we?
     
  19. Fast Eddie

    Fast Eddie VIP MEMBER

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    Oct 4, 2013
    Theres plenty of reports of premature wear too! And from way outside of your batch Ken.

    Why not do a poll on here? Who’s had one last forever, who’s had one fail prematurely.
     
  20. oldmikew

    oldmikew

    Joined:
    Jul 25, 2015
    Newmans did offer PW3 in EN40 B as well , anyone sourced this from them direct
     

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