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camshaft lobe gone

Discussion in 'Norton Commando Motorcycles (Classic)' started by Drummer99, Mar 30, 2019.

  1. Drummer99

    Drummer99

    Joined:
    Oct 18, 2013
    Hi folks thanks for all the feedback on my camshaft key As I inspected the camshaft further I discovered that the lobe second from the drive side basically was gone ! There was a thin piece of metal left but the lobe was worn flat? So after discovering this I ground the key off and removed the camshaft. I further dismantled the engine Con rods look new and crank journals are dead on original . I was expecting the worst Crank looks like it was disassembled as the flat plates were not bent back over and nuts are not pinged. Has anyone ever seen a camshaft worn like this? I can see no signs of a problem Thanks Drummer99
     
  2. Onder

    Onder

    Joined:
    May 11, 2010
    Worn cam on a Norton? er.....take a look at older posts.
     
  3. Lineslinger

    Lineslinger VIP MEMBER

    Joined:
    Feb 26, 2017
    You have a photo?
     
  4. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    Your Norton is probably one of the models intended for use in America, where they drive on the other side of the road.
     
  5. Time Warp

    Time Warp .......back to the 70's. VIP MEMBER

    Joined:
    Dec 3, 2012
    I found the same thing, it turns out they are only there to stop the steel alignment pin from going anywhere (cheek/flywheel/cheek)

    Have I seen that wear personally, no and I don't want to. :D
     
  6. ashman

    ashman

    Joined:
    Jul 11, 2010
    I have heard about some Mllls having soft cams installed, but if the cam hasn't been heat treated properly the same thing can happen but its strange only one lobe to suffer this problem.
    I have a few old Commando cams in my collection with a little wear markes on the lobes or a few chips but none with completely worn lobes, sound like the heat treatment failed when made or not done right, might have been made on a Monday when someone had a big weekend, who knows what had happened.

    Ashley
     
  7. Time Warp

    Time Warp .......back to the 70's. VIP MEMBER

    Joined:
    Dec 3, 2012
    I wonder if you can get a good (used) camshaft (Re ? >) nitrided or some other hardening ?

    Ashley, I have a 1970's Moto Guzzi also, wear on the left cylinder exhaust lobe Only is not unusual... hardness, lack of oil splash who knows... If a cam is nitrided how can one lobe resist the process (unless the steel was different on that lobe)
     
    Last edited: Mar 30, 2019
  8. ashman

    ashman

    Joined:
    Jul 11, 2010
    When I first converted my 850 into the Featherbed I got my stock cam built up to Combat specs 2S cam and cam grind from well known cam manufacture Ivan Tighe here in Brisbane and this cam is still as good as the day I built the Featherbed in the early 80s and years later working at Tec College (TAFE College) I drove the Auto students for two tours through Ivan Tighe workshops and all the workings of making and building up hot cams and the whole process of heat treatment, his son has taken over and has downsided the business and has lost his dads good reputation as a great cam builder.
    So yes can get the cams rebuilt and regrind to standard grinds but its about the same price of buying a new cam, whether the new cams are the same as the orginals who knows.

    Ashley
     
  9. Nortoniggy

    Nortoniggy

    Joined:
    Nov 17, 2010
    My Commando has just had its third camshaft in its life. Both ones that failed were original 70's cams. I've now fitted a new Andover cam and new followers. For years I used Silkolene straight 40 oil but for the last few years used Valvoline 20/50. I have no idea if the Valvoline had a bearing on the cam failure but won't use it again. I'm trying the Bel Ray as recommended by Jim. It seems to have got black pretty quickly though, so I'm seriously thinking of going back to the straight 40.

    Ian
     
  10. Onder

    Onder

    Joined:
    May 11, 2010
    How quickly is quickly? I used to change every thousand miles back when I lived in the states and oil was cheap. Not so here sadly.
     
  11. acadian

    acadian VIP MEMBER

    Joined:
    Mar 5, 2010
    Try the Castrol Classic 20/50, scored well on Jim's test and made for flat tappet engines
     
  12. Drummer99

    Drummer99

    Joined:
    Oct 18, 2013
    I picked up a good used camshaft from a friend I am going to have it polished up. Where do you get a cam Nitrated? The odd thing about this motor now that I have really had a good look at it. The crank journals are perfect the con rods look new and there is no wear on the shells Where did all the metal go from the cam ? Nothing in the crankcases Almost looks like someone half rebuilt the engine Thanks for all your input Drummer99
     
  13. jbruney

    jbruney

    Joined:
    Jan 5, 2019
    Black Magic. It came to this continent along with Europeans centuries ago.
    HA rebuild and quickly sold off. I believe you've figured correctly. A dastardly deed.
     
  14. kommando

    kommando

    Joined:
    May 7, 2005
    Ring up local metal heat treat outfits, if they don't do it ring up some local toolmakers and ask them where they get it done.

    If the engine is not half built then the oil filter will have caught it, if no filter then it may be as sludge in the bottom of the oil tank.
     
  15. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 25, 2004
    heres a worn cam for yas

    DSC09564 worn.jpg
     
  16. jbruney

    jbruney

    Joined:
    Jan 5, 2019
    Cupped..What's follower look like? Just curious.
     
  17. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 25, 2004

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