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Cam and follower tests.

Discussion in 'Norton Commando Motorcycles (Classic)' started by comnoz, Aug 12, 2018.

  1. baz

    baz VIP MEMBER

    Joined:
    May 26, 2010
    whats the history of the modified norton follower in this picture? i have one single one in my collection and i wondered who did this mod?
     
  2. kommando

    kommando

    Joined:
    May 7, 2005
    Pity my OEM B40 cam follower lost its stellite pad then as otherwise it could be in my Norton, glad its not.
     
  3. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    Here are the followers from the Bonneville engine. Still have a little rust from the salt.
    It reved beyond 10,000 rpm with no problem....

    P1020532.JPG
     
    CanukNortonNut and worntorn like this.
  4. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008

    I am not real sure what the Webcams are finished to, but the followers were finish ground with a 400 grit CBN stone -so around 65Um I would guess.

    Lauri did say the cams finish would be suitable for a DLC coated follower, so that would indicate it was pretty fine.
     
  5. Brooking 850

    Brooking 850 VIP MEMBER

    Joined:
    Oct 3, 2011
    Jim, didnt you post a video on an oil additive showing its failure?
    Regards Mike
     
  6. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    That was STP's failure when used as prelube for a valve stem with minimal clearance.

    It would have had nothing to do with ZDDP or antiwear properties. Just the fact that it was too thick to provide lubrication in a tight new valve guide.

    ENGINE OIL ONLY FOR VALVE GUIDE PRE-LUBE. [At least for my head builds].
     
  7. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Instead of adding some kind of additive to the oil, why not just buy good oil with a high ZDDP content? That way you know the entire oil and additive ‘recipe’ is going to be good, and work together.

    I can’t follow the logic that says we blokes in our sheds can mix a better oil than the top end reputable oil companies !
     
    worntorn likes this.
  8. Onder

    Onder

    Joined:
    May 11, 2010
    The oil you use probably costs a good deal more than other oils plus the cost of the little bottle of zinc poop. For most of us oldsters the cost
    of oil today is unbelievable.
    However, the cost of our bikes is equally beyond what we would have ever paid so, as per your policy, false economy using less than premium oil.
    Maybe it doesnt matter, in which case you can simply say better safe than sorry.
     
  9. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
  10. Fullauto

    Fullauto VIP MEMBER

    Joined:
    Apr 13, 2009
    Since when have oil companies been reputable? You must have different standards to me.
     
  11. rvich

    rvich VIP MEMBER

    Joined:
    Jul 25, 2009
    Jim,
    How much mileage is on that cam?
     
  12. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    I don't know.
    If the owner see's this maybe he can fill us in.
     
  13. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    I think there needs to be a C.O.C. certificate added to the spiggoted lifters being sold lately. This is relevant in this discussion on the Norton type lifters. In comnoz's case as well as fullauto's who both do high mileage and use correct oil. One soft lifter takes out the cam. The $1000 question is why was there one, that was soft. Certificate of Conformance with RC values added. A German knife company Puma puts a Rockwell indent on all their knife blades to proof them. IMHO
    Cheers,
    Thomas
     
    Last edited: Aug 14, 2018
  14. Burgs

    Burgs VIP MEMBER

    Joined:
    Dec 14, 2013
    Hi Jim
    Very interesting subject you got going here, I am keen to see the results as I have had problems with Manx Cams and followers over the years with heavy wear.
    Had no problems with the original Norton cams but thought I would fit new ones and then the problems started, tried three different after market cams and follower sets.
    Now running a heavier oil with high Zinc load, and seem they seem to be holding up. After looking at your last post hardness could be one of the problems I am seeing.
    I did have them tested at one stage but I have lost the data, funny thing is everyone of the old guys I asked if they had any failures, said no.

    In your videos I note the wear patterns are not a full width it looks as if the cam is not ground square to follower but at full lift it appears ok?
    The Manx cams and followers have a full width witness marks straight from start up?

    Burgs
     
  15. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    Yeah,
    I'm not sure if the follower was off a little bit or if the wear pattern is due to cam flex.

    I have seen this before and since both followers were ground on the same fixture I suspect it's more due to cam flex. It always seems to be more evident on the RH followers.

    I didn't attempt to correct it as I wanted a bit of "worst case scenario" to see if the follower showed distress.

    In my new engine I have moved the cam bearings inboard -right to the edge of the lobes after eliminating the tach drive gear. I was hoping this might help make the contact more even.
     
  16. Burgs

    Burgs VIP MEMBER

    Joined:
    Dec 14, 2013
    Yes cam flex could certainly be a cause, making the moment arm shorter will help.
    I guess when you moved the bearing in on the timing side you kept the distance to the sprocket the same as original so as not to load up the drive end of the cam.

    Burgs
     
  17. oldmikew

    oldmikew

    Joined:
    Jul 25, 2015
    Thanks for posting the link . Used to be said that a rebuilt engine with a new cam and followers should never be allowed to idle as they need to 'work harden' . What might be the case is that the two surfaces are polished in the critcal first start up if the engine is not allowed to idle
     
  18. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    Yes, I put needle bearings right next to the lobes and a ball bearing next to the sprocket to support the RH end and control the end play.
     
  19. WZ507

    WZ507 VIP MEMBER

    Joined:
    Dec 26, 2013
    Per the table below, with your 400 grit CBN stone you should be right there in the same ballpark quoted in the Blair article for a CLA roughness of 0.25 micron give or take a bit.

    abrasive grit size vs surface finish.jpg
     
  20. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    "Yes, I put needle bearings right next to the lobes and a ball bearing next to the sprocket to support the RH end and control the end play."
    Jim, Your bike is highly modified (and I admire that) but what about us low life's who just rebuild to factory spec.
    What we need to see is a stock high mileage cam and lifter set up with Rockwell C testing on both Followers and Cam that have stood the test without wear. What can we derive from that correlation. I am really confused why one lobe takes a dump.
    Cheers,
    T
     
    KiwiNeill likes this.