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Cam and follower tests.

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

  1. Time Warp

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

    Joined:
    Dec 3, 2012
    Thanks for the reply I know you are busy in the 'Lab.

    Probably not that odd, but the lobes on my 850 measured and looked great, the followers had nice faces, smooth with no furrow at the centre/center like many yet the T/S cam bush was corrugated as was the cam journal and the follower sides showed some vertical pick up.
    I would have thought that was from lack of oil at some stage yet the lobes etc soldiered on without complaint.
    I believe them to be parts as fitted from when the bike was new, luck of the draw I guess.
     
  2. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Fascinating stuff, Jim. Please keep reporting. One of the takeaways I've got from this thread is how important oil choice is for our Nortons. I did not realize that Rotella had dropped the zinc additive from their formulation. Time for an oil change in my bikes.

    Ken
     
  3. Fullauto

    Fullauto VIP MEMBER

    Joined:
    Apr 13, 2009
    Funnily enough, Dave, they were. One warranty claim in 250 heads and the replacement head was on the way before the old one was off the bike. I even paid his mechanic's bill for him. Any other questions about my product? I somehow don't think there's a direct comparison in dealing with this issue, but, boys will play their silly games.
     
  4. Fullauto

    Fullauto VIP MEMBER

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    Apr 13, 2009
    Fair enough.
     
  5. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    I'm not so sure they have. This is the latest info I could find.

    http://pqiadata.org/Shell_Rotella_T4_15W40_4192017.html
     
  6. Jagbruno

    Jagbruno

    Joined:
    Jan 6, 2014
    A -perhaps- silly question from this non technical daily Norton rider from Belgium: since it seems that the abandon of zinc (and other metals) in the oil about 35 years ago is a crucial factor in these failures, are there commercially available products that could be added to the -otherwise fine modern engine oils we are all using- to prevent the issue on our street Nortons?
     
  7. madass140

    madass140 VIP MEMBER

    Joined:
    Nov 6, 2011
    STP Oil Treatment contains ZDDP. thats what I'm using
     
  8. Jagbruno

    Jagbruno

    Joined:
    Jan 6, 2014
    Thank you, Donald.

    Soooo, would systematically adding such an additive to our engine oil be a simple and adequate solution to the issue for street bikes, ...or not?
     
  9. madass140

    madass140 VIP MEMBER

    Joined:
    Nov 6, 2011
    I like to think so , I cant buy oil here with zinc so thats my solution. Others may have different opinions.
     
  10. Mr. Rick

    Mr. Rick VIP MEMBER

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    Feb 6, 2009
    I have come full circle, it seems. Back in the late 60's, you'd find Andy Granatelli on TV, telling everybody what a great thing STP was. So we believed him and Richard Petty, the racer, and used it.

    Fast forward to the late 70's: In 1978 STP Corporation and its then-parent company, First Brand Corporation, settled a legal action from the FTC over misrepresenting the role and benefits of motor oil additives in reducing wear inside engines. STP paid an $888,000 judgment, the third largest sum ever obtained by the FTC for a consumer protection violation.
    So we quit wasting our money.

    The stuff seems to be mainly a "Friction Index Modifier", which translates to "makes your oil thicker". If I were looking for more zinc, I'd look for something else.
    If I were driving an old worn-out smoker, STP might be a good idea.

    Sorry if this gets dangerously close to an oil discussion...
     
  11. concours

    concours VIP MEMBER

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    Dec 29, 2011
    oldbeezer and madass140 like this.
  12. Mr. Rick

    Mr. Rick VIP MEMBER

    Joined:
    Feb 6, 2009
    I just read a post where a fellow claimed that the hardness of the cam went way up (from about 30, to about 55) after break-in. Can this be true?
    If so, wd it be also true of the followers?
     
  13. MikeG

    MikeG

    Joined:
    May 31, 2012
    rel="lightbox">[​IMG]
     
  14. MikeG

    MikeG

    Joined:
    May 31, 2012
    I'd say that's a damn good average for any parts supplier, and excellent after the sale service too. Especially considering the nature and complexity of the product.
     
    madass140 likes this.
  15. o0norton0o

    o0norton0o

    Joined:
    Apr 27, 2015
    I use the valvoline VR1 synthetic in 20-50 wt. It has 1400 ppm of zinc and 1300 ppm of phosphorus. Of course I wonder if it helps slow down engine wear. spec sheet below

    https://sharena21.springcm.com/Publ...2d889bd3/8213a6c1-0cbd-e711-9c12-ac162d889bd1

    Having been a victim who survived a delaminated follower, because I heard the follower break off at an idle and then shut the engine off, I'm thinking of replacing all my followers with the spigotted type over this coming winter now that my paranoia has grown... I haven't heard back from my friend on whether his issue was also a delaminated follower, but if it was the cause then that just adds to my urgency to get rid of the old style followers still in my engine...
     
  16. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    It is not true of the case hardened cams or any of the hardweld cams that I have seen.
    Nor is it the case with Stellite [Delchrome] or hardweld followers.
     
  17. WZ507

    WZ507 VIP MEMBER

    Joined:
    Dec 26, 2013
    Since the conversation about cam/follower survival has drifted across the topic of oil-related factors and ZDDP, might as well bring surface finish into it too. The article linked below, by Prof G Blair & Associates, provides insight into 1) the importance of cam and follower surface finish, and 2) oil viscosity, and how oil film thickness varies as a function of camshaft angle, oil base weight, and oil temperature.

    http://www.profblairandassociates.com/pdfs/Camshaft RET 010.pdf

    Lots of things to think about as new data is generated and we continue the discussion. It would be interesting to know the range of surface finish that occurs across the myriad Norton cam offerings out there as well as the surface finish on the followers. Note that a typical ground surface finish of 0.25 micron CLA, as stated in the article, is 0.0000393”.
     
  18. rvich

    rvich VIP MEMBER

    Joined:
    Jul 25, 2009
    As for getting dangerously close to an oil thread, the discussion of oil fits with a discussion of cams and followers.

    I'd be curious to know, if you can't buy oil with ZDDP in places like Belgium or the Philippines, then what do people run in their diesel engines? Not their Volkswagen, but in heavy equipment or for marine applications? In North America, a trip to the marine supply will provide Chevron Delo 100 which isn't even sold for highway use but is about the only thing you can run in the 1-million still remaining in use two-cycle Detroit Diesel engines.

    I know I am naive, but has the rest of the world moved on to where a consumer can't get that stuff?
     
  19. jseng1

    jseng1

    Joined:
    Nov 26, 2009
    One problem with Norton lifters is their excessive mass.

    Every time the lifter is accelerated from a dead stop to full lift – the resistant forces of inertia put strain on the hard pad and try to wipe it off the lifter body. The heavier the lifter – the more the strain – and it adds up over time. Triumphs and BSA lifters don’t have as high a failure rate of lifter pads as Nortons do because they only weigh about ½ as much as Norton lifters and so the strain/wear is reduced. Norton could easily have incorporated a lighter lifter ... they didn’t. But some of the high RPM Norton flat track tuners switched to BSA lifters.

    Lightened BSA lifter below. BSA lifters were preferred over Triumphs because the BSA stems are stronger.

    [​IMG]

    Lightening a Norton lifter has been done but its difficult. Here is what I used to do to stock lifters to help drain the oil in and above the lifter to reduce weight. Credit to Mic Ofield
    [​IMG]
     
    Last edited: Aug 14, 2018
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  20. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    I wondered when the inevitable advertisement would get here....
     
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