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Help Identifying a Cam

Discussion in 'Norton Commando Motorcycles (Classic)' started by marshg246, Nov 9, 2019.

  1. marshg246

    marshg246 VIP MEMBER

    Joined:
    Jul 12, 2015
    I have 72 bottom end that I'm rebuilding and it has a cam I can't identify. The only markings are in the picture and the lobe next to it has 3.3 (barely visible I the picture). If I'm measuring correctly, it has .370 lift for both intake and exhaust. Both ends are scrolled.

    Cam.jpg
     
  2. Matt Spencer

    Matt Spencer

    Joined:
    Jul 25, 2010
    Theres a possability it may be a 4 S , as it seems to be stamped ' 4 S '
    ' 6000 '

    THERE .
    Now a 4S is a 2 S with .020 of of the base . No doubt a shirt fight'll start.
    over that .

    Were early cams with a .020 greater base radius .

    When they started hitting the tappet guide block / Bottoming out , etc - with the High Lifts - past the 2S which was the olde factory RACE CAM ,
    In the first ' P R ' Knortons etc .
    They lost 20 thou off the heel , so they gcould grow a bit on the peak ( lobe )

    So there you are .

    Stamping can be a bit funny . A close look at the ' 3 S ' on removal ,
    was evidance it was really a ' S S ' but stamed on the circumferance a S appeared as a 3 unless you were out in the sun or used a eye glass .
     
    Last edited: Nov 9, 2019
  3. Dances with Shrapnel

    Dances with Shrapnel VIP MEMBER

    Joined:
    Jul 8, 2011
    Nose of the nearest lobe looks like it has spalled.
     
    SteveA likes this.
  4. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    I don't know who MS is but with 370 lift it is likely someones standard replacement.
     
    SteveA likes this.
  5. Time Warp

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

    Joined:
    Dec 3, 2012
    It also has a stamped T under the M like a stock cam.... Maybe it is a Delta regrind but the base circle would need to be measured.
     
  6. marshg246

    marshg246 VIP MEMBER

    Joined:
    Jul 12, 2015
    Base circle is .872

    Looking with a strong magnifying glass I can see that the MS and the 000 are clearly stamped. The 6 is not nearly as clear - its definitely a 6 but not as deep. The M may have been stamped over something else, but if so, it can't be made out.
     
  7. marshg246

    marshg246 VIP MEMBER

    Joined:
    Jul 12, 2015
    That one lobe does have a small imperfection that appears to be a manufacturing defect.
     
  8. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Whatever the cause of that imperfection, it’s on the nose, smack in the area of greatest stress and wear.
    That cam is therefore either scrap or a donor for hard welding IMHO...
     
    Dances with Shrapnel likes this.
  9. marshg246

    marshg246 VIP MEMBER

    Joined:
    Jul 12, 2015
    I agree.

    Part of what I'm trying to figure out is if it can be reground to standard or Combat or something else useful. I have no way to measure its timing. If someone can identify it, and then if I can find its parameters, I can decide.
     
  10. dynodave

    dynodave

    Joined:
    May 28, 2003
    You will probably not get a PW3 or combat out of a regrind.
    maybe one of these, closer to .350 lift:

    [​IMG]

    [​IMG]

    or:
    [​IMG]
     
  11. Dances with Shrapnel

    Dances with Shrapnel VIP MEMBER

    Joined:
    Jul 8, 2011
    I would think the price of sorting it out and regrinding to a useful profile is approaching if not exceeding the price of a replacement cam.
     
    SteveA likes this.
  12. Time Warp

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

    Joined:
    Dec 3, 2012
    That base circle diameter seems small so maybe a stock regrind... That sure does look like a factory stamped T with the M partially stamped over it and Delta Camshaft in WA sprang to mind.
    A moot point if the lobe is failing.
     
  13. Time Warp

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

    Joined:
    Dec 3, 2012
    If the base circle is already reduced so the lobe could be ground even on a stock profile I doubt it could be redone that way without build up of the marked section, but that area is not clear in the picture.

    It might be better to post a clear picture overhead of that marked lobe for someone like JC or DD to look at or it is just guess work or speculation.
     
  14. marshg246

    marshg246 VIP MEMBER

    Joined:
    Jul 12, 2015
    You are most likely right and I am already looking for a replacement.

    The only new ones available are expensive. I can get new Hepolite cams at a reasonable price, but they are chilled iron and I'm not sure I want that and I've not heard good or bad about them. The Hepolite billet cams are quite a bit more expensive. AN is out of stock and even more expensive still..

    This is another of my dumb ideas. I got a decent deal on this bottom end and planned to rebuild if for the next guy who came to me with a blown engine. Having to buy a cam makes that not so smart unless I can find a good used one. Fortunately the crank and rods are good.
     
  15. dynodave

    dynodave

    Joined:
    May 28, 2003
    My sample Web 132 BC is .877 I could live with a cam with only .005" smaller BC.
    What is a hepolite cam?

    OT: I have just recently measured a cam that has a 2S grind, but is absolutely a different scrolling which is of the MKIII oiler scrolling.
     
  16. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
  17. marshg246

    marshg246 VIP MEMBER

    Joined:
    Jul 12, 2015
    Hepolite is a company that has existed for a very long time, legally. They make pistons, rings, cams, etc. for Vintage British Motorcycles, some (all?) in the UK. They were bought by Wassell in 2011 if I remember right.
     
  18. Dances with Shrapnel

    Dances with Shrapnel VIP MEMBER

    Joined:
    Jul 8, 2011
    Good quality and selection with these folks:

    https://www.megacyclecams.com/

    comnoz on this list sells web cams which have a good reputation.

    jseng on this list sells his proprietary cams; they may be geared towards race tune but he can chime in here.

    There was a person in the Pacific Northwest (Johnson cams) who made a few grinds but I don’t know if he is in the fray.

    There should be an abundance of NOS OEM stuff and custom out there but buyer beware.
     
  19. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    'Hepolite' was a trademark used by Hepworth & Grandage which was a company that became part of AE, then much later Federal-Mogul.

    https://www.gracesguide.co.uk/Hepworth_and_Grandage
    "1947 Acquired by Associated Engineering Group."


    Wassell acquired the 'Hepolite' trademark so it's Hepolite in name only.

    https://www.totalbikebits.com/wassell_history.html
    "In 2011, the Company acquired the Hepolite brand, trademark and goodwill from the Federal-Mogul Group. Originally Hepolite was a brand name of Hepworth & Grandage, who later merged with Wellworthy Pistons Ltd, to form A E Piston Products Ltd"
     
  20. marshg246

    marshg246 VIP MEMBER

    Joined:
    Jul 12, 2015
    Ok, as usual, I stand corrected.

    Hepolite is a brand not a company. Since the 60s I've known them as piston makers and always thought the Hepolite was the name of the company.

    I suppose a great many companies and brands are in name only.
     

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