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Long lasting hard welded cams

Discussion in 'Norton Commando Motorcycles (Classic)' started by jseng1, May 19, 2018.

  1. jseng1

    jseng1

    Joined:
    Nov 26, 2009
    Here's a cam core with the lobes ground down and re-welded with hard weld (Hero 56 or 60 weld rod).

    [​IMG]


    Here's a hardwelded cam after regrinding and finishing.

    [​IMG]

    The other long lasting options (if you can get them) are steel billet with plasma nitriding or billet made from S7 tool steel. S7 is the new kid on the block.
     
    Last edited: May 20, 2018
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  2. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    Which of your cams gives the best boost to power from 3000 RPM to 7000 RPM ?
     
  3. Brooking 850

    Brooking 850 VIP MEMBER

    Joined:
    Oct 3, 2011
    Al, that would depend on what other hardware you are running to support any cam?
    I use Jims JS2 in my race bike which gives great midrange results, although lots of other hardware supports that.
    Regards Mike
     
  4. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    When you only change the cam in a motor, the result you get is often a displacement upwards of the power band. With a normal Commando engine, revs will kill it. So improving the original power - band is the way to go. A race cam usually gives more power everywhere, but moves the usable rev range upwards to give more top end. More firings per minute gives more power. A good cam for a Commando would be one which has a lift-rate and closing rate and a lift which fattens the midrange, rather than one which changes the timings to move the power-band upwards. However that said, the exhaust system configuration has an effect on what shape cam and what timings are needed to give the best midrange power.
    Are you using a 2 into 1 pipe with the JS2 cam ? I'd be interested to know how much dyno work has been done in shifting the cam timings to suit various exhaust systems. If you compare what you do with a big four stroke, with playing with a two stroke - it is the same game. Kadency effects still play their part, and changing valve timings is the same as cutting up transfer and exhaust ports to shift the power band or get more torque.
     
  5. mdt-son

    mdt-son

    Joined:
    Jan 19, 2012
    Jim, what about the economics? What is the cost ratio of a camshaft with re-made lobes vs. a steel billet nitrided camshaft vs. an S7 billet cam?

    Another question: You supply hardwelded cams as well as steel billet and nitrided camshafts. Do you provide a service for user-supplied cores?
    I have one of the soft Mk3 cams on the shelf which I'd like to have refurbished.

    -Knut
     
  6. jseng1

    jseng1

    Joined:
    Nov 26, 2009
    The hardwelded and steel billet cam cost about the same. I've also been selling the EN40B plasma nitrided billet cams and they have been holding up well. To refurbish your worn cam it needs to be hard welded and reground. I can radius your stock lifters and this combo will far outlast the original stock setup. You have the choice of 4 cam grinds from stock performance JS0 to the radical JS3 (D+). I only sell cams that are designed for the longer lasting radiused lifters (not cams designed for flat lifters with radiused lifters substituted).

    S7 tool steel is what the some of the Nascar & drag racing people are going to and they have moved away from hardwelded lobes. But S7 has never been tested on a british bike to my knowledge. It needs a trial and if it works it will be the next hot item. I am presently working with a cam designer/manufacturer who in pushing me to use the S7. Its just a question of time $ and testing. But the end user cost of the S7 billet steel cam should be about the same as the others mentioned above.
     
  7. mdt-son

    mdt-son

    Joined:
    Jan 19, 2012
    Thanks Jim.

    -Knut
     
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