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alternate rocker thrust washer

Discussion in 'Norton Commando Motorcycles (Classic)' started by fireflake, Jan 6, 2019.

  1. fireflake

    fireflake

    Joined:
    Apr 21, 2015
    Does anyone know if there are spacers available to replace the thrust/thackery washers for the rockers, thanks
     
  2. Rosey

    Rosey

    Joined:
    Aug 6, 2011
    I had some made for me using Aluminium Bronze but buying off the shelf today,not not that I know of.A very long ago Unity Equip in the UK used to sell them as set of four for Triumphs,not sure if the ID is the same as a Norton rocker shaft.
    You could have some made all a bit over size and grind them back to fit.No big deal.
    Where are you in OZ?
    Brett
     
  3. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Last edited: Jan 6, 2019
  4. fireflake

    fireflake

    Joined:
    Apr 21, 2015
    Thanks guys, looks like RGM is the way to go David
     
  5. Gilesy

    Gilesy VIP MEMBER

    Joined:
    Aug 27, 2017
    They look very neat, but just curious as to what advantage they give?
     
  6. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Less power lost to friction, and positive location of the rocker arm. Not sure how significant either of those advantages are. I've used the RGM kit, and it works well, but in most cases I just use the stock springs, and stack washers to center the tip of the rocker arm on the valve stem.

    Ken
     
  7. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    I’m Comnoz’ spintron thread he mentioned the benefits of having a ‘dampener’ in the valvetrain system.


    Does the spring perhaps provide some such dampening?
     
  8. Onder

    Onder

    Joined:
    May 11, 2010
    Ken, how much clearance did you give when you used washers no spring?
     
  9. Stephen Hill

    Stephen Hill

    Joined:
    Oct 28, 2009
    I am surprised the RGM spacers are made of brass. Though brass does come in varying hardness. If I were making them it would be out of bronze.

    Stephen Hill
     
  10. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    "Bronze" according to an old RGM paper catalogue.

    Also on RGM's old webshop page: http://www.rgmmotors.co.uk/main.htm >Catalogue>Top End [2/5]

    "56 050020 0.133" THICK BRONZE ROCKER SPINDLE THRUST SPACER"
     
    Last edited: Jan 8, 2019
  11. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
  12. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
  13. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    No idea, they could be bronze for all I know...
     
  14. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    They were listed by RGM for many years as "bronze".

    The Norvil thrust washers (and the ones sold by Mick Hemmings) are described as "bronze" so I think "brass" is probably an error.

    http://www.norvilmotorcycle.co.uk/
    "069506 WASHER - THRUST - ROCKER SPINDLE - BRONZE - FOUR REQUIRED - NORVIL"

    http://www.mickhemmings.co.uk/cat/PriceList.pdf
    "BRONZE ROCKER SPINDLE THRUST WASHERS (SET 4) ..............................TXK 026"
     
  15. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    No particular clearance spec. I bought packages of 3/4"x1/2" stainless steel shims in .015", .020", and .031" thicknesses, and just fitted them along with the bronze spacers and some original shims to get the rockers centered on the valve stem, with as little clearance as I could get with those shims and still have free rotation of the rocker.

    Ken
     
  16. KiwiNeill

    KiwiNeill

    Joined:
    Jul 25, 2011
    fireflake and onder

    Gidday mate, I,ve always used bronze spacers on the inner sides of the rockers and steel shims on the outers to centre the rockers with a clearance of around 0.005"

    Both types are from RGM and the bronze spacers set the alignment but have always needed customising to centre the rocker on the valve.
    I hand lap them to size on a small surface plate with 150-240 wet n dry checking thickness with a micrometer and doing each rocker individually until all are central.
    Steel shims are added on the outer side and clearance adjusted to the final 0.005" with the excellent AN allen key mushroom adjusters central on the Black Diamond valve stems.
    Before starting, smooth the rocker end faces and chamfer the edges to remove any sharp points left by the Thackereys, the depressions are OK, probably help lube.

    Easy and accurate valve clearance adjust and no problems to date with minimal wear on valve stems compared to the old style spring and standard adjuster setup I inherited with the bike.
    Another home brewed task needing patience and attention to detail but light on cost and high on job satisfaction when it,s done.
     
    Last edited: Jan 8, 2019
  17. Onder

    Onder

    Joined:
    May 11, 2010
    I did this a few years ago when I lived in the long cold New York State winters. As you say it takes time and attention to detail. But think it worth
    it for being able to centre the rocker on the valve alone.
     
  18. jseng1

    jseng1

    Joined:
    Nov 26, 2009
    ¾ OD Spring steel shims are available from McmasterCarr.

     
  19. ludwig

    ludwig

    Joined:
    Aug 30, 2006
    I use bronze spacers with zero clearance and a slight amount of friction .
    The expansion of the head will loosen them up .
     
  20. Klaus Monning

    Klaus Monning

    Joined:
    Nov 27, 2014
    Hello ,
    That's exactly the way to go. You may need to center the rocker to the top of the valve. It may add a bit of mechanical noise because of a bit of backlash to pthe rocker. I do the very same thing when I do my big valve conversions.
    The only question is: Does the rocker really need to touch the valve top in the center? If it touches it off center, the valve might rotate, which would be good for the wear of the sealing surfaces. But that 's theory.
    Best Regards
    Klaus
     

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