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Heart Transplant

Discussion in 'Norton Commando Motorcycles (Classic)' started by swooshdave, Aug 17, 2018.

  1. motorson

    motorson VIP MEMBER

    Joined:
    Nov 29, 2011
    But, Swoosh, by doing the best job you will be releasing another great Commando engine to the world! That in itself is a worthy cause. You definitely have a combat crank case with the oil intake way at the front. The modification on that is an important one if an engine is to be run hard. (What Norton does not get run hard from time to time?) I would build it as well as I could reasonably afford even if it was just to keep it as a spare engine. (too bad about your agreement with the original owner.) In my view, every once in a while an entire Commando will fall out of my extra parts. :)
     
  2. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    I agree with Fast Eddie,
    Don't cheap out. New crank bolts, Superblends and new shells after checking the crank journals if they look good. Most of these engines of that 200000 series were not using oil filters back then and I think it was introduced around 1973 onward as standard. (but don't quote me on this) If you are going to do this all over again, then a 17mm drill rod 1 ft. long and two hard wood pcs from the hardware store is all I use.
    I would do the dynodave oil pickup mod on the cases while your in there and you should have a good strong engine. What cam do you have in there?
    Keep on keep'n on.
    Cheers,
    Thomas
     
  3. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009

    I don’t think the cases in 1972 were any different at all between the Combat and non-Combat. It was the cam and shaved head and bigger carbs but that was about it.

    Am I wrong?
     
    kommando likes this.
  4. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    Shorter pushrods, bigger ports on the head. But that doesn't necessarily mean that was a good thing. I think Dynodave tested his combat on a dyno which put out 48 hp at the rear wheel with the smaller ports. Any markings on your cam?
    Cheers,
    Thomas
     
  5. kommando

    kommando

    Joined:
    May 7, 2005
    Cases for 72 were common to Combat and non Combat. Best to call them 72 cases not Combat cases.
     
    swooshdave likes this.
  6. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
  7. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    [​IMG]

    Say... what's this?

    [​IMG]

    So this engine never was upgraded to Superblends. So I can either downgrade the cam or upgrade the bearings or just stay off the top of the rev range...
     
    Last edited: Dec 22, 2018
  8. Hortons Norton

    Hortons Norton

    Joined:
    Oct 12, 2007
    Looks like one to me.
     
  9. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    Standard pre-'Superblend' MRJA30 roller(s) as there's no visible etched '6' which would identify it as a 'Superblend' (6/MRJA30).
     
  10. Hortons Norton

    Hortons Norton

    Joined:
    Oct 12, 2007
    What would be the difference?
     
  11. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    6/MRJA30 is the 'Superblend' bearing.
    MRJA30 isn't.

    https://www.nortonownersclub.org/su...mando/commando-main-bearings-service-releases

    "We are introducing a new roller main bearing arrangement in production almost immediately. The fitting of this bearing arrangement reduces overall width between the main bearings and increases timing side main bearing journal diameter.

    For service purposes we shall in future supply only the crankshaft of the latest size, Part No. 063106. The main bearings, Part No. 063114, must be used in conjunction. The new bearings are 2 dot single lip roller bearings and should be assembled with the lip into the crankcase in both cases.
    Main bearing Part No. 063114 is of the Ransomes type (R&M) MRJ A30.

    October 1971"
    __________________________________



    "In order to extend main bearing life, a change of roller main bearing specification has now been authorized and fitted on production engines from Engine No. 211891. The new roller bearing is designated 'Superblend' with an increased load carrying capacity and is supplied under Part No. 063906 (manufacturers part number R&M 6/MRJA30).

    August 1972"
    _________________________________

    "Only use bearings with one of the following numbers:- NJ306E (E is very important, NJ306 is weaker) or 6 MRJA30. The 6 may be hand engraved on the bearing."

     
  12. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    I believe you are correct.
     
  13. Hortons Norton

    Hortons Norton

    Joined:
    Oct 12, 2007
    Thanks L.A.B. I never knew that there was a change of size, I am in the process of building an Atlas and already have the bearing, better check. Chuck.
     
  14. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    sd quote "So this engine never was upgraded to Superblends. So I can either downgrade the cam or upgrade the bearings or just stay off the top of the rev range..."
    swooshdave, give us a picture of the head showing the gasket surface area. I want to see it there is any material skimmed off the head aka "combat-ted".

    Superblends would be the cheaper option $74.80 each via Old Brits. a new cam will be much more. Is all the lobes as good as the picture shows? Based on the head if it is not skimmed, You could up the compression to close to combat by eliminating the base gasket (use 518 loctite) and using a thin head gasket system. I didn't see a C stamp on the head.
    This will make the cam which you have work, as this cam needs compression. Only check the valve coil bind when assembly. That engine should pull like a train and give you lots of power and grins.
    Cheers,
    Thomas
     
    Last edited: Dec 22, 2018
    Fast Eddie likes this.
  15. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
  16. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    [QUOTE="swooshdave,


    Only managed to break TWO of @Mike T's tools... :eek:


    [​IMG]

    The second tool to fail was the pinion puller. Fortunately it still did the job with only two arms. Does anyone have a spare one laying around they want to sell? :oops:



    The good news is that it should be ready to split, what else could possibly go wrong??? o_O[/QUOTE]



    I could only imagine the words out of your mouth when that happened!:mad:
    It is too bad that we can't buy just more jaws for the puller. I think we need to talk to AN about that.
    bummer just the same.:oops: You really need to make the outer ring nut as snug as can be with no misalignment behind the gear.
     
    Last edited: Dec 22, 2018
  17. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    Luckily @Mike T was actually helping me at the time so we could share the profanity.

    There are many brands of pullers out there. And since they are shared with Triumphs they are readily available and not horribly expensive.
     
    Last edited: Dec 22, 2018
  18. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    [​IMG]

    As for the connecting rod holder I got some red oak and will cut the appropriate holes in it. Provided I run the grain the right way it's shouldn't ever break.
     
  19. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    I want a picture of your head. we can work on red oak later.
     
  20. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    :oops:

    Yeah, waiting for the youngest to go to bed. You'll need to wait for him too.
     

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