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Commando Interstate

Discussion in 'Norton Commando Motorcycles (Classic)' started by PC49, Oct 2, 2018.

  1. PC49

    PC49

    Joined:
    Sep 25, 2018
    I recently purchased a 1972 matching numbers, disc braked Interstate. Have not previously owned a Norton.
    Were all of this model fitted with the Combat engine. Number 203xxx
     
  2. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    As far as we know, all '72 Interstates up to *211110* had the Combat engine.

    *(when production of the Combat engine is supposed to have ended)
     
    nortriubuell and PC49 like this.
  3. PC49

    PC49

    Joined:
    Sep 25, 2018
    Thank you for your response.
    I am very much looking forward to life with the Norton.
     
    Jag850 likes this.
  4. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Nice bike sir.

    Hope you don’t de-Combatise it!
     
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  5. PC49

    PC49

    Joined:
    Sep 25, 2018
    Absolutely not. It will remain a combat
    It has low miles but will look inside to check bearings and pistons and upgrade if necessary.
     
    kommando likes this.
  6. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
  7. PC49

    PC49

    Joined:
    Sep 25, 2018
    If they are still there (quite likely) we will replace. Thinking solid skirt. Do you have a recommendation.
     
  8. PC49

    PC49

    Joined:
    Sep 25, 2018
    I shoul have looked at the link first you have a recommendation. Thank you much appreciated.
     
  9. kommando

    kommando

    Joined:
    May 7, 2005
    Info is good but just be aware of Norvil's reputation or lack of one ;) when ordering parts.
     
    nortriubuell likes this.
  10. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Talk to Andover Norton, I believe they are now doing very nice pistons.
    Or... depending how much you wanna spend... check out JS Motorsports super light weight forged pistons and corresponding Carrillo rods...
     
    PC49 likes this.
  11. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    I posted the link as it has a good example of the slotted piston. Norvil wouldn't necessarily be my first choice of supplier though.
     
    nortriubuell likes this.
  12. PC49

    PC49

    Joined:
    Sep 25, 2018
    Appreciate all the advice as this is an area i have no knowledge in.
     
  13. PC49

    PC49

    Joined:
    Sep 25, 2018
    Do you see a need for Carillo rods for road riding.
    Raced cars and used to road ride an R1 hard and am mechanically aware.
    Combat will be cruising in the 70 to 90 mph range with occasional full accelleration use.
     
  14. bill

    bill

    Joined:
    Jun 1, 2003
    if you do split the engine cases do not get talked into butchering them as per old britts inoa tech digest oil pick up mod.
     
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  15. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    No there’s no ‘need’ for steel rods on a road bike. But the JS kit is a package, the longer rods seem to give certain benefits and the lighter pistons certainly do. I run them and think they’re fantastic. They’re not for everyone though. Check out his web site for details.
     
  16. PC49

    PC49

    Joined:
    Sep 25, 2018
    Yes they look excellent.
    I have used and benefited from longer rods in car racing.
     
  17. PC49

    PC49

    Joined:
    Sep 25, 2018
    Do you think it makes sense to go a bit taller from the Combat gearing maybe even std Commando.
     
  18. kommando

    kommando

    Joined:
    May 7, 2005
    You will lose on acceleration but gain more relaxed cruising, personal preference really.
     
  19. bill

    bill

    Joined:
    Jun 1, 2003
    if you plan to ride it at 70+ MPH for very long stints than you for sure will want to go to a larger countershaft sprocket. IMHO a 21 is the the best all round compromise for mixed riding but if mostly above 75 MPH than a 22 might better option. a 19 at 70 = 4500 RPM and a 21 at 70MPH = 4000 RPM these numbers are an approximation.

     
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  20. rvich

    rvich VIP MEMBER

    Joined:
    Jul 25, 2009
    Here we go...LOL. I have a Combat with a 19 tooth counter sprocket and I can't imagine cruising it between 70 and 90 MPH.

    How much stuff can one swap out and still call it a Combat?

    I'm considering a belt drive to improve the primary ratio, a different cam to give better mid-range torque, and I different head to improve the porting. Which sounds a lot like an 850. Anybody want to swap a Combat motor for a stock 850?
     

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