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Another Norton headed for Bonneville this year

Discussion in 'Norton Commando Motorcycles (Classic)' started by jseng1, May 6, 2019.

  1. Snotzo

    Snotzo

    Joined:
    Mar 12, 2013
    Joachim, I would question the 85 crankshaft power, and must ask whether this was obtained via a direct crankshaft connection, or estimated/calculated from rolling road dyno figures.
    If the former, then the output is very credible, but if the latter I doubt there is anywhere near 85 at the crank
     
  2. cjandme

    cjandme

    Joined:
    Feb 5, 2011
    Ditto, great stuff and thanks for posting/sharing the details. This year is shaping up to be a good one for Norton land speed record attempts/efforts. This certainly has piqued my interest in the fun ya'll are gonna have Cj
     
  3. Joachim

    Joachim

    Joined:
    Jan 1, 2018
    Dear Snotzo,
    the bike was run on the dyno as you can see in the photos, i.e. engine to rear wheel losses estimated.
    Your concerns about the credibility of the power figure are more than fair. All I can say is that all the people involved are very experienced and they belief in the results. There was absolutely no need for anyone to make the results look any better than they are. So in my opinion these results are not less credible than any other results you see on forums like this. Probably no point getting scientific.
     
    Last edited: May 19, 2019
    KiwiNeill likes this.
  4. jseng1

    jseng1

    Joined:
    Nov 26, 2009
    When Ron Wood achieved 84 HP with his flat track 750 the people at the Norton factory (that was sponsoring him) didn't believe him either. They offered to fly him and his motor to the UK to prove it - and he did just that. I heard this from from Ron Wood personally when we were working on his Rotax single.
     
    Last edited: May 19, 2019
    KiwiNeill likes this.
  5. Dances with Shrapnel

    Dances with Shrapnel VIP MEMBER

    Joined:
    Jul 8, 2011
    Looks like the cylinder liners were notched to gain exhaust valve clearance. Good stuff!

    Ram air should be good for a few tenth of a psig at the carbs.

    https://i.stack.imgur.com/433lx.jpg

    Something to be cognizant of is the air box/air feed tubes/intake tracts acting as an Helmholtz resonator. Properly designed and tuned it can work for you, otherwise, it will work against you.
     
  6. Joachim

    Joachim

    Joined:
    Jan 1, 2018

    Thank you, will pass on your concerns.

    Isn't Ram Air where the air is directly forced into the intake of the carburettors? In this case the pipes go into the air box and the carbs get the air out of the air box. The experts apparently say that the pressure wont increase noticeable within the airbox.
     
  7. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Thanks for the details. Very interesting build.

    Ken
     
  8. grandpaul

    grandpaul VIP MEMBER

    Joined:
    Jan 15, 2008
    I would say some actual run testing of the airbox would be better done BEFORE the trip out to Bonneville! Just seems logical that you'd want to sort that out to the positive, before being disappointed and possibly limited resources to adjust, apart from rough modification or eliminating the ram air altogether...

    I know, it's hard to find a long strip, but you can always ask a private airport...
     
    Last edited: May 21, 2019
  9. Dances with Shrapnel

    Dances with Shrapnel VIP MEMBER

    Joined:
    Jul 8, 2011
    Ram air is not the issue or problem as long as the float bowls see the air box (dynamic “rammed” air) induced pressure. The resonance of the air box/intake tract/ducting (Helmholtz) system is the question. You can test that on a dyno independent of the ram air effect.
     
    Last edited: May 22, 2019
  10. Son of Siredward

    Son of Siredward

    Joined:
    Nov 4, 2012
    Tom Mellor runs a similar air induction system into a large air box on both his LSR bikes and has both the 750cc and 1000cc records in M-PG and MPS-PG BST AMA events. Claims to run sea level jetting at Bonneville with the air induction air box.
     
  11. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    I don't know how you guys can do that. I don't even like big road race circuits. At least with small circuits - if the crank lets go, you can get off relatively safely.
    Take care !
     
  12. jseng1

    jseng1

    Joined:
    Nov 26, 2009
    Here's the happy bunch of culprits with their project.

    [​IMG]

    Somehow this photo overwrote the original photo I posted at the top of this thread.
     
  13. Joachim

    Joachim

    Joined:
    Jan 1, 2018
    To everyone who doesn't believe in the 85HP, here you can hear every single horse :D

     
    gortnipper likes this.
  14. jseng1

    jseng1

    Joined:
    Nov 26, 2009
    85HP is an exceptional accomplishment for a 750. Very few tuners have managed that much power.
     

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