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New 750 Land Speed motor Herb Becker is building (with pics, for real this time)

Discussion in 'Norton Commando Motorcycles (Classic)' started by Eldo, Apr 5, 2019.

  1. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    Herb is building a new 750 motor to run at Bonneville Speedweek this summer. This 750 will have the same bore as our 920 engine (81mm), with a 73mm stroke. Here are some pics.

    [​IMG]

    [​IMG]
    Cylinders. Pistons from JS Motorsports, to Herb's design. Cylinders sleeved with LA Sleeve FL80 sleeves, bored to 81mm.

    [​IMG]
    One piece crank, 73mm stroke, machined manually by Herb Becker.

    [​IMG]
    Here you can see the ring lands have been moved down to accommodate the considerable valve pockets, shown below.

    [​IMG]
     
    Last edited: Apr 5, 2019
    Jerry Doe likes this.
  2. Hillbilly Bike

    Hillbilly Bike

    Joined:
    Oct 18, 2018
    What class will the bike be run in ?
     
  3. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    [​IMG]
    Herb has machined out the underside of the piston to save weight.

    [​IMG]
     
    NPeteN likes this.
  4. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    [​IMG]
    Sleeved Cylinders and BSA-style lifters.
     
  5. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    [​IMG]

    [​IMG]
    Lifters have been extended to maintain stability during high lift.
     
  6. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    [​IMG]
    Using Jim Schmidt's JS Motorsport 480 lift "Stage 4" cam

    [​IMG]
    44mm intake and 38mm exhaust valves.

    [​IMG]
    "Big block" Chevy pushrods.
     
  7. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    M-PG750/4 (Modified Production, Pushrod, gasoline, 750cc, 4 stroke)
     
  8. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    [​IMG]

    The head. Ported to 37mm. Intake face modified to accommodate larger intake tract.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  9. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    [​IMG]
    Steel plate to help re-inforce the cases on the "drive side".

    [​IMG]

    [​IMG]
    Cases bored to accept high lift cam

    [​IMG]
    The whole "Kit". Can't wait to hit the Dyno and see what it does!
     
    cjandme and NPeteN like this.
  10. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Beautiful stuff, especially that crank !

    Interesting that you’ve gone for the long rods even with that short stroke.

    Should rev like a 2 stroke on amphetamines !!

    What cam are you using?
     
  11. Hillbilly Bike

    Hillbilly Bike

    Joined:
    Oct 18, 2018
    SCTA Bonneville record for 750 MPG is decent 137 mph... 60 rear wheel HP should do it..
     
  12. grandpaul

    grandpaul VIP MEMBER

    Joined:
    Jan 15, 2008
    Wow. Nice stuff.
     
  13. grandpaul

    grandpaul VIP MEMBER

    Joined:
    Jan 15, 2008
    @ what total bike/rider weight?
     
  14. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    Jim Schmidt Stage 4, .480"
     
  15. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Very nice, as usual for Herb. Interestingly, we will be running an engine with similar design philosophy, but with 75 mm stroke and 79.5 mm bore, in the same class here on the West Coast. Actually, we plan to run both the gas and fuel classes at El Mirage, but probably only the fuel class at Bonneville. Should be a good year for landspeed Nortons.

    Ken
     
  16. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Might take a little more than 60. Back in 2001 the best we could do with 61 RWHP was 131 mph in perfect conditions at Bonneville. But Eldo's bike looks to have lower drag than ours, so 60 might be enough. In any case, I'm sure he'll have WAY more than that with this engine.

    Ken
     
  17. o0norton0o

    o0norton0o VIP MEMBER

    Joined:
    Apr 27, 2015
    Wow, Thanks for posting that. I'm feeling pretty ordinary now... :eek:
     
  18. Hillbilly Bike

    Hillbilly Bike

    Joined:
    Oct 18, 2018
    Hard to make comparisons, my 650 Triumph MPG bike has run 133 mph on 1-1/2 mile pavement in Maine at 1800 foot air density with 55 RWHP on a Superflow dyno...There's more drag with the salt but a bit less wind resistance.. And you need to make the 65 HP at Bonneville air density..But you know every bike and every run id
    sdifferent...
     
  19. Eldo

    Eldo

    Joined:
    Mar 19, 2015
    Yeah, we ran this set up in 920cc congiguration (95rwhp & without the front fender) at Loring and did a 146.7 in the 1 mile and 149.2 in 1.5 mile. We felt we were still accellerating. Did a 154.2 on the salt, at the 2 1/4 marker and at the 3 mile.
     
    Last edited: Apr 5, 2019
  20. Hillbilly Bike

    Hillbilly Bike

    Joined:
    Oct 18, 2018
    Interesting ,with less power at Bonneville than Maine you run faster on the salt despite the softer surface because of the longer distance I assume ?
     

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