What's wrong with this picture? R50S

Discussion in 'Old's Cool' started by norton73, Jan 7, 2011.

  1. norton73

    norton73 drinkin'

    Joined:
    Dec 20, 2003
    Oddometer:
    8,350
    Location:
    Beautiful Downtown Springville, Alabama
    #1
  2. Sniper X

    Sniper X De Oppresso Liber

    Joined:
    Jul 18, 2006
    Oddometer:
    33,390
    Location:
    Central New Mexico, 7420ft above sea level
    Can you give me a hint or just outright tell me?
    #2
  3. bmwloco

    bmwloco Long timer

    Joined:
    May 13, 2008
    Oddometer:
    1,551
    Location:
    AsheVegas NC
    Looks like good clean track hooligan fun to me... just wear your leathers and a damn good helmet.
    #3
  4. norton73

    norton73 drinkin'

    Joined:
    Dec 20, 2003
    Oddometer:
    8,350
    Location:
    Beautiful Downtown Springville, Alabama
    Look at the heads :deal
    #4
  5. Sniper X

    Sniper X De Oppresso Liber

    Joined:
    Jul 18, 2006
    Oddometer:
    33,390
    Location:
    Central New Mexico, 7420ft above sea level
    Are they Krausers with stock covers or modified stockers?
    #5
  6. DaveBall

    DaveBall Long timer

    Joined:
    Sep 30, 2009
    Oddometer:
    1,163
    Location:
    Vancouver Island
    Nothing wrong with 4 valve heads. Might be Krauser or Luftmeister heads, or something totally different. Looks like a good design to me.
    #6
  7. Carl

    Carl ,,,

    Joined:
    Oct 5, 2001
    Oddometer:
    776
    Location:
    South Tejas
    Two words: all custom.

    Carl
    #7
  8. Uncle Ernie

    Uncle Ernie Long timer

    Joined:
    Jul 3, 2007
    Oddometer:
    3,978
    Location:
    Asheville NC
    Who said that's an "S"? Not anymore. Anyway- it's got the wrong rocker covers for an "S".
    Am I to believe he put a spark plug in the middle? Is that even possible?
    Why not just do a dual plug get-up? And if that IS an "S", it seems dumb to ruin a useless but never-the-less valuable lump when you could have found a normal 500 for cheap. I mean, the "S" was a little faster, but faster than what? A 12yo on a Schwinn Sting Ray?
    #8
  9. Tim McKittrick

    Tim McKittrick Long timer

    Joined:
    Dec 29, 2003
    Oddometer:
    1,793
    Location:
    Wasilla Alaska
    That's an amazing piece of work- custom heads, crank, rods, and pistons to make a higher revving motor with a modern 4-valve head design. Low domed pistons, narrow included valve angle, centralized plug.... I'd love to see a dyno chart on his final tuning results. This could be a 70 HP mill or better.
    #9
  10. Detroit Steve

    Detroit Steve Homely Adventurer

    Joined:
    Feb 6, 2008
    Oddometer:
    519
    Location:
    Further...
    It is a lovely machine with all kinds of fancy machining.


    I am wondering at the wisdom of the square slots ventilating the clutch area. This is not the first old BMW race bike where I have seen this, I just wonder why.
    #10
  11. Houseoffubar

    Houseoffubar fine beer sampler

    Joined:
    Dec 4, 2010
    Oddometer:
    1,824
    Location:
    Bothell, Washington
    How do you install the roller bearing crankshaft into the case with the rods already installed?
    #11
  12. Carl

    Carl ,,,

    Joined:
    Oct 5, 2001
    Oddometer:
    776
    Location:
    South Tejas
    No matter which HP rating you're using, an increase to 70HP is a stretch for that engine which is ~500cc and has just those mods. My comment here in no way pans the devotion they've placed in their design. The doubling of horsepower on 55-69 BMW twin engines is serious biz.

    Carl
    #12
  13. Lornce

    Lornce Lost In Place

    Joined:
    Aug 17, 2003
    Oddometer:
    18,344
    Location:
    Way Out There.
    Cool!
    #13
  14. RecycledRS

    RecycledRS Along for the ride

    Joined:
    Nov 2, 2008
    Oddometer:
    1,045
    Location:
    Vancouver Island
    Very nice work!
    Its called an R50S but the bore and stroke work out to 896cc. If true I think he may well get much more than 70 hp.
    #14
  15. Caddy82rats

    Caddy82rats Long timer

    Joined:
    Mar 8, 2007
    Oddometer:
    1,199
    Location:
    South France
    SUPERB work
    #15
  16. Carl

    Carl ,,,

    Joined:
    Oct 5, 2001
    Oddometer:
    776
    Location:
    South Tejas
    I must be missing where the bore and stroke increase on that engine is 896cc. From the pics it does not seem like the geometry and positional placement of the cylinder to engine case interface has been modified to have an increased bore to make it just south of a liter engine.

    The site has this: Bohrung 70mm Hub 64mm 500ccm. Visually the pistons look like a large bore and w/ a shorter stroke. So is it a 1/2 liter or 1 liter engine? Time for an e-mail to the builder.

    Carl
    #16
  17. RecycledRS

    RecycledRS Along for the ride

    Joined:
    Nov 2, 2008
    Oddometer:
    1,045
    Location:
    Vancouver Island
    Using the translator built in to Firefox, the first page of the site lists the bore as 64mm and stroke as 70mm (64*700= 448cc per side). Maybe something lost in the translation? Bill.
    #17
  18. bmwrench

    bmwrench Long timer

    Joined:
    Nov 10, 2006
    Oddometer:
    2,538
    That's how "/2" engines are assembled. The crank and rods go into the crankshaft tunnel, then the assembly gets rotated onto its back, then finally goes vertical to drop through the rear bearing counter bore. Just to add pleasure to the job, the case has to be hot enough for the rear bearing to drop in.
    #18
  19. Houseoffubar

    Houseoffubar fine beer sampler

    Joined:
    Dec 4, 2010
    Oddometer:
    1,824
    Location:
    Bothell, Washington
    Thanks Wrench! I could not see how they would fit. I've never seen a /2 motor up close, I will need to fix that!:lol3
    #19
  20. O.C.F.RIDER

    O.C.F.RIDER Loose nut behind h/bars

    Joined:
    Feb 28, 2004
    Oddometer:
    4,926
    Location:
    Hewitt,New Jerseystan, OBAMANATION
    I'll tell ya what's wrong with those pictures.............
    they weren't taken in MY garage! :lol3

    That thing is sweet.
    #20