R60 versus R75 help

Discussion in 'Airheads' started by China2wheels, Jan 12, 2013.

  1. China2wheels

    China2wheels Been here awhile

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    Hi

    I need some help distinguishing between an R60 and an R75 engine.

    I bought a sidecar bike with a refurbished BMW engine in it, supposedly with a 750cc engine (well, that is what I paid for). The builder claimed it is an R75 (750 cc) but he put an R60 badge on it because he had "run out" of R75 badges. The builder puts various sizes of BMW engines in CJ750 sidecars.

    Is it possible that this is an R75 but badged with an R60 plate?

    Is there a difference in the outward appearance of these two different engines? Is it possible to mount an R60 badge on an R75 engine (e.g., are there any holes that are supposed to line up, etc?)

    Here are a few pics of the left side (sorry, I don't have any right side pics of the engine)

    [​IMG]

    [​IMG]

    [​IMG]

    Thanks for any help you can provide.
    #1
  2. Big Bamboo

    Big Bamboo Aircooled & Sunbaked

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    What is the serial number on the case by the dip stick? Number plates are attached to the starter cover with glue. Lots of modifications to that engine, who knows ?
    #2
  3. subagon

    subagon Hopelessly lost

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    The serial number on the engine is no guarantee. Just from the picture this engine been modified (valve covers, carbs, etc). It could also have jugs and pistons different from what the serial number would imply. The serial number will tell you what the engine was when it left the factory. Pulling the head and measuring the bore will solve the mystery. Maybe a guru will have a simpler way to ID the engine size. I think there should be some mark or number at the base of the cylinder that would ID it.

    Edit: I took a look at my R60/5 and R75/5 and the jugs are slightly visually different. However, I'd pass this off as differences between year models and not engine size.
    #3
  4. Mark Manley

    Mark Manley Been here awhile

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    On the later nikasil barrels the size, 80 or 100 is cast into them with raised letters at the base giving the capacity, I am not sure if the /7 have this but take a look, if it says 60 it's a 600, 75 it's a 750. Apart from that and the badge they are identical to look at.
    #4
  5. China2wheels

    China2wheels Been here awhile

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    Thanks guys - appreciate the help!
    #5
  6. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    Holy moley. It's the Ultimate Frankenbeemer engine. And I'm not even sure it's a BMW engine. Ural engine? Chinese Ural clone? 600cc or 750 cc is the least of your problems...

    Run. Run away!
    [​IMG]

    --Bill
    #6
  7. captainjohn

    captainjohn Adventurer

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    My thoughts exactly, That is not a BMW engine
    #7
  8. disston

    disston ShadeTreeExpert

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    The transmission is definitely not BMW and the engine may not be. The timing plug looks right but there is what appears to be an extra hole in the block in the last photo below the inline fuel filter. Also the engine front cover and the timing chest cover don't look right. Need more pictures.

    Plastic name tags can be put on anything.
    #8
  9. chasbmw

    chasbmw Long timer

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    It's not a /2, it not a Ural engine or any of the east black clones. Camshaft position is a bit of a giveaway.
    It's what the poster says it is a BMW engine fitted with a CJ750 gearbox so that the more powerfully and considerably more reliable BMw engine will work with the CJ750 sidecar.

    What he wants to know is whether or not it is a 750 or a 600?
    #9
  10. crazydrummerdude

    crazydrummerdude Wacky Bongo Boy

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    Tell me how. It looks pretty damn close to a BMW engine to me, definitely the most BMW thing in the picture. The transmission, carbs, etc not so much.. but I have seen similar conversions of Urals (BMW engine mated to Ural transmission). I'm not saying it IS without a doubt a BMW, but if not, it's gotta be the best knock-off I've seen. Oh, and it looks NOTHING like a /2, that's for sure.

    The best way to tell what size it is.. is to measure the bore (and remember to put the valve covers on properly when you're done).

    My initial suspicion is that the intake spigots look significantly smaller than my 750, more like my 600. So, based on that alone, if I had to bet, I'd bet that it's a 600cc engine. I've thought of putting the 600cc badges (oh, and they're not plastic name tags, haha) on my 900 just to throw people off. :lol3

    I don't know if it's the low resolution of the pictures, but that exhaust sure looks like it makes a weird angle as it exits the head.

    But, anyways, looks pretty clean. So hopefully it's a solid bike.

    Your proper BMWs have the same hole.
    #10
  11. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    It's not a Chang Jaing or the "usual" Chinese Ural Clone-- those are either flathead/sidevalve or use the /2 camshaft location. I did a Google and didn't see anything like this engine. I dunno-- it's NOT a BMW engine, and the Chinese are the only other ones with the industrial capability to copy a clone. We'll see what the OP says. My take is that if yiou have BMW "Rxx/x" badges on anything besides a BMW product it's fraudulent and can't be good.

    :(

    --Bill
    #11
  12. crazydrummerdude

    crazydrummerdude Wacky Bongo Boy

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    Yeah, it's definitely not a CJ or Ural, but what makes you so sure it's not a BMW engine? I think all the collateral bits are throwing everyone off.
    #12
  13. Mark Manley

    Mark Manley Been here awhile

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    No not that way or you'll meet the knights that say ni to horizontally opposed twins!
    #13
  14. captainjohn

    captainjohn Adventurer

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    I'm sorry if I came in too strongly with assertion that it is not a BMW engine. The peripherals were not what made me say that, it was the position and and angle of the exhaust port more than anything else that sparked my response. Perhaps the Chinese have produced some replacement heads that will fit on a BMW barrel.
    #14
  15. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    In which case we'll don our HexHelmets and route them to the Squids who say Ekki-Ekki-Ekki-Ekki-PTANG. Zoom-Boing. Z'nourrwringmm.

    I've Googled and it's not like any BMW/Clone I've seen. May be a Chinese clone of a Zundapp design????

    The quest continues...

    --Bill
    #15
  16. Lornce

    Lornce Lost In Place

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    It's a BMW engine. No idea of the displacement, it could be anything from an R50 through R100, they all have identical outward appearance/dimensions.


    #16
  17. ritetwist

    ritetwist Been here awhile

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    EMW ? (With the red insignia) ?.
    #17
  18. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    Looking on the 'Net for a match, I tend to agree. The engine doesn't look "quite right", but it might be that the photos are "product shots" from a brochure and have been airbrushed ('Shopped) to look more appetizing, so they aren't real world kosher.

    The transmission is aftermarket since it has a reverse gear (hand lever above the shifter), along with the /2-style air filter built into the transmission top.

    We'll know more if/when the OP gets back.

    --Bill
    #18
  19. China2wheels

    China2wheels Been here awhile

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    Thanks again, guys. I am a total noob with respect to BMW airhead engines, so I thought I'd get some impartial advice from the experts around here.

    It is indeed a Chang Jiang with a BMW motor put in it.

    When I first got it, it seemed to have considerably less power than a 750cc conversion I had previously ridden. In fact, it had only slightly more power than the CJ's original 24hp engine.

    At first, I mistakenly thought it might be a 650cc (R/65), and I asked the builder. He replied with an offensive email, saying:

    "BMW doesn't make a 650cc boxer motor in that era, so again you are just showing ignorance."

    But maybe it is an R/60 (599cc) or maybe some franken-thing? It seems that the engine case across the R-line is quite close in dimensions? I have heard that the Chinese do indeed copy many BMW things, including the heads. Maybe it is a poor copy? The bike was built/converted in China.

    Again, thanks for your help. Appreciated.
    #19
  20. Big Bamboo

    Big Bamboo Aircooled & Sunbaked

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    I'm still curious what the VIN number on the case is...
    #20