New 336° cam from BMW

Discussion in 'Airheads' started by RGregor, Dec 24, 2012.

  1. RGregor

    RGregor Been here awhile

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    In an early thread from 2011 Moorespeed reported that he had discovered that the latest batch of BMW's 336° cams were scrap.
    The means to identify them were the improper grind and that they came in a thick yellow/ opaque plastic bag

    I bought a 336 this year.

    The cam was wrapped in anti-corrosion paper and came in a transparent plastic bag.
    The label shows "Made in Germany".

    I did not check the draft as I don't have the equipment. I'll do it during the week.

    As pre-info:

    The cam shows the following markings.

    The front face is marked with "247" and "336°".

    The base circle side of the exhaust valves is marked with (from front to back-side)
    A symbol (looks like two "0" letters (not perfectly round at the corners) leaning together and touching at the upper side)(*)
    In the center of all four lobes the number "055"
    Befor the last lobe the number "6".
    All letters are kind of stamped into the cam.

    On the opposite side at the front the number "396" (last three letters of the part number?) and in the middle a "I".
    These letters are projecting out of the material.

    The interesting thing:
    The symbol mentioned here (*) also shows on the Schleicher cams I have had in hands. Or the 330° I still have here. All other markings are different or at different locations.
    I'll try to find out if this is a mark being characteristic for Schleicher cams.

    Maybe the markings listed above could be a means to identify the misground ones.
    I know that some adventurers have a 336 lying around. Also from old stock. I think that e.g. SS mentioned that once.
    Can anyone check the markings?
    Maybe Moorespeed still has one out of the chinese batch and can compare?

    The old thread:
    http://www.advrider.com/forums/showthread.php?t=688182
    #1
  2. moorespeed

    moorespeed Adventurer

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    I do not have any of the bad cams left BMW gave me my money back and a little more, but they kept selling the cams, i think they had about 400 made, and because it was a part for an old bike they thought the chances of them coming back under warranty was small due to the small amount of miles that most of the owners do, and they can always blame the followers. If you hold the cam and put a vernier accross from the base to the top of the lobe at the edge then move to the other edge you should see the lobe has a taper, if it is flat or almost flat it is scrap, cant see why you want to run one anyway.
    #2
  3. Rob Farmer

    Rob Farmer Long timer

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    I've an original set on the desk next to me being used as a paperweight.

    247 and 336° stamped into the nose of the cam. 216 cast into one side of the body of the cam and on the opposite side there's a symbol that looks like a pair of squarish butterfly wings (as per your description) and then 055 further down and then a 2.
    #3
  4. RGregor

    RGregor Been here awhile

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    Hello Mr. Moore,

    I will measure the taper as I'm not sure.
    Why do I want to try the 336?
    I do have some personal experience with Schleicher cams (324° and 330°) and none with the 336.
    Not a good basis for argumentation.
    And I'm simply curious and want to know. And the cam is cheap.

    Edit: I also had used a cam from Dirk Scheffer (symmetrical 333° cam) for a while. I believe I know what to expect from the 336 but knowing is better than believing.

    Merry Christmas and a Happy New Year to you.

    Best regards

    RG
    #4
  5. RGregor

    RGregor Been here awhile

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    That's the symbol I mean.
    #5
  6. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    RGregor, thanks for the most excellent discussions on camshafts of late. Very informative.

    That is distressing. :(

    Y'all have a Merry Christmas and a Happy New Year!

    --Bill
    #6
  7. chasbmw

    chasbmw Long timer

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    My newly delivered 320 cam was delivered by Motoren Israel recently .

    It has 247 and a 7stamped into the middle of the pair of cam lobes. And then up by the front of the cam there is RO240.6 followed by what I assume is the Schleicher symbol: an S inside a wankel shaped (best description I can think of) triangle.

    Would BMW allow Schleicher to put their symbol on 'BMW' cams such as the 336? Probably not I think.
    #7
  8. AntonLargiader

    AntonLargiader Long timer

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    I don't see why they wouldn't. Many BMW parts have the maker's mark on them.
    #8
  9. RGregor

    RGregor Been here awhile

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    Hello Charles,
    that's interesting. Five years ago I bought my Ro.340.10 (330°) directly from Schleicher. It has the same butterfly symbol than the BMW 336 cam. Can't check the 324 as it is hidden in the engine, but I do remember some other cams with that logo. And some others reporting that / referring to that symbol as well.
    Never seen one with the Schleicher "S". The 330° has just the Ro 340.10 stamped on it (between the seat for the sprocket and the first lobe) but no "S".

    I sent an email to Schleicher asking about the butterfly.
    #9
  10. supershaft

    supershaft because I can

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    So it seems the 336's are still made in Germany and are ground to spin the lifters? :clap I have still only heard one direct report (albeit on the internet) of bad 336's. Pj said Jim Cray said he knew about the issue but I didn't understand if he had experienced it himself or had just heard about it through Moorespeed I suspect? If you still need me to look at any markings on my ten year old brand new BMW 336, I will.

    Why would I want to run a BMW 336? I love the way they make airheads perform! I also love how they last. After 70,000 HARD miles with my 336, the only thing I needed to replace during a valve job other than the normal valves and guides were my titanium valve spring retainers. They were hammered. The 336 is a great all around cam. Great MIDRANGE with good low end and top end.
    #10
  11. pommie john

    pommie john Long timer

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    I can't remember now whether he had bought one or heard about it.

    As for why anyone would want to use a 336? Everything that can be said has already been said here :)
    #11
  12. supershaft

    supershaft because I can

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    As usual, thanks for your input pj!
    #12
  13. RGregor

    RGregor Been here awhile

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    If it's still or again we can't say. And still I haven't measured mine.
    The basic idea behind posting the markings was to find out if there were major differences. Maybe some cams bought between 2009 and 2011 are still lying around unused.
    If anyone had a cam with completely different markings (e.g. without the butterfly) then we could measure the taper there. And maybe find an easy rule which cam not to use.

    Having a close relation to BMW I would not be disappointed if there were no problems.
    But I can't believe Moorespeed was on drugs or invented the whole story :-(

    Please do.
    #13
  14. CraigC

    CraigC Adventurer

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    750cc motor about to go back together. Wossner pistons, pocketed for 336 cam. Decked, ported/polish, bench flowed heads. Should I buy a new cam? Tag is dated 02/2009.

    [​IMG]

    [​IMG]

    [​IMG]
    #14
  15. RGregor

    RGregor Been here awhile

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    Good question.
    The label says "Made in Germany". AFAIk that only means that at least one step of production has to be performed there.
    The cam has the butterfly logo (leftmost marking).

    Any chance you can measure the taper?
    I don't rely the result I get with MS's method.
    I'll do it with the cam fixed in a lathe and a gauge on the saddle (don't know if it's the right expression.
    "Support" in german) measuring height difference between the two sides of the lobes.
    #15
  16. Renner

    Renner combustophile

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    same as what we call the 'carriage'

    looking for a taper across the face of the lobe, reference parallel to the axis of the cam shaft. yes?
    #16
  17. RGregor

    RGregor Been here awhile

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    Thanks for the wording.
    Very often I'm not sure if I really express what I want to ...

    Looking from the side the lobe should not look like a rectangle but, the top face is under a small angle relative to the centerline.
    #17
  18. supershaft

    supershaft because I can

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    My BMW 336 that I got around ten years ago is marked pretty much like the one in the photo above. It has lobes that are a little higher on one side just like a 308 that I have on my desk. I measured them with a caliper.

    Is that the 'yellow' bag the 'Chinese' cams come in? I have seen parts bags like that for decades. I am still hoping Moorespeed's experience was a fluke. One thing I do know for sure is that I have seen other parts sold by BMWAG more recently that are crap but, so far, just about everything Moorespeed has said about the 336 newly produced or otherwise sounded like he made it up to me based on my experience with them and other inmates experience with them as well. Can't see why you would want to run one? If I had found that they make less power than a 308 under 6000 rpm I wouldn't want to run one either but that isn't even close to what I have experienced. Quite the opposite actually! My experience with them is more like pj's, mattcfish's, robtg's, and Dr. Curve's, for instance. I am here trying to make sense out of a story that so far makes little sense to me even though it is getting quite a life of its own but that isn't the first time I have seen that happen.

    It's great that you bought one to see what is actually going on. The last one I bought was about four years ago! I put it in a R90 with some Dell's and high CR pistons. Just a month a ago that guy told me yet again that he LOVES the setup.
    #18
  19. mattcfish

    mattcfish R90X

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    Dumb question, what do you mean by "scrap"?
    The yellow bag cams are defective...how? Bad hardening?

    I've got a used 336 in my /6. Love the performance, but not sure how old it is, or from what batch.
    #19
  20. RGregor

    RGregor Been here awhile

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    Does it have the butterfly symbol?
    #20