+ Reply to Thread
Page 4 of 4
FirstFirst 1 2 3 4
Results 31 to 36 of 36

Thread: Bitza Racing of early 90's

  1. #31
    Join Date
    Jul 2007
    Location
    Portugal
    Posts
    253

    Default

    I like big trails for big runs specialy with DUCATI engines

  2. #32
    Join Date
    Mar 2009
    Location
    France
    Posts
    329

    Default

    Some news...

    Last Wednesday we worked again on the bike.
    But if the disassembly was pretty well until now, news are not very good today

    We started by emptying the heads, removing bearings, gaskets, rockers, valves, etc.
    We didn't pay enough attention last time, but there were a broken head…
    As Glassman wants to use other heads for bigger valves it doesn't really matter for this engine, but he wanted to use them on another engine… and these “G” heads are quite rare… so it didn't start very well.











    A lot of half rings were broken, and the good ones were stuck in there groove (I have never seen that before...). A rocker is good for dustbin, and others need to be clean and check carefully, because they didn't looks in very good shape.
    It's not the good racing sparkplugs.

    A bearing scratched a little. In any case, all will be replaced.

  3. #33
    Join Date
    Mar 2009
    Location
    France
    Posts
    329

    Default

    We decided to start to empty the crankcase.
    We have two pairs of half crankcase to clean.
    The “90” which were on the bike, and the “9S” for R93.
    Glassman wanted to use the 9S for his project.
    But we only pulled them out of the cardboard.
    I checked the area where they are fragile (left crankcase) and see a horrible crack between the crankshaft bearing and the one of the distribution countershaft (the crack continues beyond).

    Kaputt…

    After removing the studs, we put the “90” crankcase in an oven to heat them and pull out the bearings.



    We finished by cleaning them and discovered traces of a broken chain, fixed with seal paste.
    I think it’s easy to do better to fix it properly…





    There were other traces of this incident on the clutch slave. It missed a piece, and there are two little cracks on the fitting holes.
    For our respective project, I have exchanged with Glassman a 92-93 slave clutch with this one (for 851).
    Even if it can work, I will keep searching a perfect one for my R91.



    The worst is yet to come…
    When we removed the bushing of the left crank bearing, we found something strange…
    In the moment, we think of a dremel clearance around the oil hole.
    But after a mail exchange with Phil911 the evening after I understood what it is.

    After spoken about the cracked 9S, he explained me that it is classical, due to a bushing turning in its housing, which are eating the metal around the hole and cracking the crankcase…
    Exactly this kind of snatching of material... which is on the "90" crankcase.





    Not really what we expected...

  4. #34
    Join Date
    Mar 2009
    Location
    France
    Posts
    329

    Default

    The kill switch is tinkered too.

    So I have disassembled it to clean it and fix it correctly.

    I can compared with mine.

    The red button isn't correct and wiring is patched.









    Black and white to one extremity...


    ... Red and blue to the other !!

  5. #35
    Join Date
    Aug 2007
    Location
    Cornwall S.W. England
    Posts
    5,066

    Default

    Hi Baba,

    I'm enjoying following this thread finding it very interesting, please keep the updates coming.
    I find it hard to understand how the fretting can result in a hole around the oil feed hole can look like that?
    Can you explain any further?
    I'm not surprised about the damage that you've found so far, it's to be expected with a race motor that's been pushed to it's limits time and time again.
    I once warned a forum member to factor in the cost of a rebuild if he were to buy an ex race motor, to me it seemed like fair/sound advice? But...
    A forum member who owns an ex race bike got rather upset by my post.

    Steve R

  6. #36
    Join Date
    Mar 2009
    Location
    France
    Posts
    329

    Default

    I don't really know the phenomenon.
    But a hole is an area of stress concentration.
    Oil under pressure with the turning bushing probably attack the crankcase where it is more fragile, around the hole.
    After a while, the crankcase finally breaks.
    I'm not sure how it happens, I see it like that, but someone have may be the explanation... Phil ??

    Don't worry for the updates, I will give them after every work on it.
    If I find the time, I'll make also a post on my R91...This is expected in any case, the question is when.

+ Reply to Thread

Similar Threads

  1. Ducati 851/888 racing early alu dash
    By ajcorse in forum For Sale
    Replies: 2
    Last Post: 12-05-2014, 02:40 AM
  2. Replies: 0
    Last Post: 06-03-2014, 07:14 AM
  3. Early 851 racing mods.. PDF
    By stiglarsenDK in forum Files
    Replies: 3
    Last Post: 06-03-2012, 06:57 AM
  4. Replies: 0
    Last Post: 05-26-2012, 03:37 AM
  5. Ducati Racing Original Racing Parts
    By desmax888 in forum Links to 851's and 888's for sale
    Replies: 2
    Last Post: 02-10-2011, 06:02 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts