Long stroke engine - attempted pre-oiling
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  1. #1
    Fellow Frogger! citroenthusiast's Avatar
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    Default Long stroke engine - attempted pre-oiling

    I attempted to pre-oil the long stroke engine I am rebuilding. Oil at full pressure shot out of the end of the camshaft splines. Is this correct or should the end of the camshaft have been plugged by the re-grinder?

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    Cheers,
    John T.

    54 11BL; 61DS19 LHM (son's); 71DS21 BVH; 73SM 3.0; 73SM 2.7EFI; 73SM 3.0 (other son's); 74 Maserati Merak

  2. #2
    1000+ Posts gerrypro's Avatar
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    What is to re plug? The cam shafts are solid!
    The oil may have come from the forward cam shaft supply passage feeding from the front main bearing. There is supposed to be a pressure restrictor in this. It is fitted under the main bearing upper shell. If this is absent the forward cam shaft bearing will receive too much oil.
    Cheers Gerry

  3. #3
    Fellow Frogger! citroenthusiast's Avatar
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    I checked my spare camshaft and sure enough, there is a oil feed hole from an undercut in the center of the first cam journal that leads to the counterbore in the center of the splines. If I blow into the end of the camshaft air whistles out of the side hole in the first cam journal.

    Just for grins, I fitted the stub shaft and (as long as I held the shaft in place against the oil pressure) the oil leak was reduced to a trickle that went back into the engine.

    It appears to be intentional, possibly to keep the spline connection lubricated?
    Cheers,
    John T.

    54 11BL; 61DS19 LHM (son's); 71DS21 BVH; 73SM 3.0; 73SM 2.7EFI; 73SM 3.0 (other son's); 74 Maserati Merak

  4. #4
    1000+ Posts gerrypro's Avatar
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    What year is this Long Stroke Engine? My experience is with the earlier engines without the harmonic balance.
    The cams I have seen are all solid. Is there an 'O' ring on the splined end? Maybe there were late modifications made.
    The spare parts book states that the 'O' ring was fitted until July 61. The illustration shows what I always thought was a centring cone in the end of the splines. There may well be a small bore in the depths of the centre cone.
    It is amazing that no matter how long that one has been involved with these cars, there is always something more to learn!
    Last edited by gerrypro; 31st July 2016 at 10:09 AM.
    Cheers Gerry

  5. #5
    Fellow Frogger! citroenthusiast's Avatar
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    This is a post September '61 "long spline" camshaft (i.e. a plate "1A" camshaft). As you can see, there is an intentional undercut in the cam journal with an oil feed hole in the undercut. The oil feed hole leads to the counterbore in the center of the splines. This version does away with the anti-rattle O-ring. It must be "oil damped" splines. Brilliant!

    Long stroke engine - attempted pre-oiling-oil-feed-1st-journal-1-.jpgLong stroke engine - attempted pre-oiling-oil-feed-1st-journal-2-.jpg
    Cheers,
    John T.

    54 11BL; 61DS19 LHM (son's); 71DS21 BVH; 73SM 3.0; 73SM 2.7EFI; 73SM 3.0 (other son's); 74 Maserati Merak

  6. #6
    1000+ Posts gerrypro's Avatar
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    Thanks I have not seen a cam like that before. There was probably one like that in my 65 DS19M Pallas. But I never had the motor apart in that car, and the only time I removed the gearbox and Bell housing was to replace a friction plate that tore its centre out. I did not closely examine the cam shaft.
    Cheers Gerry

  7. #7
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    In the cross-sectional diagram (Plate 1A Manual #456), I assume the diagonal drilling shown under the cam splines is a drain not a feed. Also, the diagram seems to show what looks like a scroll on the outside of the extension/stub shaft that resides in the bellhousing.

    Long stroke engine - attempted pre-oiling-dcam.jpg

  8. #8
    1000+ Posts gerrypro's Avatar
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    It also shows tat the splined section of the cam is pressed into the end of the camshaft. If this is the case it would have been easy to modify later cams with a counter-bore. The scroll is an oil return turbine.
    Cheers Gerry

  9. #9
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    So, it's not really designed to operate without the gearbox fitted. Without it, you would seem to have both no water pump drive and a large oil leak.

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