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Thread: Cam Tower Oil Spray Bar/Tube Cleaning

  1. #1
    Junior Member
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    Cam Tower Oil Spray Bar/Tube Cleaning

    Anyone ever cleaned their cam tower oil spray bars - as in an early 911 ('69 911E)? I wasn't able to find anything here using the search field (using various combinations of "cam tower", "oil spray bar", "spray tube",....)
    There are descriptions of doing it on PP's forums, but those are on later engines, and I'd like to find out if they are valid for mine. The PET only shows an early 912 cam tower (and w/o an oil spray bar or plugs). They suggest drilling the end plugs, tapping the plugs, and then pulling them. Specifically, I'd like to know what the dimensions are for the plugs on either end of the tubes - so I know how deep to drill/tap (they look to be only several mm in dia).
    thanks,
    cheers,
    jt
    jt69
    '69 911E

  2. #2
    Member #226 R Gruppe Life Member #147
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    I use a 5mm drill and 6x1.0mm tap. the drill will not touch the spray bar if you are close to center. then use a 6x1.0 bolt, large washer, nut and a socket and pull the plug. the spray bars need a little coaxing to get out and only go back in one way, confirm rotation of the spray bar. drill size is tap diameter minus the thread pitch, 6mm tap - 1.0 thread pitch = 5mm drill. Gled

  3. #3
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    Thanks Gled. Yeah, that's what someone on PP's forum said to do, but I didn't know if it might work on my engine. I just made some measurements and see that the spray bar is about 8mm dia, and has a thin wall. So using a 5mm drill bit should be fine.
    Couple other things:
    1. What did you use to plug it back up with? I've seen suggestions of using a 6x1.0 plug, blue loctite, and be sure they don't stick out beyond the face. Other's suggested getting replacement plugs, but the PN's they give are for the 930 & 964's.
    2. Why not just pull the plugs on both ends and leave the tube in the tower when you clean it? I'm thinking there'd be less danger of dinging it, and wouldn't have to worry about the orientation getting messed up.
    3. There also appears to be a 4mm plug about 5.5" from one end of the tube (8.5" from the other end). This looks to be about where the 964's have a screw for keeping the tube from rotating. Did you encounter this?
    thanks again,
    cheers,
    jt69
    '69 911E

  4. #4
    Restoration newbie.
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    Depending on how early your spray bars are you may have only 2 spray holes per rocker. I modified mine to have 3 like the later versions while I had them out for cleaning.

    andy
    67S in pieces
    EarlyS: 1358
    [SIGPIC][/SIGPIC]

  5. #5
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    Hmmm... 2 holes vs 3 per rocker. That's a thought. Hadn't heard anyone else mention that. One of the main issues I'm facing now is that I had some heavy pitting on a few of my cam lobes and some of my rocker feet that ride on the lobes. Plus some of the rocker shafts and their bores were badly scored. Engine did have 99K on it, and spun the #2 rod bearing. Anyone else have a comment on any of this?
    thanks andy,
    cheers
    jt69
    '69 911E

  6. #6
    Early spray holes went out in 67
    You should have nine hole bars
    1966 911 #304065 Irischgruen

  7. #7
    Member #226 R Gruppe Life Member #147
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    Plugs are available from Porsche and are the same as 964. I remove plug from back side so exactly flush doesn't matter. Little burs inside tubes catch pieces of debris and plug holes.

  8. #8
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    Hmmm... As best I can count them (I don't have the bars out yet - just the cam towers off the heads), I've got 1 hole for each rocker (1 per intake, 1 per exhaust), which makes 6, plus 1 I believe, for each of the 3 bearings. That would make 9.
    Andy: where did you add holes?

    Gled: Thanks for the comment on the 964 plugs being useable in my '69. I was wondering about that. What do you do - just tap them back in (and no leaks?)?

    cheers,
    jt69
    '69 911E

  9. #9
    Member #226 R Gruppe Life Member #147
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    its a little more than a tap. careful application of loctite to seal, I chill the plug and heat up the cam housing and drive the plug in. Look carefully with a small mirror at the exhaust side of the spray bar, are you sure there aren't two holes on the bottom. I would modify spray bar if there aren't 2 on the bottom.

  10. #10
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    I stand corrected - there are 2 +1 holes for each location. The 2 are slightly rotated from each other, with the 1 rotated further. So when I flipped the cam tower over to see the others, I thought I was seeing only a total of 2. Thanks, good to know.
    I hear you on the plug, but I'm going to hold off on that for now -- carb cleaner runs freely thru the bars, and out all the holes, so I may not remove the plugs after all... I should get back to starting my reassembly per the order in Wayne's book - now that I have all the parts, gaskets, sealants, etc. So that takes me to figuring out how to best clean out the crank oil journals. I need to do some research on that (hopefully there's some threads on doing it).
    thanks again,
    cheers
    jt69
    '69 911E

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