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308 2V cam drive pulley ring nut removal

Discussion in '308/328' started by bl10, Sep 10, 2020.

  1. bl10

    bl10 Karting

    Jun 8, 2011
    108
    Hey guys. I'm changing the cam drive pulley bearings and seals on my 308 2V. Had no problem getting the ring nut off the rear pulley once I got the ring nut tool and a godzilla impact wrench (over 1000 ft lbs of break away tourque). The front bank ring nut is another story.
    The impact wrench just bangs and nothing moves. Its actually elongating the slots on the ring nut.
    I tried heat (not to much but plenty hot map gas) and no luck.
    I am soaking it with blaster but don't have much hope it will help.
    I'm about to take my Dremel and chisel to it.
    Any suggestions?

    Thanks
    Barry
     
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  3. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    10,634
    San Carlos, CA
    Full Name:
    Mitchell Le
    Get a replacement ring nut.

    Then, carefully slice the old one with a dremmel tool. Eventually it lets go when the cut is deep enough.
     
  4. bl10

    bl10 Karting

    Jun 8, 2011
    108
    Thanks

    I have replacements already. I was just hoping someone had some magical solution. I can't believe how tight this thing is. Must be rust or something.

    Barry
     
  5. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    2,612
    Mark it. The impact wrench is probably moving it.
     
  6. bl10

    bl10 Karting

    Jun 8, 2011
    108
    That's what I hoped but its not moving. I ran the impact for a long enough time I was worried about damaging the connecting gears. I'll try it once more with the penetrating fluid and if no good will cut it off. This has been a long drawn out process (see my post on bent exhaust valves). https://www.ferrarichat.com/forum/threads/dumb-is-as-dumb-does-exaust-valve-head-gasket-replacement.625552/#post-147334522 and I thought I was home free with the rear head reassembled and installed with new valves, shims and seals. This thing is kinda like the stock market, lots of ups and downs. I'm also changing the belt system from the Ferrari square tooth belts and pulleys to Derek White's round tooth belts and pulleys. In my opinion the round tooth pulley system is far superior as the belts are much stronger and last longer along with the adjustable aluminum pulleys which, of course, leads me to degreeing the cams. I'm toying with the idea of opening the lobe centers 4 degrees which would help the idle (its a carb car) and midrange a little.



    Barry
     
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  8. sltillim

    sltillim Formula 3
    Silver Subscribed

    Nov 22, 2009
    1,259
    San Diego
    Full Name:
    Spencer Tillim
    A little help from a heat gun never hurt anybody.... be careful with your old (possibly plastic) pulleys if you plan on keeping them. I already have Derek's parts and looking forward to putting them on. Can you include pics / notes / challenges of your lower pulley install?

    Thank you!
    Spencer
     
  9. bl10

    bl10 Karting

    Jun 8, 2011
    108
    Spencer
    I have completed the install on the rear head and am now working on the front. So far all is good. My car is a 1978 GTS 2V (carbs) kinda right in the middle of changing from the open to sealed outer cam drive bearing which created a couple of questions but no problems. At first I had a problem with the drive pulley hitting the front cover but it turned out to be the way I installed the outer cam bearing. I forgot the spring washer when I installed the bearing so I put it on the outside of the bearing rather than the inside which moved the cam drive bearing in about 40 thou and caused the interference. Originally I thought the pulley wasn't chamfered enough so I increased the chamfer. Not sure if that's necessary as after removing the cam drive bearing and installing another one correctly the pulley no longer hit the front cover. It was, however, very close so I got some 15 thou shim washers and shimmed the pulley 15 thou away from the bearing just to be safe.
    I'm using the eccentric bushing to adjust cam timing and found the bushing fit to be to tight so I enlarged the bushing hole in the pulley slightly. Probably not necessary but it makes it easier to make adjustments. Other than that everything has gone together with no problems.
    I'm doing one head at a time so I can be sure the cam timing is close via the factory marks on the cams and cam saddle. I lined up and locked the front head cams with paper under the saddles then installed the the rear cams using the factory marks. I rotated the engine several revolutions with the starter to check belt alignment and cam timing . Now I'm reversing the process for the front head. After both heads are assembled I will degree the cams just because I want to as the factory marks have proven to be pretty good.

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  10. derekw

    derekw Formula 3

    Sep 7, 2010
    1,318
    London, UK
    Full Name:
    Derek W
    I'm having the same problem with the spare engine I'm now taking apart. I'm worried about all that impact on the gear teeth so am going to Dremel slots if the heat gun doesn't work.

    After anodising the pulleys, those eccentric sleeve holes are a bit too tight. I just ran a round diamond file through a few times which worked. One 308 owner here got charged £120 by his high-end Ferrari specialist for doing that 2 minute job on his four cam pulleys! (picture for those who haven't seen my splendiferous invention)
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  11. bl10

    bl10 Karting

    Jun 8, 2011
    108
    So heat and penetrating oil did no good so I went at it with my Dremel and chisel. Ground all four slots and got it off using ring nut socket with nothing more than a couple of nicks on shaft. Odd thing about it is it did not have washer between nut an pulley which may be the reason I couldn't get it off as the ring nut tool was digging into the pulley. I'm sure it came from the factory this way.

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  13. bl10

    bl10 Karting

    Jun 8, 2011
    108
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  14. Tonksy1

    Tonksy1 Karting

    Jun 21, 2016
    88
    New Zealand
    Looking forward to getting my set of cam pulleys on also. Dereck sorted me some for my 83 qv.
    Keep us updated with anymore tips you may have with the install. I'm about to attempt removing the bottom drive pulley nut tomorrow, fingers crossed...
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  15. wilkrod

    wilkrod Karting

    May 9, 2012
    98
    Ocala, Fl
    Derek,
    How can I get a set of these pulleys for my 83 QV?
    Thanks
    Jeff
     
  16. derekw

    derekw Formula 3

    Sep 7, 2010
    1,318
    London, UK
    Full Name:
    Derek W
    Just send me an email to derekrwhite at yahoo dotcom ("r" in the middle.) I have a couple of sets left. The QV and 328 is a little more work to fit if you want to use the Gates racing blue belts-- T288rb and similar 116 tooth belts may need the slot in the tensioner bearing holder lengthened. Most have used 115 Gates GT2/3 belts as I don't think they make a 115 tooth racing belt.
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