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Flywheel inspection plate question

Discussion in '308/328' started by Bizmark, Jul 23, 2025.

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  1. Bizmark

    Bizmark Rookie

    Aug 16, 2013
    19
    Alabama
    Full Name:
    Chris
    #1 Bizmark, Jul 23, 2025
    I was hoping to see if anybody would be willing to help with my dilemma. I recently acquired a 1982 308 GTBi and wanted to do a belt service on it so I would have an up to date record. I’m new to this so I had a long time American motor mechanic help me. The car was running and driving fine before the process but that driving was very limited due to my fear of driving with old belts. Maybe 3-5 miles. After we replaced the belts , which looked brand new of , the car isn’t running properly and will not hold an idle. We have checked timing marks, even though they are hard to see , and have the following question.
    From the fly wheel inspection plate I see a
    P M 5 | |
    The lines are after the PM5 not before like I’ve seen on Birdmans site and others. We feel like we are at top dead center and the pointer is on the line after the 5. Is this correct? Or are we missing something. We will take the valve covers off and inspect the cams but just wanted to see what you guys thought.
    Thanks, Chris
     
  2. DavidB_SD

    DavidB_SD Karting

    Sep 7, 2008
    64
    San Diego, CA
    Full Name:
    David B
    #2 DavidB_SD, Jul 23, 2025
    I have it in my head that you can see the mark on one cam through the oil fill on the rear bank (if you remove the cap). I could be wrong.

    Good Luck!

    -David
     
  3. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    37,108
    Cowboy Capitol of the World
    Full Name:
    Brian Crall
    #3 Rifledriver, Jul 23, 2025
    PM 5 is the wrong mark. PM1-4 is the correct one

    The internet is a poor place to get accurate information. Thats what factory technical information and shop manuals are for.
     
    Bizmark likes this.
  4. Dr Tommy Cosgrove

    Dr Tommy Cosgrove Three Time F1 World Champ
    Owner Rossa Subscribed

    May 4, 2001
    36,442
    Birmingham, AL
    Full Name:
    Tommy
    #4 Dr Tommy Cosgrove, Jul 23, 2025
    Would you mind telling me your chassis on the Bi? I have a database with each 2Vi car.
     
    prober34 likes this.
  5. Bizmark

    Bizmark Rookie

    Aug 16, 2013
    19
    Alabama
    Full Name:
    Chris
    #5 Bizmark, Jul 23, 2025
    Thanks Brian.
    I looked at my shop manual and after rechecking everything it looks like all my marks on the cams are correct.
    I’m to the right of PM 1-4 in between the hash marks. When I adjust the fly wheel from one hash mark or the other it really doesn’t change my cam marks.
    So hopefully that means I’m good. The car ran fine before but like I said it was sparingly driven. Once we put everything back together and it didn’t run quite right I got scared and wanted to verify all my cam marks. I actually verified the front bank first by pulling off the cover. Everything looked good so I put it back together. I used the oil cap hole to check the back upper cam. Once it was back together it still didn’t seem correct so I took the front off again and this time the rear cover as well so I could check the lower mark. I did notice a vacuum line was bad and broken in half. Maybe that was part of the problem. I’ll ordered another gasket set and put it back together. Thanks for your help.
    Hey Tommy ,
    This is Chris your local Ferrari friend. You already have the vin. It’s that yellow GTBi I sent you pictures of. I’m just getting around to doing the belts.
    I have a new addition you might be interested in checking out one day. I hope all is well with you.
     
  6. Dr Tommy Cosgrove

    Dr Tommy Cosgrove Three Time F1 World Champ
    Owner Rossa Subscribed

    May 4, 2001
    36,442
    Birmingham, AL
    Full Name:
    Tommy
    #6 Dr Tommy Cosgrove, Jul 23, 2025
    lol

    Hey, Chris !

    Send me a pic text of your new addition.
     
  7. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    37,108
    Cowboy Capitol of the World
    Full Name:
    Brian Crall
    #7 Rifledriver, Jul 23, 2025
    I get 5 and 1 mixed up all the time.
     
  8. Dockboy

    Dockboy Formula Junior
    Silver Subscribed

    May 11, 2013
    608
    Maryland
    #8 Dockboy, Jul 23, 2025
  9. miked

    miked Formula Junior

    Feb 7, 2001
    898
    Cincinnati, Ohio
    #9 miked, Jul 23, 2025
    When you see PM 5 l l you may be seeing the right hash mark which is for -3*. The left hash mark, next to the 5-8, is for TDC on cylinder #5. In any case it doesn't matter as all cam timing is done with the engine at TDC on cylinder #1. The little notches on the camshafts that match those on the cam bearing caps all are aligned while the engine is on TDC on cylinder #1. That has caught me a couple of times but I quickly remembered after scratching my head for a few minutes.

    Here are the flywheel timing marks on my engine, they all seem to be truncated at the bottom which leads me to believe that my flywheel has be heavily surfaced at some point in it's life.



    Image Unavailable, Please Login Image Unavailable, Please Login
     
  10. Bizmark

    Bizmark Rookie

    Aug 16, 2013
    19
    Alabama
    Full Name:
    Chris
    #10 Bizmark, Jul 24, 2025 at 8:23 AM
    Thank you all for your help
    I really appreciate it
     

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