Cam Timing | FerrariChat

Cam Timing

Discussion in 'Boxers/TR/M' started by Nick G48, Feb 28, 2021.

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  1. Nick G48

    Nick G48 Karting

    Aug 18, 2016
    57
    Clinton Township, Michigan 48316
    Full Name:
    Nick
    Have the engine out of my 86 TR for the 30K. Presently doing the Valve Timing procedure. I feel comfortable that we are doing the procedure and measuring valve clearance correctly. Here is my question: We determined the size shim to use on number 1 and number 7 for intake and exhaust. Example: One shim will be 3.93. Since a standard shim is 3.90 and 3.95, can I use either one or do I have to grind a shim to 3.93?
    I thought I read somewhere that you just use the next closest size. If this true?
    Thanks for the help
     
  2. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    8,866
    southwest germany and thailand
    Full Name:
    romano schwabel
    you are right with the standard shims with 3,90 and 3,95 - but when you meassure you see sometimes that they are not 100% correct, so plus/minus 1/100 in not unusual

    so when you do the adjustment not only check when intake and outlet valve will open, also when will close. and when you then have the ° when opening and closing same far away than standard you are right
     
  3. Tegethoff

    Tegethoff Formula Junior

    Jul 19, 2014
    301
    Los Feliz
    Full Name:
    Adam
    If you're not grinding shims to fit use the smaller size, I.e. 3.90 for a 3.93, better to lose a bit of duration than the alternative.

    IMHO, you're looking at .0011" vs .0007" either way, not enough to get too concerned about for a street driven engine.
     
    turbo-joe likes this.
  4. Nick G48

    Nick G48 Karting

    Aug 18, 2016
    57
    Clinton Township, Michigan 48316
    Full Name:
    Nick
  5. Nick G48

    Nick G48 Karting

    Aug 18, 2016
    57
    Clinton Township, Michigan 48316
    Full Name:
    Nick
  6. Nick G48

    Nick G48 Karting

    Aug 18, 2016
    57
    Clinton Township, Michigan 48316
    Full Name:
    Nick
    Thank you for the information
     
  7. Nick G48

    Nick G48 Karting

    Aug 18, 2016
    57
    Clinton Township, Michigan 48316
    Full Name:
    Nick
     
  8. Nick G48

    Nick G48 Karting

    Aug 18, 2016
    57
    Clinton Township, Michigan 48316
    Full Name:
    Nick
    Thanks. I ordered a complete set of shims today from a company in Germany. I should have every size that I need
     
  9. Nick G48

    Nick G48 Karting

    Aug 18, 2016
    57
    Clinton Township, Michigan 48316
    Full Name:
    Nick
     
  10. Nick G48

    Nick G48 Karting

    Aug 18, 2016
    57
    Clinton Township, Michigan 48316
    Full Name:
    Nick
    Thanks for the info. Much appreciated
     
  11. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    8,866
    southwest germany and thailand
    Full Name:
    romano schwabel
    would be good if you will fill out your information to know in what area of our small world you are living. then I think you will get some more detailed help. also would be great to introduce yourself a little
     
  12. Veedub00

    Veedub00 F1 Rookie
    Owner Silver Subscribed

    Jun 30, 2006
    4,887
    Troy, Michigan
    Full Name:
    James
    Nick's in Metro Detroit. I helped him pull his motor a few weeks ago. He has an '86 Black Testarossa.
     
    Nick G48 likes this.
  13. Nick G48

    Nick G48 Karting

    Aug 18, 2016
    57
    Clinton Township, Michigan 48316
    Full Name:
    Nick
    I added info. I am located in Michigan, near Detroit
     
    turbo-joe likes this.

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