To Re-use or Re-new the valve shims on a TR? | FerrariChat
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To Re-use or Re-new the valve shims on a TR?

Discussion in 'Boxers/TR/M' started by kerrywittig, Jan 10, 2009.

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  1. kerrywittig

    kerrywittig Formula 3
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    #1 kerrywittig, Jan 10, 2009
    Last edited: Jan 10, 2009
    Don't you just love it when someone re-appears on FChat and asks a million questions................

    I am about to do a valve seal replacement on my '87 TR............And as long as the engine is out, adjust the valves, replace the water pump and replace belts and tension bearings, blah, blah, blah.

    Question: Re-use some of the shims that may match up with certain valve values....... or.....when adjusting ONLY use the new shims where applicable. I ordered a full set of shim from Newco.....and they say DO NOT reuse shims........Fact or fantasy? A profit deal? I am suspisious.............
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    #2 Steve Magnusson, Jan 10, 2009
    Last edited: Jan 10, 2009
    Definitely don't reuse a shim surface against a cam lobe that has already been used against the cam lobe (the surface has already been work-hardened).

    If the underside of a shim hasn't been used against a cam lobe yet, it can be flipped over and used against a cam lobe IMO (if it's still in good shape -- no scratches, still has non-directional surface finish, etc.)

    But opinions will vary ;)
     
  3. kerrywittig

    kerrywittig Formula 3
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    #3 kerrywittig, Jan 10, 2009
    Thanks for the advice.

    I really was looking forward to making this $400 shim assortment I just purchased availabe to other QV owner to do their valve adjustment and mic up their "used" shims and pass on the kit. A sorta honor system cooperative. When I was a Maserati owners member this was done.......worked great and saved all those involved an arm and a leg.
     
  4. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #4 Rifledriver, Jan 11, 2009
    Its OK to do like Steve says. Just tell everyone to throw away the shims they pull out of the car that have been run on both sides and to make the appropriate contribution.
     
  5. fastradio

    fastradio F1 Rookie
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    #5 fastradio, Jan 11, 2009
    100% agreement...
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    #6 Steve Magnusson, Jan 11, 2009
    I should've added:

    If the underside of a shim hasn't been used against a cam lobe yet, it can be flipped over and used against a cam lobe IMO (if it's still in good shape -- no scratches, still has a non-directional surface finish, has good parallelism between the previously-used and yet-to-be-used sides, no cracks, etc.)
     
  7. 2dinos

    2dinos F1 Rookie

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    #7 2dinos, Jan 12, 2009
    FWIW:
    I had a fiat, and still Have a Lancia Zagato that were serious commute cars. The Fiat went over 210,000 miles before Bambi jumped in front of it totalling it, and the Lancia traveled 320,000+ miles. I tried to follow the valve shim theory of running only a new side against the lobe, but sometimes, I didn't because I was doing the service on a weekend, didn't have the perfect thickness in a new shim, and needed to use the car to go to work. I loved the way the Fiat tach would spin around the dial, it's where it made its best power and I hit redline routinely. After copious sprited use, I could tell that rod bearings were getting loose (lots of bottom end clacking), but the cams all looked to be worn about the same. Nothing stood out. Now, having said that, I still prefer to put a "fresh" surface up against the F-car lobe because it gives a sense of fresh surfaces to run in, but beyond that ????? IMHO - IMHO In the aircraft / aerospace industry we always went by surface finish when this issue would arise, 32RMS, 16RMS, 8RMS, 4RMS (highly polished) etc, and flatness. For a ground surface, it's probably on the order of .000050" or less. So, I would feel perfectly fine if I needed that specific size, and had a nice used surface. Again IMHO. :)
     
  8. rivee

    rivee F1 Rookie

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    #8 rivee, Jan 12, 2009
    On my 308 the shims were the same as a Volvo, along with other cars.

    The 348 uses the smaller shims. What other cars use the same size shims?
     

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