Now I know what the "F" in B230F stands for!

Discussion in 'General Motoring' started by Jamie, Jun 22, 2006.

  1. Jamie

    Jamie Guest

    Boy did I say the "F-word" once or twice today. Bob, the tool you
    showed me for depressing the valve springs was exactly what I could
    have used.

    OK - here's the deal on my valve shim job today:

    1) The plan: measure the existing shims to match the clearance
    measurements I have. Plug these into the formula to determine what size
    replacement shims to buy on Saturday.

    New Shim Size = (C-A) + B

    C = original shim measurement
    A = Spec clearance (.40mm)
    B = Measured clearance

    It is important to note the parenthesis because should you do C - (A+B)
    you get a different number.

    So - my formula will be: (4.00mm - .40mm) + .508mm = 4.108mm
    I'll buy 4.10 mm shims.

    Here is what I didn't like about this job and so I am going to take a
    calculated risk.

    All of my clearances were measured at .508 mm on cylinders 1-3 on all
    valves. Cylinder 4 measured .457 on each valve.

    I was only able to measure the first 3 shims (cylinders 1-2, valves
    1,2,3) because I did not have great tools to work with. Each shim
    measured 4.00mm. My vernier caliper was incremented by 1mm, so I made
    sure it wasn't 1/2 mm off by eye.

    Because the first 3 cylinders (6 valves) all had the same .508
    clearance, and the first 3 valves were all the same 4.00mm size, I am
    going to assume the next 3 shims are 4.00mm.

    That is the calculated risk. To be sure, after I replace the shims I'll
    take measurements to ensure I am within the .30 - .40mm cold clearance.

    I don't think I will do cylinder 4 at this time because I am not able
    to measure the shims. My plan is to drive 1.5 hours to the Volvo
    dealer and buy the shims I need. I will not have a kit.

    I may just buy that valve spring tool though. It is a pain using a
    screwdriver. I had to turn the camshaft to depress the springs, insert
    screwdriver, turn cam to release the lobe and hope the screwdriver
    held. Sometimes it did. Sometimes it slipped off.

    Jamie
     
    Jamie, Jun 22, 2006
    #1
  2. Jamie

    Jamie Guest

    Bob,
    I've decided to order the Tappet tool along with my shims from FCP
    Groton. I've decided to make my life a bit easier and have the right
    tool.
     
    Jamie, Jun 22, 2006
    #2
  3. Jamie

    hjsjms Guest

    Are you measuring the shim or assuming it is 4mm?

    The formula could also be (B - A) + C

    You could also just mike the total distance and subtract the required
    gap.

    Check EACH valve.
    Not a good risk to take. If you don't have the time and equipment to
    do it right then have someone else do it.
    See above.
     
    hjsjms, Jun 22, 2006
    #3
  4. Jamie

    Jamie Guest

    I physically measured 3 of the shims. Once I receive the valve tappet
    tool in the mail I will pull and measure each shim and recalculate.
    Because I had no tool, I could only get 3 off in about 2 hours.

    Because the 3 shims I measured with my caliper were all 4mm and the
    valve clearances for the 3 cylinders were all .508 - I will order all
    shims to be 4.10mm per the formula.

    Here's how I see it in the end:
    I'm going to get the right tool in the mail and a set of shims with it
    based on my risk. When I pull each old shim off I'll remeasure and
    recalculate. If all of the shims I ordered are the right size, I'll
    install them. If not, I'll send back the unused/unopened shims and
    drive to the local dealer and get the right size.

    Now that I have a tool on order, I can make sure each shim is measured.


    BTW: the shims in my engine had no markings. Do they wear off after a
    while?
     
    Jamie, Jun 22, 2006
    #4
  5. Jamie

    hjsjms Guest

    To save yourself some driving you might want to order some shims plus
    or minus one and two sizes from your estimate. Just return the unused
    ones.
     
    hjsjms, Jun 22, 2006
    #5
  6. Jamie

    Jamie Guest

    Thanks, good point. The last 2 valves measured .5mm less clearance, so
    I might order a few shims + or - .5mm.
     
    Jamie, Jun 22, 2006
    #6
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