Using a digital caliper instead of a feeler gauge for valve adustment?

Discussion in '4 Stroke Bicycle Engines & Kits' started by Bohemian_Lady, Aug 1, 2016.

  1. Bohemian_Lady

    Bohemian_Lady New Member

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    Is it even possible? I was on Amazon looking for a feeler gauge with the proper settings for my Huasheng. All of the ones I've com across have .0025 and .004 but no .003. I understand that the intake can be a very tight .004 but I'd like to have the valves as close to spec as possible. So is it possible to use a digital caliper, which I have, for valve adjustment instead of a set of feeler gauges?
     
  2. KCvale

    KCvale Well-Known Member

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    No.
    Feeler gauge combos are easy to use, you can set any gap to the 100th by simply using more than one strip at a time in combination for the exact value you want.

    Like a torque wrench, a simple but crucial tool to own.
     
  3. Bohemian_Lady

    Bohemian_Lady New Member

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    That makes sense, thanks for the reply.
     
  4. MEASURE TWICE

    MEASURE TWICE Well-Known Member

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    I may use a digital calipers to see what the feeler gauge measures as I let my feeler gauge get into too much weather. If it is off due to corrosion I want to know. I also I had learned by accident, the few brass thinner fingers of the feeler gauge can be squished with too much force. Sometimes the best way to learn..:(
     
  5. Tony01

    Tony01 Well-Known Member

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    Yes and no. If the digital calipers you have cost $5-10, then no. You need to have a way to measure thicknesses of different shims accurately. A coke can side is .0043", a manilla folder paper thickness is around .009" IIRC, business cards are usually about .011", and aluminum foil can be as thin as .001" sometimes IIRC. just get some feeler gauges. I have all the tools to accurately measure feelers but I still wish I had a set!

    Also when using feelers you want to get the point of very light resistance. Heavy resistance is too tight, little to no resistance is pretty loose. You do it and you'll understand what I mean. The feeler works on the "some resistance" size.
     
    #5 Tony01, Aug 2, 2016
    Last edited: Aug 2, 2016
  6. KCvale

    KCvale Well-Known Member

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    I have a cheap digital caliper I use all the time, but mostly just to measure round things and small lengths.

    I am really hooked on Metric, beats the heck out of base 12 fractions!
    And an actual Foot was set to use as a starting point and what shoe sizes were based on.

    https://en.wikipedia.org/wiki/Foot_(unit)#Historical_origin

    That's why fractions were so important in school.
    My feeler gauge set shows both sizes in each strip.

    So does my round spark plug gapper but I seldom use that anymore, I put NGK Iridium plugs in everything, they come pre-gapped with a cardboard sleeve on the end to keep the gap true but that is way off topic hehe ;-}
     
    #6 KCvale, Aug 2, 2016
    Last edited: Aug 2, 2016
  7. sbest

    sbest Member

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    I've used a dial indicator to set valve clearances.
    Put it on the rocker arm or follower bucket and see what you have for play.
    Very accurate.

    Steve
     
  8. KCvale

    KCvale Well-Known Member

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    Whats a dial indicator?
     
  9. sbest

    sbest Member

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    Here is the tool, a dial indicator and magnetic base. About $50 for acceptable quality. (all web photos)

    [​IMG]

    Here it is in acton on a car engine. Wiggle the rocker arm up and down and the needle will indicate the clearance.

    [​IMG]

    Here it is checking a crank. Support the bearings on blocks (I used magnets to hold them steady) and spin the crank. The dial will tell the truth. My well used 66cc engine was within 0.007" at the worst spot (crank cheeks, side to side). Freehand beating it with a brass hammer got it within 0.005" and less than 0.001" on the journals. It was less than 0.002" there before I started.

    [​IMG]

    Here is someone doing a HT crank in a lathe rather than on blocks. Either works, but I have a couple 2"x2"x4" steel blocks and 4 magnets.

    [​IMG]

    News flash, I've just bought another camera. I'll keep it away from salt water and whales this time. Unfortunately the cases are already stuffed with epoxy and the crank installed and closed up. I put the seals in backwards to further reduce crankcase volume and drilled a breathe hole to the back of the crank bearings to keep the oil flowing. Would have been nice to have pictures for you. Sorry.

    Steve
     
    #9 sbest, Aug 3, 2016
    Last edited: Aug 3, 2016

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