How to Use Plastigage to Check Rod Bearing Clearance

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ความคิดเห็น • 22

  • @danthatguy9686
    @danthatguy9686 3 ปีที่แล้ว +1

    3:48 yes thanks a bunch for asking that. Noone addresses this 👍

  • @eallanboggs
    @eallanboggs 3 ปีที่แล้ว +2

    I looked it up in my 3.000 page Helm shop manual. It says 0.0008 to 0.0025 That's 8 to 25 ten thousandths. Mine all measured at 20 ten thousandths using plasticgage. They all looked good. I changed all the rod bearings but not the mains

    • @MicsMotorworx
      @MicsMotorworx  3 ปีที่แล้ว +1

      Neat. As we understand, there are different clearances for different generations of LS, and engines in general. Glad yours was good. Thanks for watching.

  • @Jaredsarusrex
    @Jaredsarusrex 3 ปีที่แล้ว +1

    It doesn't bug you guys that you used a cordless drill to tighten down those caps? When using plastigauge I always use torque wrench to specific foot lbs

    • @MicsMotorworx
      @MicsMotorworx  3 ปีที่แล้ว +2

      We initially set the caps in place with a low torque settings on the electric impact. It's fine to do that when it's not set near or over the recommended specs.
      Little Jon then went back and set the cap in the proper sequence with the proper specs. Thanks for watching and for the feedback 😊

    • @Jaredsarusrex
      @Jaredsarusrex 3 ปีที่แล้ว +1

      @@MicsMotorworx good to know thank you 😊

  • @eallanboggs
    @eallanboggs 3 ปีที่แล้ว +2

    You said the GM is 23 to 76 thou You did the rod and it measured 5 which is out of spec(too low), but you said it was OK. Am I on crack or is it too tight? 5 is less than 23 or did I flunk basic math?

    • @MicsMotorworx
      @MicsMotorworx  3 ปีที่แล้ว +1

      Yes. Jon did misspeak there. He should have stated 5 ten-thousandths when looking at the reading. 0.0005.

  • @BH-cg8ds
    @BH-cg8ds ปีที่แล้ว

    I'm very sorry for asking a question that you might be considered stupid..
    Also I know the video is 2 years old
    So please don't judge me on it..
    I have a Ford 3.5l Ecoboost engine still in the car that i was told has a slight rod knock..
    I've never heard of a slight rod knock but I was hearing it and it's not exactly loud like other engines that rod knock and it definitely sounds like one though..
    Anyway...
    I have already removed the oil pan and all the rod caps the Crank looks very good & is well within tolerances but 3 of the 6 connecting rod bearings have some wear and scuffing/ imbedded bits that appear to be from lack of oil maintenance..
    Do I use the plastiguage with the old bearings to get my clearances?
    Or do I have to get a set of standard size connecting rod bearings and install them and then use the plasti gauge to check the clearances ?
    I assume I would use the old bearings even though they are worn out and would obviously have a bigger clearance than the ones that aren't but I'm very confused about it and can't get an answer from anyone anywhere else so im hoping and praying that you will take the time to respond to me on this video..
    Also the main bearings and journals have no indication of damage or wear and no scuffing or anything...

    • @MicsMotorworx
      @MicsMotorworx  ปีที่แล้ว

      Great question and thank you for reaching out.
      This is Mike. If it were me doing the work, I would measure (mic) the journals and mains on the crank to ensure proper diameter and use a new set of bearings for measuring clearance with Plastigauge. Definitely cross-reference your measurements with good source materials.
      I'll ask Jon for you and follow up with this reply if necessary.
      Good luck.

    • @MicsMotorworx
      @MicsMotorworx  ปีที่แล้ว

      Checked with Jon. He said, "Yes. Always check your clearance with new bearings."

    • @BH-cg8ds
      @BH-cg8ds ปีที่แล้ว

      @@MicsMotorworx
      So I should order a full set of standard size connecting rod bearings and use them ?
      I know I should use precision tools for the measurements and all and then double check with the plastiguage but I don't have the tools on hand so can I get close enough If I purchase full set of standard rod bearings and then stall them and use plastiguage And if I need oversized or undersized bearings for some reason I would have to order another set with the right clearances correct ?
      I'm asking because I'll try and get the right tools but just in case I don't or can't get them is that the next best option?
      Thanks for your help and support..
      I've reached out to other people on TH-cam and your the only one that responded back and I really appreciate it so much..
      Thanks again for your time.
      Hope you have a very blessed future. .

    • @MicsMotorworx
      @MicsMotorworx  ปีที่แล้ว

      Fortunately, bearing materials are softer than the crank. Tools help free up uncertainty. Plastigauge is a tool. A machinist would recommend things specifically detailed. A shady-tree mechanic would recommend something else. It all depends on your knowledge and ability.
      I would mic the crank. Advance and Autozone have a tool rental program. But if you can't get the reight tools, measure with pg. Start at 0 then turn the crank 90 deg and measure again. Repeat for 180 and 270 deg. Check for consistency and inconsistencies. Honestly, though. Oversized bearings should only be used when the crank has been turned. If the bearings ate the crank enough to require oversized bearings, it'll need to be turned at a machine shop.
      Good luck.

    • @BH-cg8ds
      @BH-cg8ds ปีที่แล้ว

      @@MicsMotorworx
      Thanks so much for your help...
      And thank you for responding...
      I do have some sound clips or videos of what the engines doing The noise it's making the knocking sound would you be interested in listening to that Tell me what you think it might be ?
      Think I'm going to follow your advice That's how I'm going to handle it and doesn't like to cranks all chewed up and it doesn't even look like a bearings spun When I remove them they were all sitting where they should be to crank doesn't look all chewed up maybe some minor scoring on it It's basically so light that I can't feel it..
      Not sure if there's any way to PM me or for me to PM you instead of sending messages through their comments on your video..

  • @razoreyes45k
    @razoreyes45k 2 ปีที่แล้ว

    The correct language to Engine Building measuring specifications (in written form) is in numerical form.
    Example:
    A .030 over 4 inch bore = 4.030 inches.
    Oil Clearance to a Rod Bearing (in theory) = .0025
    Some more:
    .0035 = Three and a half thou
    .0002 = Two tenths
    No active machinist or Engine Builder says "Ten Thousandths". Unless you are stuck in a classroom.

  • @razoreyes45k
    @razoreyes45k 2 ปีที่แล้ว

    This procedure (while may net you successful results) is not recommended. Engine Building is measured in .0001 and .001 inches.

  • @razoreyes45k
    @razoreyes45k 2 ปีที่แล้ว

    This repair may last a while but it will not last. If you measure the oil clearance in the Rods, what about the clearance in the Mains and the bores?
    I worked in a engine repair/rebuild shop with a professional mechanic who worked separately from the machining operations. Never did I see him measure and change Main Bearings in any vehicle. The Long Block was removed and the engine torn down completely. All parts cleaned, inspected and measured.
    If any machining was needed, it was performed using Engine Building machines, including...
    ° Bores (Pistons and Mains)
    ° Crank shaft Journals (throws)
    • Crank straightness.
    Etc..
    Any Out of Round or taper were referenced according to factory specifications and corrected.
    Save money and time doing it this way? You spend more money when the engine fails you. Then the entire Long Block will need to be removed and torn down.