No announcement yet.

motor balancing attempt with pics

  • Filter
  • Time
  • Show
Clear All
new posts

  • motor balancing attempt with pics

    First of all this was not my attempt
    What can you knowledgable Model A guys tell me about this attempt to balance this A motor ?
    here are the facts:
    - The motor has only about 5 hours on it after rebuild and balanced.
    - no matter the positioning of the flywheel in relation to the pressure plate it would shake the fillings out of your teeth.
    - using a fairly accurate kitchen scale, which only reads in pounds and kilograms, the pistons with connecting rods attached
    were weighed with the following results #1 - 2.75 lbs., #2 - 2.5 lbs, #3-3.25 lbs, #4-2.5 lbs. lead had been poured into the rod fluting on # 1 and 3
    - you will see the added weights on the crankshaft which had some holes drilled into them in various locations after welding in place.
    - someone had mentioned the pistons and rods should have started out weighing within one gram of each other to get a balanced motor.
    - someone else mentioned the builder was possibly using bob wires to hang the pistons and rods onto the weight added crankshaft
    to balance the motor.
    - I have never heard that or any other method of motor balancing so here is the chance for you guru's to give your input.
    - The front babbitt was in real good shape, the rear babbitt looked good except for the thrust area which was not done properly as it had way too much play
    - The crank journals looked real good except it hung up a bit when rotating freely and started binding around 270 deg. until 360 deg. then it freed up
    again until it reached the 270 deg. area. either it has a bent crank or its out of align bore.
    - Is this motor worth saving and if so what would have to be done to fix it. ?
    - Can anyone describe in detail in laymens terms the proper procedure in balancing the rods/pistons/crank

    You do not have permission to view this gallery.
    This gallery has 2 photos.

  • #2
    FWIW:: We had a motor in that would vibrate the hell out of ya, a classic imbalance type feel. . We removed the clutch from the flywheel and started it, the vibration completely went away.
    This is not really answering your question but i thought it was mention able
    3~ Tudor's & 1~ Coupe
    Henry Ford said,
    "It's all nuts and bolts"
    "Start by doing what's necessary; then do what's possible; and suddenly you are doing the impossible."

    Mitch's Auto Service ctr


    • #3
      the rod/piston assemblies are so far SHOULD vibrate.
      Pistons are balanced separately from rods, using very sensitive digital machinists scales.
      Cranks are balanced using very special highly sophisticated equipment. The crank is usually balanced separately; the flywheel and pressure plate as a unit, then mark the PP and FW to index them in case they are taken apart


      • #4
        See post 11 in this thread for how it should be done



        • Mitch
          Mitch commented
          Editing a comment
          Many of us here are BANNED incl'd me from seeing the link you posted.

      • #5
        Originally posted by Mitch View Post
        Many of us here are BANNED incl'd me from seeing the link you posted.
        It's a posting from J&M machine shop showing the special tools needed to balance the crank, flywheel and pressure plate, pistons, and rods.


        • #6
          Here's the pics
          Attached Files


          Related Topics


          • Fixitphil
            Connecting Rod Balancing
            by Fixitphil
            Again I'm new at this game and haven't seen much, but this situation does not seem right. Give me your input please.
            I'm getting a new engine so I tore the old engine down to see what it was like.
            1. I found one of the rods had a 1.5 in long weight welded inside the web. Nothing on the other side.
            2. Second rod had a 3" weight welded to each side of the rod.
            3. Third...
            You do not have permission to view this gallery.
            This gallery has 1 photos.
            08-12-2018, 12:03 PM
          • Chevmn56
            Motor Questions
            by Chevmn56
            I was cleaning the block today getting ready to put the pan back on , while i was under Clyde i started to look around at the bottom side of the motor, im going to show my ignorance again but i will ask.....i noticed the crank has had holes drilled in the end of the lobs (counter weight) and the lobs look as though they have been welded on, i thought these motors where not balanced????? and i thought...
            02-05-2018, 09:54 PM
          • Greynomad
            Reboring a motor with sleeves
            by Greynomad
            I have a motor that was tarted up by a not very skilled workshop over there before I bought the car. After a few miles, I find that the wrist pins are loose in 3 cylinders, the pistons have been expanded and a few other things done. The only way to fix this motor properly is to rebore it and treat it to a new set of pistons, rings etc but it has been sleeved at some time and then taken out to 0.060"...
            09-12-2019, 12:27 AM
          • Dennis
            Burlington crankshaft and float-a-motor mounts
            by Dennis
            I was reading Burlington's website about recommendations and noticed they recommend not using float a motor mounts. Anybody have experience with a Burlington and would like to comment? I realize this is a suggestion and not required. Also I notice the kit made to install a 32 and up trans requires float a motor mounts, so it looks like you don't have a choice in that circumstance.

            02-02-2018, 07:23 AM
          • Jm29henry
            Motor Munster greenfield village
            by Jm29henry
            Has any one heard how motor Munster is going with the new rules?
            06-17-2017, 07:37 PM
          • gpowers
            Complete motor and transmission
            by gpowers
            I know this is probably another dumb question from a first time Model Aer but I was thinking it might be worthwhile to purchase an extra motor or transmission for spare parts if I had the opportunity. I have come across a complete motor and transmission for $300. The guy doesn't know what it came out of but says it turns over by hand. The only thing missing from the motor that I can tell from the...
            02-14-2019, 05:58 PM
          • tbirdtbird
            Engine rebuilding
            by tbirdtbird
            Many Model A owners will need their engine overhauled at some point. There are great many questions that come up when this occurs. We strongly encourage owners to do careful research, as there seems to be a lot of shops that claim they know engine building, but few that really do. Questions such as, babbitt or inserts, ring gaps, piston-to-cyl wall clearance, piston choices, camshaft choices, proper...
            04-30-2017, 07:39 PM
          • George Miller
            What is the advantage of putting sleeves in and going back to standard.
            by George Miller
            I under stand if you can not go bigger. But it sounds like some put sleeves in even if they have room to bore more.
            01-19-2018, 11:33 AM
          • Jwmckenzie
            Engine Balance - What was done originally from factory
            by Jwmckenzie
            In a recent thread discussing various options for building a short/long block, I began wondering how these engines were originally balanced.

            Certainly today when having a engine built I would spare no expense to make sure all the moving parts from front pulley to pressure plate were balanced. The rotating engine parts for '29 pickup were balance as a unit. I don't remember for sure...
            02-10-2019, 02:55 PM
          • BillEbob
            Follow-up to: Oh No it’s happened to me!
            by BillEbob
            We were finally able to get to the Vicky this past Saturday. As my friend said, “if you’re going to have major engine problems, this is the kind to have!”

            After removing the pan, we saw “a lot” of babbitt in the splash pan. Further investigation showed that #1 piston bearing was coming apart.

            The good news is that it is ONLY that one! The others are all fine.
            11-12-2018, 09:09 PM