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  • Clutch matters...

    My car has a lightened flywheel and a V8 clutch. It came that way from an engine build from the mid-80's. The pressure plate has some chunks of steel welded on it, apparently for balancing. Note in the picture the slug of steel welded in at about the 9 o'clock position, and another welded into the hole over the spring at about the 3:30 position. I haven't looked closely (yet) to see if there is any evidence of balancing having been made to the flywheel. (Edit to add: yes, evidence of flywheel balancing is seen: large divots drilled in the outer edge.)

    Questions:
    Is this a normal way of (perhaps) balancing the entire assembly?

    How could just the pressure plate be so far out of balance to require this kind of effort?

    Is there any way a backyard mechanic (such as me) can tell/measure if a flywheel is balanced?

    Same question for a pressure plate?

    More questions:
    Is there a thread somewhere where setting the fingers is described for a V8 pressure plate? I found the tech article https://www.vintagefordforum.com/for...rs-clutch-info for a Model A pressure plate that said 11/16", but what is it for a V8 pressure plate.

    The contacts on my pressure plate look like they have either been badly worn or ground, essentially no thickness left to the heads of them. Time to replace the pressure plate?

    Any experience of the "new, not rebuilt" pressure plates offered by the vendors?

    Thanks in advance.

    Bill Lee
    V-8 Pressure plate with "balancing" slugs welded in
    Last edited by BillLee/Chandler, TX; 11-05-2018, 02:06 PM.

  • #2
    I have a new (1935 style) V8 pressure plate and clutch with good results. (mated to an F150 tranny).The package was not too expensive and was considered rather than taking chances with the prior worn/ suspect components. Be sure to check finger height alignments and the lock nuts are secure before installation because one finger was off from the other 2 by about 1/32" or so. Don't remember the finger height. Also, the pedal freeplay was a little more than stock model A. We had a shop lightly surface the already lightened flywheel and check for balance.
    Last edited by plyfor; 11-05-2018, 12:15 PM.

    Comment


    • BillLee/Chandler, TX
      Editing a comment
      Yes, it's that finger height that I need. I reassembled the old pressure plate and clutch plate and measured it at just a bit over 3/4". I suspect that's too deep since measuring a similar set-up over at Ken's this morning it was 7/16".

  • #3
    pressure plates are notoriously not in balance out of the box, they are just a stamping.
    As far as balancing or checking for balance, only a pro shop will have the highly specialized equipment to make that happen (also think $$$$)
    Are you having symptoms? Vibration? Jerky clutch engagement?
    For a Model A typically the FW and PP are balanced together (separately from the crank).
    Effort that is put into balancing a 4-cyl engine will be richly rewarded, since a 4-banger has a lot of inherent vibration/harmonics, unlike a 6-cyl, which has the least

    Comment


    • BillLee/Chandler, TX
      Editing a comment
      Thanks for the comments, Dave.

      No, no symptoms since the car isn't running (for the past year or so). But reassembling and wanting to do the best I can. When it was running, the clutch worked just fine, no chatter or jerking. As for vibration: yes there always was but no telling where from.

      I'm adding one of Ken's F150 transmissions and then encountered the leaking gas tank which as taken me the last 6-7 months to resolve.

  • #4
    You have to be careful of the new ones as some are tractor pressure plates with no weights on the ends of the fingers and some don't have adjustment bolts on the fingers.
    I would contact Fort Wayne Clutch. https://fortwayneclutch.com/

    Comment


    • #5
      Flip that pressure plate over. The fingers are held in by pins. What is securing the pins from falling out? I had a car come in with a new v-8 clutch installed that lost the clutch pedal. The lever pin fell out because they were held in by E~clips. We drilled the pins and used cottters to fix it properly. If your clutch plate has E clips fix it now
      2 1930 Tudors

      Henry Ford said
      "It's all nuts and bolts"


      Mitch's Auto Service ctr

      Comment


      • #6
        Mitch, extremely good point

        If you are going thru all this right now, if it were me, I'd yank the FW, check the PP as per Mitch, and haul them both to the machine shop for a good balance. It will be the best money you could spend. Be sure to use paint to index the two together, and some decent grade 8 bolts, or ARP bolts, along with blue loctite for the PP.

        When removing or installing the FW an old trick is to use some longer bolts that the heads are cut off, to use as dowel pins, and you won't have to wrestle with the FW as much.
        Last edited by tbirdtbird; 11-05-2018, 07:06 PM.

        Comment


        • Mitch
          Mitch commented
          Editing a comment
          Dave I know you remember that job...

          Hint:: Fork lift extensions

        • tbirdtbird
          tbirdtbird commented
          Editing a comment
          I sure do. Wasn't it Cape Codder?

          I liked the extensions, and did not know they existed.
          I kinda made my own extensions but was too chicken to use them. It would be better to have the actual product.
          Last edited by tbirdtbird; 11-05-2018, 07:05 PM.

        • BillLee/Chandler, TX
          Editing a comment
          The stash of old head studs worked wonderfully well today! :-)

        • Mitch
          Mitch commented
          Editing a comment
          yes it was the Cape's buddy Paul

      • #7
        If you still have that pic, it would make a nice addition here.....

        Comment


        • #8
          On my recent rebuild, I felled to have the flywheel resurfaced and balanced. I have seen flywheels drilled and stuff (like nuts and washers) welded on them to get them balanced. The vibration starts at 38 mph and then actually smooths out above 40. I am determined to find somebody who lives in the deep south to balance out my flywheel (purchased from a buddy just yesterday) along with one of my pressure plates as a unit this winter. Let the search begin.

          Comment


          • BillLee/Chandler, TX
            Editing a comment
            What part of the deep south are you looking for?

            Ken Parker has directed me to two different places here within 20 miles or so of Tyler, TX. When my new PP gets here, it and the flywheel are off to be balanced.

          • tbirdtbird
            tbirdtbird commented
            Editing a comment
            any machine shop should have this capability

          • 40B1930
            40B1930 commented
            Editing a comment
            When I lived in Dothan, AL and Paris, TN, I never had any problems finding well experienced mechanics who lived, ate and breathed thinking about a really slick (or better) way to do a job.
            I discovered the common thread was they loved their cars. Nascar racing, NHRA drag racing, drag racing at their local track, and just hanging out in the car repair and body shops.
            Their is absolutely some terrific qualified mechanics across America (stated to please those non believers of my point) however, the demographics/population/sheer numbers of them in the South is a fact.
            The shops that were around with the equipment when I was a kid are long gone. Finding someone who routinely pours babbit and other jobs where I live - all long gone. The one guy I was sent to who has a machine to surface a flywheel told me he hadn't used it in years and didnt want to drag it out.

            In closing, I seriously do not mind paying to have something done, I just require that who ever does the work has done it most of there life! And we dont have anyone around here that meets my very basic premise.

            Okay, let the civil debate begin!

        • #9
          The combination of all your parts can be statically balanced by using an old style tire bubble balancer. You can't use the bubble, but if you place your cell phone across the center with the Clinometer app turned on, it will tell you where to add the weight. Another use for that great FREE app!!
          "We do not stop playing because we grow old;
          We grow old because we stop playing ...
          NEVER Be The First To Get Old!" Pilfered from the MAFC SA Newsletter

          I JUST CAN'T FIX STUPID!!

          Comment


          • tbirdtbird
            tbirdtbird commented
            Editing a comment
            Wiz, would you not prefer a dynamic balance? A bubble balance may be OK for a wheel, but the FW is turning 3.78 times faster

          • DaWizard
            DaWizard commented
            Editing a comment
            Sure, but when you must, a balance is a balance.

          • Mitch
            Mitch commented
            Editing a comment
            Sorry but I'm not in on this tire bubble balancing a flywheel deal.

        • #10
          While waiting for my new pressure plate to arrive .....

          I measured the "wobble" in the flywheel, about .005" edge-edge.

          Trying to understand, I pulled it off and measured the flange on the end of the crankshaft. See the picture. IMG_20181106_091629A.jpg I measured at the outer edge, again just inside the bolt holes and then at the inner edge just adjacent to the pilot bearing hole. The numbers are thousandths.

          Questions ....

          What is the tolerance for the crank flange?

          How can a flange like this become tapered from the center out only on one side?

          The measured "wobble" on the flywheel coincides with the strange slope seen here.

          What will be the effect if I do nothing but bolt it back together? Short of totally disassembling the engine and sending the crank off to a machine shop, can anything be done?

          TIA

          Regards,

          Bill Lee


          Attached Files

          Comment


          • #11
            I dont like the way the weights were added in that first photo. weight should be added as near the outer circumference as possible. Welding a slug in the hole where the spring sits is a bad idea. I had one balanced that way, and when I installed it, the slug prevented the clutch plate from retracting, and I had to take the whole thing apart again and have it done correctly.
            Bill
            http://www.brauchauto.com/
            Eastern Connecticut

            Comment


          • #12
            Don't forget to check the pins. What did your old pressure plate have?
            2 1930 Tudors

            Henry Ford said
            "It's all nuts and bolts"


            Mitch's Auto Service ctr

            Comment


            • BillLee/Chandler, TX
              Editing a comment
              As best as i can tell, the old plate had E-pins. (Kind of hard to see with the grime in there.)

              Can you explain how to switch to cotters? That sure looks like a very small area to try to drill a hole.

            • Mitch
              Mitch commented
              Editing a comment
              Yikes E clips don't ever use one with them. If your buying a new pressure plate get one with cotters holding the pins in. Otherwise drill a tiny hole into the pin while its still installed or pull the pin out and drill it. A very small cotter pin is all that is needed

          • #13
            Not sure I understand what you measured.
            And how.
            You used a dial indicator with a magnetic base?
            The .005" is runout ? or lack of concentricity ?
            Runout is gonna be harder to measure because of the crank thrust
            Last edited by tbirdtbird; 11-06-2018, 07:29 PM.

            Comment


            • #14
              I measured the face of the flywheel at the outer edge of the contact area. I call that measurement "wobble" as opposed to measuring the edge of the flywheel for being out-of-round, (i.e. concentricity).

              I used a magnetic base and a dial indicator, engine pointed down to keep the crankshaft solid against the thrust bearing.

              Comment


              • #15
                OK, assuming no burs or gouges, then take the same measurements on the crank flange...
                ie
                concentricity and runout

                I rather doubt it is the flange at fault, but rather the FW

                When you say 'contact area' you mean where the disc contacts I presume

                I cannot make out the numbers written on the flange.

                Summary, we need 2 sets of measurements, one set is concentricity and runout with FW mounted, and torqued up,
                the other with the FW off thus concentricity and runout of flange

                Comment


                • #16
                  Originally posted by tbirdtbird View Post
                  OK, assuming no burs or gouges, then take the same measurements on the crank flange...
                  ie
                  concentricity and runout
                  This picture is the "runout" of the crank flange.
                  IMG_20181106_091629A.jpg
                  If you click on the image you should get a full-size view. You will see that there are three numbers written at each location where I measured the runout. For three of the locations, those numbers were all zero, but at the fourth, they were 0, -2, and -4 (thousandths) measured from the center to the outer edge.

                  I do not have the concentricity measurements for the flange nor the flywheel, and it will be this weekend before I can get back to it.

                  Originally posted by tbirdtbird View Post
                  I rather doubt it is the flange at fault, but rather the FW

                  When you say 'contact area' you mean where the disc contacts I presume
                  Yes.

                  Originally posted by tbirdtbird View Post
                  I cannot make out the numbers written on the flange.

                  Summary, we need 2 sets of measurements, one set is concentricity and runout with FW mounted, and torqued up,
                  the other with the FW off thus concentricity and runout of flange
                  Will get in a few days.

                  Comment


                  • tbirdtbird
                    tbirdtbird commented
                    Editing a comment
                    OK, thanks for that, the pic is making a little more sense now. But how can the runout at the same location be either 0, -2, and -4.
                    Unless these are deviations radially from the center?

                    I would think the outer perimeter would be the most important number.
                    If that is the case then someone dropped the crank on the floor.

                    A most interesting question would be what prompted you to take all these measurements
                    Last edited by tbirdtbird; 11-07-2018, 11:09 AM.

                  • BillLee/Chandler, TX
                    Editing a comment
                    Yes, those are runout when measured at the edge of the pilot bearing hole, (.000"), just inside the bolt holes (-.002"), ad then at the outer edge of the flange (-.004").

                  • BillLee/Chandler, TX
                    Editing a comment
                    I suspect the crank was dropped or hit with a hammer or something in its 90 year history. If you look closely at the picture you can see a couple of spots that are depressed, like where it might have been hit.

                  • BillLee/Chandler, TX
                    Editing a comment
                    Prompted: when I measured the runout of the flywheel at the edge of the disk contact area, I found .005" from one edge to the other. All of the measurements of the crankshaft flange are simply to try and understand where it's coming from.

                • #17
                  Bill, what I would do is clean the crank good, install the flywheel and see what the runout on the flywheel is, or if there is any at all. I can't give you a specific number as a base, but if II had runout more than about .010 at the clutch surface I would probably do something about it.

                  But that is just me.
                  "We do not stop playing because we grow old;
                  We grow old because we stop playing ...
                  NEVER Be The First To Get Old!" Pilfered from the MAFC SA Newsletter

                  I JUST CAN'T FIX STUPID!!

                  Comment


                  • #18
                    Calling George Miller, interested in hearing your thoughts on all this

                    Comment


                    • #19
                      well that is a lot to think about. are you turning the crank to measure the flange? Run out on the OD of the flange is .0005 I would not want any more than .0005 on flange run out also. But that is hard to measure. The crank can move flange in and out when you turn the engine. best way is to turn the engine with the front of the engine pointing down.

                      When it comes to engines every thing should be put back in the same place it was before. The pressure plate should be marked and put back like it was before. If they were balanced together and you do not put them back the way they were it is going vibrate. Engines look simple, but the A is hard to get right, especially after 90 years of people working on them and not always doing the job right. I see the cranks off the original center line, not square with the top of block, bearings not bored in line with each other. another thing that you see all the time is the cylinders are bored off there original location. That happens when some locates the boring bar to take the least amount out of the cylinder to clean up the bore,not good.

                      Comment


                      • BillLee/Chandler, TX
                        Editing a comment
                        All measurements were made with the nose of the engine pointing down to keep the crank tight to the thrust bearing.

                        Do really mean .0005 (i.e. a half thousandths)?

                      • George Miller
                        George Miller commented
                        Editing a comment
                        Yes I do Bill .0005 is the speck on run out, you have 63 lbs that will be running out, that will cause a lot of shaking. That is a normal run out speck.

                    • #20
                      Got my new pressure plate today. The release lever fulcrum pin is held neither by an E-clip NOR a cotterpin! Instead, the end of the pin is split and then spread after installation. IMG_20181108_184453A.jpg

                      Anybody have any concerns about this method? I don't think the pin is going to come out!

                      Comment


                      • Mitch
                        Mitch commented
                        Editing a comment
                        Beautiful... As long as it's not an E-clip

                      • tbirdtbird
                        tbirdtbird commented
                        Editing a comment
                        I can't really see what they did from the pic

                    • #21
                      What is missing here are the symptoms which triggered you to take all these measurements.
                      I seriously do not think the engine builders here can adequately counsel you under these circumstances.
                      There was a very vague mention of vibration at some point, but if that is the issue, there were no details provided, such as, at what speed, hot or cold, idle or under load, using the clutch or not, etc etc.

                      I feel we could be way more helpful.

                      As far as generic causes of vibration, the list is as long as your arm.
                      1. Pistons not balanced to each other. Pistons out of the box are notorious for being at varying weights. Egge pistons, for example, are famous for being off by as much as 30 g
                      2. rods not balanced to each other, which includes using equipment that can weigh the big end separately from the small end
                      3. improperly balanced crank
                      4. For an A, the FW and PP are typically balanced together, and not when bolted to the crank
                      5. too much advance. Timing that is too advanced, but not so far as to cause ping, will trigger vibration, since the engine is fighting itself
                      6. unequal compression amongst cylinders
                      etc

                      As has been stated, a four banger engine is inherently unstable, and needs all the help you can give it in terms of balancing. The physics of the rotating mass will not be denied. Look up harmonics for starters. Harmonics are what brought down the Tacoma Narrows bridge in 1940. (also known as Galloping Gertie)
                      https://www.youtube.com/watch?v=j-zczJXSxnw
                      This incredible video is shown in every physics and engineering class

                      A 6-cylinder motor, or a multiple of 6, is inherently the most stable configuration.
                      There are many aspiring 'engine builders' out there who are guilty of just grabbing the pistons out of the box, shoving them in the holes, and calling it good.

                      I raise all these points with the hope of increasing awareness on the part of the forum members.
                      Even if you never build an engine, you will be able to talk intelligently to your engine builder, and do not let him talk you out of any of these important points, instead, go elsewhere.

                      The lifespan of your engine bearings depends on a good balance
                      Last edited by tbirdtbird; 11-09-2018, 09:00 AM.

                      Comment


                      • #22
                        Originally posted by BillLee/Chandler, TX View Post
                        This picture is the "runout" of the crank flange.
                        IMG_20181106_091629A.jpg
                        If you click on the image you should get a full-size view. You will see that there are three numbers written at each location where I measured the runout. For three of the locations, those numbers were all zero, but at the fourth, they were 0, -2, and -4 (thousandths) measured from the center to the outer edge.

                        I do not have the concentricity measurements for the flange nor the flywheel, and it will be this weekend before I can get back to it.


                        Yes.



                        Will get in a few days.
                        If you have .004 there at the face it is going to be running out a lot on the outer edge of the flywheel. that will cause a viberation.

                        Comment


                        • George Miller
                          George Miller commented
                          Editing a comment
                          I see what you are saying now. Looks like a bent flange. I would try bolting the flywheel on and see what kind of run out on the face and OD of the flywheel.

                      • #23
                        Bill, you gave an explanation of what you were up to as a comment and I did not see it until today, sorry

                        Comment


                        • #24
                          I made the decision over the weekend to get it all right! Today I pulled the crankshaft out of the engine. Tomorrow, it, the flywheel and the new pressure plate will be off to Charlie Ray's shop. Will have him true up the crank flange, check the flywheel and true if necessary and then balance it all.

                          Oh, I could have just bolted it back together and it would have been "all right", but I'd be thinking about it forever. Best to just get it done properly now.

                          Comment


                          • DaWizard
                            DaWizard commented
                            Editing a comment
                            X10

                            If you don't do it right the first time, you WILL do it right the second time!

                          • Mitch
                            Mitch commented
                            Editing a comment
                            Keep us posted on the findings.. thanks

                        • #25
                          Did Charlie make any comments when you told him what you needed done, and why???

                          Comment

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