Roller rocker centered on the valve stem

Engine, Trans & Driveline

  1. Paul_G

    Paul_G Well-Known Member

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    Take a look at these please. I think the roller tip is not centered on the valve stem correctly. How can I get the tip to ride in the center? Trick Flow PP240 heads with Harland Sharp rockers made for Eddy and TF heads.

    I have the push rod checker tool at 8.785" which leaves about 1 thread exposed below the rocker arm. Right at HS spec.

    20200212-150614.jpg
    [​IMG]
    20200212-150947.jpg
     
  2. diesel_lv

    diesel_lv Well-Known Member

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    It's been a few months since I did mine. I believe it was shimming under the shaft that got mine centered. But once centered, you will have to check pushrod length again.
     
  3. dvw

    dvw Well-Known Member

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    Centered doesn't matter. You're looking for the smallest sweep. You can use a kit from B-3 to get it as close as possible. To be honest it doesn't look that bad. Way to many get all worried about it. Personally, I'd run it.
    Doug
     
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    • 66Satellite47

      66Satellite47 FBBO Gold Member FBBO Gold Member

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      Looks pretty good to me. Maybe a small shim under the shaft. The sweep looks about as good as can be expected. But I'm not a professional builder.
       
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      • Paul_G

        Paul_G Well-Known Member

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        I am going to take a side shot of the roller on the valve tip today. I want to see where the roller is at max lift.
         
      • threewood

        threewood FBBO Gold Member FBBO Gold Member

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        • wyrmrider

          wyrmrider Well-Known Member

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          let's see the closed and max lift and mid lift
          sweep is not as bad as most and you are centered close enough
          your stars align
          what dvw said
          The TF heads evidently have the shafts moved up and away from iron head locations already
          I would ask B3 what his experiences with those heads and rockers are
          but I'd run them
          (never heard me say that before)
           
        • Paul_G

          Paul_G Well-Known Member

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          Pics of the roller from the side. My push rod tool is at 8.875" which is an off the shelf length. I have it set at 1 turn preload. The roller lifters were soaked over night before install, but that was a couple of months ago.

          This is on the cam base circle
          20200213-102212.jpg

          This is at max lift
          20200213-102304.jpg
           
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          • steve340

            steve340 Well-Known Member

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            That rocker shaft needs to go down not up with shims. The only way to do that is machine the pedestals down.
            Given the marked valve tip shown in your first pics - the sweep is pretty narrow and no where near the edge of the valve.
            I would run it as is.
            I assume you have a solid cam?
             
            Last edited: Feb 13, 2020
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            • Paul_G

              Paul_G Well-Known Member

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              Hydraulic roller
               
            • steve340

              steve340 Well-Known Member

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              Then the mark you made is wrong unless you somehow allowed for the collapse of the roller lifter.
              For a hydraulic cam you should use a light checking spring.
              I would say the mark will be a lot further out than you think.
               
            • Paul_G

              Paul_G Well-Known Member

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              Would bottoming out the lifter with the push rod check tool work? Then recheck. Or bad idea?
               
            • 66Satellite47

              66Satellite47 FBBO Gold Member FBBO Gold Member

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              Paul G, I mistook your "mark" for an actual wear pattern & presumed a solid cam. Forget my comments.
               
            • Paul_G

              Paul_G Well-Known Member

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              I called Harand Sharp and explained my issue, sent him a bunch of pictures. He said that these rockers were made specially for my combo, others have used them with the TF heads and said they are spot on. Waiting to hear back from him.

              I am probably doing something wrong.
               
            • steve340

              steve340 Well-Known Member

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              I have used Harland Sharp and Comp Cams(who are Harland Sharp I believe)and their geometry is not good. The best by far is the Hughes setup.
              No you cannot bottom out the lifter because that is not were it will run when the oil pressure pumps it up.
              It is pretty simple. Substitute a pair of light check springs on one cylinder. Set the valve lash at zero and look for mid valve tip or close at mid lift on the cam. Ensure the lifter is not compressed by the checking spring.
              You cannot mark it the way you have previously done it you will need to eyeball the valve tip.
               
            • wyrmrider

              wyrmrider Well-Known Member

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              put a machinest rule through the center of the roller and the fulcrum- just but the bottom of the rule against the center of the shaft and the bottom through the center of the rocker
              what do you see with your eyeballs at closed, open, half
              pics please
              I want that rule parallel with the top of the retainer at half lift
              what do you see
               
            • Paul_G

              Paul_G Well-Known Member

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              Like many things during this engine build, doing the research, I have learned more about valve train geometry than I wanted to know. I need to get a valve spring compressor and some checker springs to do it right.
               
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              • wyrmrider

                wyrmrider Well-Known Member

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                good on you paul
                we're here to help
                 
              • Paul_G

                Paul_G Well-Known Member

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                Maybe this guy explained it well. Not a Mopar shaft mount, but I get the idea.

                 
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                • steve340

                  steve340 Well-Known Member

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                  I have been doing engines since I was an apprentice and had never heard of rocker geometry until I purchased an engine blueprinting book about 25 or so years ago.
                  At least you knew to check it.
                  That video from Straub is pretty good but the old way of centre of valve at half cam lift still works fine. I have done quite a few engines over the years and your eye is pretty good.
                  The sweep of the rocker over the valve tip is fairly important. If your sweep on a Mopar is around or less than 1 mm or 0.040 thou you are doing pretty good. A little bit off centre will cause no issues. With the shaft mounted rockers you cannot alter the rocker geometry with push rod length as described in the video.
                  To alter the geometry on a Mopar you need to move the rocker shaft up or down. It would be nice to move it in or away from the valve also but as we know that cannot happen with the cast in pedestals. A Mopar rocker is pretty short and that is some of the trouble.
                  To optimise the push rod length put a DTI on the spring retainer and play with the push rod length until you get the most valve lift.
                  Have the adjuster screw far enough out of the rocker to ensure it is low enough for oil to spray in to the push rod cup. If your push rod is too long I believe you can starve the rocker end of the push rod a bit.
                  I modify the Harland Sharp, the push rod oiling hole is huge and no oil goes to the rocker tip. I only buy the Hughes ones now.

                  I will
                   
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