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ULH Piston & Connecting Rod Question

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  • ULH Piston & Connecting Rod Question

    This project got its start about 20 years ago and then got shelved. When I took the engine apart I did not mark which rod (male or female) was for front or rear cylinder. I have a recollection that it’s opposite the knuckhead and other OHV engines which would make the female rod for the front cylinder. Is this correct? The other issue is the piston placement. Both of the OEM pistons have a ‘T’ shaped mark on the crown directly above one of the piston pin holes. Does the ‘T’ go on the gear case side or sprocket side?
    IMG_0103.jpg

  • #2
    I believe the forked rod goes to the front up until 1939.

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    • #3
      Originally posted by Peter Cooke View Post
      I believe the forked rod goes to the front up until 1939.
      I think I am correct that all the forked rods that were in front also had the window cut-out for front cylinder oiling till end of 1938.

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      • #4
        A picture of the underside of the piston might show a small "fin" cast into the piston pin boss. The fin on the boss goes to the cam side.
        VPH-D

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        • #5
          Thanks VPH-D. Here's a pic of the fin on the wrist pin boss. It corresponds to the 'T' mark on top of the piston.IMG_0117 (1024x765).jpg
          Attached Files

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          • #6
            What style rings are you using? What is the baffle configuration in your cases? When H-D started supplying better oil control rings the rod positions and baffle arrangements were changed. With most modern rings the rod position should be as the later configuration with the forked rod in the rear. Original early U series engines had an oil control ring on the front piston only along with two compression rings and three compression rings on the rear with no oil control.
            Robbie Knight Amca #2736

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            • #7
              The baffles are still in place and the pistons are original standard bore. I will be using OEM rings with an oil control ring on the front cylinder. So from your information and my configuration, I should put the forked rod to the front?

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