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  • Engine: Stuck valve

    A local Chapter member has just recently finished a complete restoration on his 1952 2R5 pickup (170 engine) It probably has less than 200 miles on the rebuilt engine. He asked me my opinion on why it has developed a miss. He has done a compression test and one cylinder had no compression. I suggested he pull the head and have a look. He did and low and behold one valve was stuck open. He managed to tap the valve down some and proceeded to turn the engine over by hand. It will turn over only far enough until the lobe of the cam tries to push the valve up and the engine now cannot be turned over any farther. I am not a guy that knows much about flat head 6 cylinder engines but is this not an indication of a possible bent valve or a tight guide? It ran fine for a couple of hundred miles, what happened here? Open for suggestions.
    Last edited by 41 Frank; 09-14-2021, 11:00 AM.
    Frank van Doorn
    Omaha, Ne.
    1962 GT Hawk 289 4 speed
    1941 Champion streetrod, R-2 Powered, GM 200-4R trans.
    1952 V-8 232 Commander State "Starliner" hardtop OD

  • #2
    How many years ago did it run " fine for a couple of hundred miles" ??

    Comment


    • #3
      I believe that you are on target with bent valve - just replace it.
      Gary L.
      Wappinger, NY

      SDC member since 1968
      Studebaker enthusiast much longer

      Comment


      • #4
        Originally posted by Dan Timberlake View Post
        How many years ago did it run " fine for a couple of hundred miles" ??
        First started this summer after fresh rebuilt and driven the 200 miles.
        Frank van Doorn
        Omaha, Ne.
        1962 GT Hawk 289 4 speed
        1941 Champion streetrod, R-2 Powered, GM 200-4R trans.
        1952 V-8 232 Commander State "Starliner" hardtop OD

        Comment


        • #5
          Most likely a tight guide. Almost impossible for a fresh rebuild to bend a valve after startup. Is the stuck valve intake or exhaust?

          While the head is off, squirt solvent down the valve guide. Rock the engine each direction by hand and the valve should free up. It's about 50/50 whether it will hang up again. Easy enough to remove the valve and open it a touch with a reamer.

          jack vines
          PackardV8

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          • #6
            Originally posted by PackardV8 View Post
            Most likely a tight guide. Almost impossible for a fresh rebuild to bend a valve after startup. Is the stuck valve intake or exhaust?

            While the head is off, squirt solvent down the valve guide. Rock the engine each direction by hand and the valve should free up. It's about 50/50 whether it will hang up again. Easy enough to remove the valve and open it a touch with a reamer.

            jack vines
            It is an exhaust valve Jack and I will give him your suggestions. I do have a set of reamers if that is what it takes.

            Thanks!
            Frank van Doorn
            Omaha, Ne.
            1962 GT Hawk 289 4 speed
            1941 Champion streetrod, R-2 Powered, GM 200-4R trans.
            1952 V-8 232 Commander State "Starliner" hardtop OD

            Comment


            • #7
              I had a similar problem on a tractor (valve in head) that turned out to be a broken valve spring. The broken end turned inside the spring and it was hard to see the problem until we took it apart.

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              • #8
                Originally posted by Squatch View Post
                I had a similar problem on a tractor (valve in head) that turned out to be a broken valve spring. The broken end turned inside the spring and it was hard to see the problem until we took it apart.
                In the case of a broken spring, the valve would be able to be pushed open after it was pushed closed - not the case here (see post #1).
                Gary L.
                Wappinger, NY

                SDC member since 1968
                Studebaker enthusiast much longer

                Comment


                • #9
                  Nope, and we bent a pushrod by being impatient and not figuring out the real problem before we turned it over. The end caught between the valve guide and retainer.

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