C1 exhaust insulator screws - which is it? - NCRS Discussion Boards

C1 exhaust insulator screws - which is it?

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Keith R.
    Very Frequent User
    • August 31, 2001
    • 660

    C1 exhaust insulator screws - which is it?

    For years, the 4th edition TIM & JG said "Each insulator is attached to the bumper with two flat head slotted cadmium plated screws from the bottom. Replacement screws are often phillips head stainless steel." Now, the new 5th edition reads, " Each insulator is attached to the bumper with two Phillips flat head cadmium plated magnetic screws. Replacement screws are often slotted head stainless steel." So, which is it? slotted or Phillips?
    Keith MacRae
    NCRS #36692
    New Mexico Chapter
    1960 290HP FI
    2013 427 Convertible

    Shade tree mechanic and
    B-52 pilot extraordinaire
  • David B.
    Very Frequent User
    • March 1, 1980
    • 689

    #2
    Re: C1 exhaust insulator screws - which is it?

    If the part # is 156253 it is 1/4-20 x 3/4 cad or zinc flat head cross recess machine screw (sae 1010 - 1020 steel)

    Comment

    • Keith R.
      Very Frequent User
      • August 31, 2001
      • 660

      #3
      Re: C1 exhaust insulator screws - which is it?

      Thanks David. According to the AIM, it is indeed part # 156253 however a cross recess machine screw is not a Phillips head as it is described in the TIM & JG. It does have a photo of what could be an original car with Phillips head screws. I think I'll just go with Phillips head.CrossEdit


      A cross or double-slot screw drive has two slots, oriented perpendicular to each other, in the fastener head; a slotted screwdriver is still used to drive just one of the slots. This type is usually found in cheaply-made roofing bolts and the like, where a thread of 5 mm (0.20 in) or above has a large flattened pan head. The advantage is that they provide some measure of redundancy: should one slot be deformed in service, the second may still be used and the tool can not slip out.
      Originally posted by David Bartush (3288)
      If the part # is 156253 it is 1/4-20 x 3/4 cad or zinc flat head cross recess machine screw (sae 1010 - 1020 steel)
      Keith MacRae
      NCRS #36692
      New Mexico Chapter
      1960 290HP FI
      2013 427 Convertible

      Shade tree mechanic and
      B-52 pilot extraordinaire

      Comment

      • Bill M.
        Extremely Frequent Poster
        • April 1, 1977
        • 1386

        #4
        Re: C1 exhaust insulator screws - which is it?

        Keith:

        I definitely have the originals for my '59. They are Phillips.

        Bill

        Comment

        • Keith R.
          Very Frequent User
          • August 31, 2001
          • 660

          #5
          Re: C1 exhaust insulator screws - which is it?

          Thank you for responding Bill. That confirms things then.
          Originally posted by Bill Mashinter (1350)
          Keith:

          I definitely have the originals for my '59. They are Phillips.

          Bill
          Keith MacRae
          NCRS #36692
          New Mexico Chapter
          1960 290HP FI
          2013 427 Convertible

          Shade tree mechanic and
          B-52 pilot extraordinaire

          Comment

          • Loren L.
            Extremely Frequent Poster
            • April 30, 1976
            • 4104

            #6
            Re: C1 exhaust insulator screws - which is it?

            Does anyone else find it sad that the 58-60 Judging Team does NOT respond to these questions? Back in the '70s & '80s when I was part of THREE of these teams, DISCUSSION was the Byword, not to mention "what was the source?".

            Comment

            • David B.
              Very Frequent User
              • March 1, 1980
              • 689

              #7
              Re: C1 exhaust insulator screws - which is it?

              Originally posted by Keith Mac Rae (36692)
              Thanks David. According to the AIM, it is indeed part # 156253 however a cross recess machine screw is not a Phillips head as it is described in the TIM & JG. It does have a photo of what could be an original car with Phillips head screws. I think I'll just go with Phillips head.CrossEdit


              A cross or double-slot screw drive has two slots, oriented perpendicular to each other, in the fastener head; a slotted screwdriver is still used to drive just one of the slots. This type is usually found in cheaply-made roofing bolts and the like, where a thread of 5 mm (0.20 in) or above has a large flattened pan head. The advantage is that they provide some measure of redundancy: should one slot be deformed in service, the second may still be used and the tool can not slip out.


              Keith,
              Your description is not even close to GM Engineering Standard specifications re: Flat head cross recess machine screw.
              TRUST THE AIM! If I was computer smart I would post the print description. It's a small item so I guess it's easier to follow the crowd.

              Comment

              • Keith R.
                Very Frequent User
                • August 31, 2001
                • 660

                #8
                Re: C1 exhaust insulator screws - which is it?

                Thanks David but I was just responding your initial thread response where you said that part #156253 (depicted in the AIM) was a cross recess machine screw which is basically a double slotted screw used with a flat blade screwdriver. Rather than trust the AIM (which was not how the cars were assembled in many cases), I'd rather trust Bowtie or original cars like Bill's which actually show what was used - a flat head Phillips head zinc or cadmium screw in the insulator.
                Originally posted by David Bartush (3288)
                Keith,
                Your description is not even close to GM Engineering Standard specifications re: Flat head cross recess machine screw.
                TRUST THE AIM! If I was computer smart I would post the print description. It's a small item so I guess it's easier to follow the crowd.
                Keith MacRae
                NCRS #36692
                New Mexico Chapter
                1960 290HP FI
                2013 427 Convertible

                Shade tree mechanic and
                B-52 pilot extraordinaire

                Comment

                • Keith R.
                  Very Frequent User
                  • August 31, 2001
                  • 660

                  #9
                  Re: C1 exhaust insulator screws - which is it?

                  I hear you Loren. It would be nice if the Judging Team would be more responsive to these kinds of questions particularly when a new TIM & JG has been issued so as to work out the bugs and mistakes. There is a section on the forum where errata sheets are posted but it doesn't appear that anyone is maintaining it or posting corrections to the Judging Guides. In fairness to John Tidwell however, who helped author the 5th Edition, he did response to another mistake in this latest edition regarding the position of the seat separator lock when locked and unlocked. It is wrong in the 5th edition which caused me a lot of time, effort and minor paint damage in pulling the compartment lock and molding apart once again to determine why my lock wasn't functioning as it was described in the 5th edition. If this were posted to the Errata page, it would probably save others a lot of time and trouble with regard to their cars.
                  Originally posted by Loren Lundberg (912)
                  Does anyone else find it sad that the 58-60 Judging Team does NOT respond to these questions? Back in the '70s & '80s when I was part of THREE of these teams, DISCUSSION was the Byword, not to mention "what was the source?".
                  Keith MacRae
                  NCRS #36692
                  New Mexico Chapter
                  1960 290HP FI
                  2013 427 Convertible

                  Shade tree mechanic and
                  B-52 pilot extraordinaire

                  Comment

                  • Joe M.
                    Extremely Frequent Poster
                    • April 30, 1990
                    • 1338

                    #10
                    Re: C1 exhaust insulator screws - which is it?

                    I have judged at least six '59 and '60 Bowtie cars and all had Philips head screws. My 1960 also has Philips head screws.

                    Comment

                    • Keith R.
                      Very Frequent User
                      • August 31, 2001
                      • 660

                      #11
                      Re: C1 exhaust insulator screws - which is it?

                      Thanks very much for confirming that Joe. Looks like they got it right in the 5th edition TIM & JG. Now, I have to pull off the rear bumpers AGAIN to replace the slotted screws with Phillips head - bummer...
                      Keith MacRae
                      NCRS #36692
                      New Mexico Chapter
                      1960 290HP FI
                      2013 427 Convertible

                      Shade tree mechanic and
                      B-52 pilot extraordinaire

                      Comment

                      • David B.
                        Very Frequent User
                        • March 1, 1980
                        • 689

                        #12
                        Re: C1 exhaust insulator screws - which is it?

                        Originally posted by Joe Maulsby (17166)
                        I have judged at least six '59 and '60 Bowtie cars and all had Philips head screws. My 1960 also has Philips head screws.
                        Just to clarify what appears to be some misunderstanding #156253 described by GM as a flat head cross recess machine screw by appearance looks like what we commonly refer to as phillips head.
                        J

                        Comment

                        • Keith R.
                          Very Frequent User
                          • August 31, 2001
                          • 660

                          #13
                          Re: C1 exhaust insulator screws - which is it?

                          Yes, that seems to be the consensus David. Thanks for the clarification.
                          Originally posted by David Bartush (3288)
                          Just to clarify what appears to be some misunderstanding #156253 described by GM as a flat head cross recess machine screw by appearance looks like what we commonly refer to as phillips head.
                          J
                          Keith MacRae
                          NCRS #36692
                          New Mexico Chapter
                          1960 290HP FI
                          2013 427 Convertible

                          Shade tree mechanic and
                          B-52 pilot extraordinaire

                          Comment

                          Working...
                          Searching...Please wait.
                          An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

                          Please push the back button and reload the previous window.'
                          An unexpected error was returned: 'Your submission could not be processed because the token has expired.

                          Please push the back button and reload the previous window.'
                          An internal error has occurred and the module cannot be displayed.
                          There are no results that meet this criteria.
                          Search Result for "|||"