Do you have rods in your head? I do.

Slant 6 Engines

  1. cruiser

    cruiser Well-Known Member

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    Hi All: I was changing the thermostat in my 1974 slant six yesterday, and something interesting caught my eye. As I peered into the cylinder head through the thermostat opening, I saw two rods - one straight and one curving - in the head. They appeared to be about 1/4" in diameter. They looked like they shouldn't have been there, so I tried pulling them out through the thermostat hole but they wouldn't budge. So I just left them there and finished the stat installation job. The engine runs perfectly with these rods there. Then I recalled an article some years back about these rods somehow being part of the head casting process, and are sometimes (or usually) just left there after the heads are made. So what gives? Why would the factory leave this waste material there? How is it that it doesn't affect the performance of the head? Perhaps it's just me, but it bugs me that these things are in my engine, and I want them out. Your thoughts?
     
  2. RustyRatRod

    RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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    Pretty common in slant sixes and I've seen some in V8s too. They were part of the casting process. Sometimes you can pull them out, sometimes not. They don't hurt a thing.
     
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    • Killer6

      Killer6 Well-Known Member

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      There are long stretches of core without support, they laid hard wire in those sections when they had the patterns 1/2 full(approx) so they wouldn't drop out or collapse, it is annoying to see them in there. Mass production, water navigates around it fine, they don't care. I've always wondered if some caused mystery noises at certain rpms, just ending up in the wrong shape/position, coolant flow causing them to "flutter" against the water jacket.
       
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      • RustyRatRod

        RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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        That's an interesting theory and one I had not thought of before.
         
      • RAT ROD AL

        RAT ROD AL I know just enough to be dangerous FABO Gold Member

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        Made me think of this guy ! And you thought you had problems. Lol
        20211121_074758.jpg
         
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        • Tooljunkie

          Tooljunkie King of cobble/master of the broken bolt FABO Gold Member

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          I know a guy that survived a shifter through his skull. He was the only one concious after the crash and flagged a car down for help. It when from bridge of his nose to base of his skull. He’s been doing a lecture at drivers ed classes for many years.
           
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          • Charrlie_S

            Charrlie_S Well-Known Member

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            You mean they still have them? Wouldn't know it, by the way people drive
             
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            • Dana67Dart

              Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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              When I was in HS (late 70s) we had drivers Ed as a class. Red Asphalt anyone! Those were the days!
               
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              • Garrett Ellison

                Garrett Ellison Amateur driver on public roadway, do not imitate.. FABO Gold Member

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                Not For The Squeamish!
                 
              • Mike69cuda

                Mike69cuda 66 is the new 17 FABO Gold Member

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                Mostly nuts, according to my wife……
                 
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                • kchumeam

                  kchumeam Member

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                  I have too
                   
                • Dana67Dart

                  Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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                  I would love to see a photo of the rods in the /6 head, it's a first for me.
                   
                • RustyRatRod

                  RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                  Red Asphalt and Blood on the Highway. Remember them well.
                   
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                  • Dartswinger70

                    Dartswinger70 I been North I been East to the California beach

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                    I thought "Red Asphalt" was the drivers ed class teachers name...:)

                    blood on the highway sounds like a horror movie about a psychopathic truck driver...:)
                     
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                    • cruiser

                      cruiser Well-Known Member

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                      Here you go. Not a very good shot, but you can see the rods all the way in the back.

                      IMG_2594.jpg
                       
                    • Dana67Dart

                      Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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                      IMG_2594~2.jpg

                      That's crazy! Well I always say you /6ers are a bit off kilter!:poke::rolleyes:
                       
                    • pishta

                      pishta I know I'm right....

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                      You can pull them out if you have a long set of needle.nose pliers. They are like heavy coat hangers. I doubt they will vibrate in water enough to make any noise above the 12 solid lifters, timing chain and a water pump.....
                       
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                      • volaredon

                        volaredon Well-Known Member

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                        I have 4 /6 heads here. I pulled rods like that out of 3 of them, haven't checked the 4th that closely/ since it was a "fresh from a machine shop 30 years ago, still wrapped in plastic", find.....
                         
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                        • Krooser

                          Krooser Building Chinese Free Engines since 1959...

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                          Mechanized Death was our drivers ed movie.....

                           
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                          • cruiser

                            cruiser Well-Known Member

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                            Hi Pishta: I tried to pull one of them out, but it wouldn't budge. I had the head in the machine shop for rework two years ago. Should have done it then, but I didn't notice the rods inside there. Had I noticed, I'd definitely have had them extract the rods. It was impossible for me to move them even the slightest bit. Perhaps they're rusted into the iron head casting. This whole thing puzzles me. Why would the foundry leave this foreign matter in the head back in the day? All they needed to do was to yank them out and then send the head to its engine. Like leaving a socket wrench in the floor of the car as it's being built along the assembly line. It doesn't belong there. Shows how anal I am, I guess.
                             
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                            • pishta

                              pishta I know I'm right....

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                              The spars were there to support the sand mold cores. They poured Iron around the cores and the spars so your are probably still captive in the iron. They vibrate the sand cores loose and they fall out but the spars stay in there. If they are free to pull out, they probably rusted themselves free from the iron walls. Mine came out as if they were stuffed in there. My block and head was pretty rusty inside too, about a cup of sediment came out after the core plugs were removed and the drain was cleared.
                               
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                              • Garrett Ellison

                                Garrett Ellison Amateur driver on public roadway, do not imitate.. FABO Gold Member

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                                If there still attached, I'd just leave them alone. I've never had a problem from too much iron in something, but sure have had problems from not enough! The ones I've seen blended into the head so well that I thought they were an intentional vent in the sand cores.
                                 
                              • Swinger 340

                                Swinger 340 Well-Known Member

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                                Possible the "RODS" were put there on purpose, to slow the water flow for added cooling.
                                 
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                                • Dale Davies

                                  Dale Davies Well-Known Member

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                                  They are put in the casting molds to hold pieces in place where a void needs to be after casting is complete and the sand is removed. Core shift happens when some part is not held in the correct position.
                                  Those bits of wire are frequently like welding rod. Eventually many corrode into oblivion.
                                   
                                • Dale Davies

                                  Dale Davies Well-Known Member

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                                  Many sand castings have them. Most are not visible.
                                   
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