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  • #31
    Originally posted by SuperBuickGuy View Post
    cool, I'll be around tomorrow if you want to come practice - otherwise, my next availability is next Sunday.
    Unfortunately, I don't have the material yet, if you know of someone in the area who has 3/8 304 stainless flange material, on the shelf in less than giant quantities, I'd love to know! I'll let you know as soon as I have everything together!

    I got started on the new set of turbo manifolds, or at least the parts that I can without the flanges in hand.

    the forward most ports will use 90* bends. and the downstream ports will use 45*, contoured to the pipe. the main log is tapered from the 1.5" 90*, to a 2" discharge at the end. I plan to use a V-band at each discharge, and I might weld in EGT bungs, but probably not. the taper is accomplished by cutting a long V-notch the length of a piece of pipe, and then clamping the pipe carefully to generate the taper.





    Last edited by ejs262; October 26, 2019, 09:53 PM.
    "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

    1985 Pontiac Fiero, 3.5 V6 turbo, 5 speed
    1988 Suburban, 350 TBI 700r4, 4x4
    2006 2500 HD 6.0 4x4

    Comment


    • #32
      I re-drew the header flange from square one, the only dimension in question at this point, is the distance between the ports, unfortunately, I don't have a accurate instrument that large, but they should be very close. the port outline is looks to be damn near perfect at this point, and I should no longer have any interference issues with the schedule 10 pipe either.

      "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

      1985 Pontiac Fiero, 3.5 V6 turbo, 5 speed
      1988 Suburban, 350 TBI 700r4, 4x4
      2006 2500 HD 6.0 4x4

      Comment


      • #33
        Originally posted by ejs262 View Post

        Unfortunately, I don't have the material yet, if you know of someone in the area who has 3/8 304 stainless flange material, on the shelf in less than giant quantities, I'd love to know! I'll let you know as soon as I have everything together!

        I got started on the new set of turbo manifolds, or at least the parts that I can without the flanges in hand.

        the forward most ports will use 90* bends. and the downstream ports will use 45*, contoured to the pipe. the main log is tapered from the 1.5" 90*, to a 2" discharge at the end. I plan to use a V-band at each discharge, and I might weld in EGT bungs, but probably not. the taper is accomplished by cutting a long V-notch the length of a piece of pipe, and then clamping the pipe carefully to generate the taper.




        Not on Sunday - but Whiteside usually has that stuff and will cut it. The problem is they are a 9-4pm (sometimes less) kind of place. Alternative is Metal Supermarket. I'll also mention this - Allied Steel in Redmond will use their laser and cut stuff out for pretty cheap (to the point that if they have it they usually don't charge enough for the metal - which makes the part basically the cost of the metal). There are a bunch of people who take small jobs - but Allied is the one I use... nice thing about laser is there is no slag, it's ready to weld out of the machine.

        That said, I think their stainless capacity is 5/16 - when I had them build flanges for my Fiat (3.6 motor), I had them cut out of 3/8 steel and I think the reason was their capacity.... it's been awhile so that may have changed...

        *allied builds railings - and they love these little keep-them-busy jobs for their laser.
        Doing it all wrong since 1966

        Comment


        • #34
          Originally posted by SuperBuickGuy View Post

          Not on Sunday - but Whiteside usually has that stuff and will cut it. The problem is they are a 9-4pm (sometimes less) kind of place. Alternative is Metal Supermarket. I'll also mention this - Allied Steel in Redmond will use their laser and cut stuff out for pretty cheap (to the point that if they have it they usually don't charge enough for the metal - which makes the part basically the cost of the metal). There are a bunch of people who take small jobs - but Allied is the one I use... nice thing about laser is there is no slag, it's ready to weld out of the machine.

          That said, I think their stainless capacity is 5/16 - when I had them build flanges for my Fiat (3.6 motor), I had them cut out of 3/8 steel and I think the reason was their capacity.... it's been awhile so that may have changed...

          *allied builds railings - and they love these little keep-them-busy jobs for their laser.
          Thanks, I'll have to check them out.

          I've been working on the engineering for the manifolds quite a bit over the past few days.


          https://www.engineeringtoolbox.com/t...pes-d_283.html

          according to this, over about 12"(approximate length of the log) of pipe, and a temperature difference of around 1300F from installed state to what is probably well over max operating temperature yields an expansion of about 0.2" similar math for the head, assuming 142F rise (due to coolant) results in an expansion of 0.022", a difference in expansion of .178"

          using the difference in temperature for the head, and the expansion of the stainless gives us an expansion of.019 for the flange, a difference of .003 between the head and flange, if I were a betting man, I would say that the flange is probably slightly hotter than the head, due to the lower thermal conductivity of stainless compared to aluminum, and the lack of cooling medium.

          knowing this, across the entire head, I have a difference of about .18" between the log and the flange. that I need to make up. but the force on the runners will be applied bidirectionally, with about .126" of expansion between the ports further apart, and about .054 between the ports close together.

          All of this is assuming steady state temperature, I imagine transient dT's would be lower.

          0.0195" head

          0.0167" flange
          0.01169" wide
          0.00501" narrow

          0.156" pipe
          0.098" wide
          0.042" narrow


          0.071" flange hot
          0.0497" wide
          0.0213" narrow

          difference warm
          0.0864 wide
          0.0369 narrow

          divergence warm
          3.62 degrees wide
          1.57 degrees narrow

          difference hot
          0.0483" wide
          0.0217" narrow

          divergence hot
          2.049 degrees wide
          0.92 degrees narrow


          on the front bank, most of the expansion can be taken up by the bend from the first port. as it should be relatively free to expand towards front passenger side of the engine compartment, on the rear bank, that expansion has to be taken between the ports, as both ports will discharge at almost right angles to the pipe. short of building a 3-1 header style manifold, I don't think there's much I can do there, slotting the boltholes at the ends of the flange would allow the pipe to move the flange to a small degree, but it will also be forced counter to that by it's lesser expansion, and would have to also fight the force applied by the tension of the bolts also resisting flange movement. I'm going to keep looking at them from an engineering standpoint, but I think what I have so far should perform adequately.
          "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

          1985 Pontiac Fiero, 3.5 V6 turbo, 5 speed
          1988 Suburban, 350 TBI 700r4, 4x4
          2006 2500 HD 6.0 4x4

          Comment


          • #35
            as long as each exhaust pipe has a bend in it, thermal expansion shouldn't be an issue - heat doesn't have to travel linearly, thus if you put a bend at the exhaust the expansion will make the pipe bulge at the outside of the radius.
            the other thing to consider is if you make the tolerance too tight, you'll put bolt heads off like happens on LS motors...
            and finally
            because the exhaust is flowing across the metal, the metal cannot get hotter then the exhaust flow.. you mentioned there is no cooling but there is through flow alone. Not just that but the heat will flow back into the head and be removed by the cooling.
            in my experience, the hottest place is the point of most restriction or lowest flow

            biggest issue to avoid is not to weld in a bow in the flange - I wish I had a large enough oven to temper exhaust manifolds. I agree with Al on Skid Factory, bolt your manifold to a inch thick (or thicker) flat plate then weld together.
            Doing it all wrong since 1966

            Comment


            • #36
              Originally posted by SuperBuickGuy View Post
              as long as each exhaust pipe has a bend in it, thermal expansion shouldn't be an issue - heat doesn't have to travel linearly, thus if you put a bend at the exhaust the expansion will make the pipe bulge at the outside of the radius.
              the other thing to consider is if you make the tolerance too tight, you'll put bolt heads off like happens on LS motors...
              and finally
              because the exhaust is flowing across the metal, the metal cannot get hotter then the exhaust flow.. you mentioned there is no cooling but there is through flow alone. Not just that but the heat will flow back into the head and be removed by the cooling.
              in my experience, the hottest place is the point of most restriction or lowest flow
              agreed, but realistically, there's no real bend in the areas I'm concerned about. I horizontally slotting the bolt holes for either end port will allow for proper clearance, the center port boltholes will be used to maintain a resting center position.

              Originally posted by SuperBuickGuy View Post
              biggest issue to avoid is not to weld in a bow in the flange - I wish I had a large enough oven to temper exhaust manifolds. I agree with Al on Skid Factory, bolt your manifold to a inch thick (or thicker) flat plate then weld together.
              100% agree, I was planning to bolt the flange to a spare head I have to facilitate that. SBC manifolds fit in my oven just fine, but it helps that I'm not married...

              "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

              1985 Pontiac Fiero, 3.5 V6 turbo, 5 speed
              1988 Suburban, 350 TBI 700r4, 4x4
              2006 2500 HD 6.0 4x4

              Comment


              • #37


                100% agree, I was planning to bolt the flange to a spare head I have to facilitate that. SBC manifolds fit in my oven just fine, but it helps that I'm not married...


                When we were welding up exhaust flanges at EPA we used some that were made out of SS sheet metal and they tended to warp during welding. The guys in the shop made up a 2" (+/-) block of steel with a split collar to blot the flange down to the block and then they welded away. No more warped flanges. Just sayin' that the concept is a good one.

                Dan

                Comment


                • #38


                  first ever attempts at welding stainless steel. I can tell already I need lots of practice. I think my travel speed is too slow, and I probably should have spent more time prepping the surfaces, I'm planning on picking up some stainless wire wheels tomorrow, and I'll use them to brush the weld areas, and then I'll wipe them, as well as the filler, with acetone prior to welding. I'm also going to use solarflux on the back of the weld to prevent pickling the backsides.
                  Last edited by ejs262; November 1, 2019, 06:59 PM.
                  "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

                  1985 Pontiac Fiero, 3.5 V6 turbo, 5 speed
                  1988 Suburban, 350 TBI 700r4, 4x4
                  2006 2500 HD 6.0 4x4

                  Comment


                  • #39
                    too hot, not clean enough (wire brush like you do with aluminum), move your torch in a circular pattern... still, not bad for a first shot
                    Doing it all wrong since 1966

                    Comment


                    • #40
                      Originally posted by SuperBuickGuy View Post
                      too hot, not clean enough (wire brush like you do with aluminum), move your torch in a circular pattern... still, not bad for a first shot
                      Thanks! I picked up some stainless wire wheels this afternoon, but I did forget acetone... DOH! I was running about 120 amps for that run, I think I am going to take it back to about 100-115, and move faster, hopefully that, and the better cleanup, nets me a better result.
                      "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

                      1985 Pontiac Fiero, 3.5 V6 turbo, 5 speed
                      1988 Suburban, 350 TBI 700r4, 4x4
                      2006 2500 HD 6.0 4x4

                      Comment


                      • #41
                        what is your welder?
                        Doing it all wrong since 1966

                        Comment


                        • #42
                          it's a Miller Diversion 180

                          a little less stickout, a litttle more prep, a little more speed, and a little less current netted this:



                          much better, but I still need more practice.
                          "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

                          1985 Pontiac Fiero, 3.5 V6 turbo, 5 speed
                          1988 Suburban, 350 TBI 700r4, 4x4
                          2006 2500 HD 6.0 4x4

                          Comment


                          • #43
                            there ya go. now to add filler as you're moving along and taper off on the heat at the end of the weld (to avoid the pinholes) but seriously, you're getting it
                            Doing it all wrong since 1966

                            Comment


                            • #44
                              I'd be proud of that weld! I think you're getting the hang of it.

                              Dan

                              Comment


                              • #45
                                Thanks guys! I've been practicing alot, I've done about 5 or 6 laps around some pipe, tomorrow I'm going to cut it apart and do it again, hopefully I can get them all looking great.
                                "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

                                1985 Pontiac Fiero, 3.5 V6 turbo, 5 speed
                                1988 Suburban, 350 TBI 700r4, 4x4
                                2006 2500 HD 6.0 4x4

                                Comment

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