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FE DOHC 2.2 project

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    #61
    Here's more from the MPS6(MS6) training manual...
    Pretty much confirms the differences between A26M-R and A26MX-R are moderate at worst. I'm not having plans on AWD-MX6 though, it needs application specific control boxes that aren't too plentiful and trying to get it approved would truly be a nightmare. And with a turbo there is no possibility for approval.

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      #62
      One of the last missing key pieces of the engine is one step closer to the finish line:



      The tube parameters, 40x2mm at 60mm bend radius were dictated by the available material. There's still a tiny bit of slack in the design, but I believe that's the final general arrangement. The flange is split T4, and the exhausts are arranged in the proper 1+4/2+3 order , on left and right turbine ports. The turbine is near the centerline of the car, to give it a bit more hood clearance. It's likely the hood still needs to be modified to make the turbo fit, but that might just as well be, since I'm planning on an Evo-style hood vent anyway. The exhaust tubes flare at the exhaust port flange. This is to distribute the loads to a greater area, and also to provide anti-reversion. Also it simply looks much better.

      The material is AISI 309 heat resistant stainless steel. It's primary uses are for kiln liners, furnaces, boilers and car exhausts. It's very resilient to cracking up to 950 degrees C with intermittent heating (furnaces that don't have thermal cycles can go higher) and won't start to scale until around 1030 degrees. I expect the exhaust should last for a long time.

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        #63
        I took a look in your gallery & noticed anti reverberation pockets... think that will be a large benifit?

        any plans to make more then 1 of these flanges??

        Also where are you sourcing this 309 SS? I haven't heard of that before. How do you plan to weld it?
        ---Has ClubProtege helped you in someway? show your support by Contributing--- Click Here---

        1992- project FE3..... 313 WHP @ 9.3psi




        I pet my dash when I get into the car..."good car"
        he actually has a mazda tree, parts grow on it

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          #64
          I don't know how much and what kind of effect the antireversion pockets would have... I followed literature that stated it's a good thing to have, and on the forums say they're terrible and kill power, others say they're awesome and make the engine so much better, so I don't know really. However, the advice is the cones should be as close to the exhaust flange, and going 8mm into the flange, I can't think of much closer placement The 40x2mm (36mm inner diameter) tubing is actually just slightly smaller than the exhaust port area (the area is equivalent to 36.8mm diameter circle), so smooth transition was needed.

          EDIT: I'll rephrase myself a bit here. As the theory goes, anti-reversal cones/pockets are to prevent the reflecting shockwave from entering the cylinder and screwing up the gas dynamics within. A point against the pockets is there should be very little of reflected shockwaves with a twin-scroll turbo and properly arranged arranged pulses, and the pockets would just cause interfering turbulence. However nothing is ever simple and absolutes are preciously rare in engine tuning business, so I'll include them into the design and see how they'll work for me.

          About the flange, I have further ideas on how to refine it. Though it's most critical with log style manifolds, the differential thermal expansion in the exhaust tubing and the flange will cause warping and all kinds of undesirable effects. So, instead of having one, I was thinking of having and individual flange for each port. It's not as easy with FE as it is with some other engines, as each of the bottom three bolts are shared with two ports. The usual method is cutting the flange apart at the center, leaving a half-circle under each nut. I don't like this solution very much, so I'm considering an older solution; the shared studs are fitted with a strap clamp which seat onto both flanges and thus provide independent fastening for each flange and solid circle for the nut. There are some issues that might prevent using it, but I'm going to look at it (this similar solution was used in eg. Daimler-Mercedes engines during The Great War and Armstrong Siddeley car engines, it's a good method.
          Last edited by STW; 03-21-2014, 10:02 AM. Reason: Not to sound like a damn fool.

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            #65
            The part about SS309 got nuked, strange.... probably deleted it myself on some re-edit.

            Anyway, there is a local webshop (AMW Dyno Services) who produce these rather exact bends for exhaust use... but the price is pretty steep as said. VAT is 24% though, so non-eu customers will get quite a bit of discount on the price)

            I have (access to) GTAW/TIG welding equipment, so I'll be using that. Some years ago I did welder certification too, so welding won't be a problem. My bandsaw is pretty crappy though, getting the cuts true and square is perhaps the greatest challenge in the build.

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              #66
              very intrigued to see some pictures of that metal arise. & keep me in the loop on flange variations you might use.
              ---Has ClubProtege helped you in someway? show your support by Contributing--- Click Here---

              1992- project FE3..... 313 WHP @ 9.3psi




              I pet my dash when I get into the car..."good car"
              he actually has a mazda tree, parts grow on it

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                #67
                I did a mock-up with proper parts I found after frantic search. Here it is:



                There are few important interface pieces still missing, such as the intake part of the supercharger, pulley, top part of the supercharger and the aftercooler. It'll be a tight fit.

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                  #68
                  Did you model those yourself??
                  1991 Capri XR2 "GTXR2" BPT AWD Bastardization/conversion
                  1991 Isuzu Impulse RS Turbo AWD

                  Creator of the B6T Rocketchip
                  www.werbatfik.com

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                    #69
                    Everything except the turbo, which I couldn't bother. I did the head in 2009, I need to finish it someday.

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                      #70
                      I assembled the scrap head and scrap block for a pattern engine, and mocked up the supercharger position. Not encouraging. I have the full M65 setup with OEM supercharger cover, and it brings the return duct *very* close to the exhaust. I took some crappy photos with my super-terrible phone cam:




                      The perspective distortion doesn't indicate how damn tight those are. The top of the arch is closer than 110mm vertical and 130mm horizontal from the exhaust port center on the exhaust mating surface.

                      The lower coolant hose can be seen in the vertical photo. It may allow a 1-1.5 cm crawl room towards the radiator (can't understand why it's called radiator, it works through convection) but that's still quite tight.

                      I have to raise the turbo again by perhaps 10mm and re-arrange the exhaust into tighter package still, and see that cylinder 3 & 4 exhaust are routed far enough left to clear the ductwork.

                      at 800USD a piece, you don't want to make too many test exhausts!

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                        #71
                        Toilet paper rolls and tape. Make a mock up


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                          #72
                          I'd need to cut a hell of a lot of slits to bend the toilet roll tubes... the runners have very little straight tubing, total for all four is 400mm.

                          I figured some changes might be needed. The standard radiator may need to go. To reduce cooling needs, I could coat the combustion chambers and exhaust ports with ceramic heat barrier (and piston tops too, with heat dissipation coating on the underside to increase heat transfer to oil) Then, I could use waterless coolant which allows the engine run at much higher temp than the boiling point of water (it's fine, the engine actually likes to run a bit hot as long as the coolant doesn't boil); greater temperature difference increases cooling effect, and staying with E85 on all of the more spirited driving sessions will further reduce the heat load. The replacement radiator will be the funny 1910-esque civic 370x460mm radiator, which fits great between the headlight post, on the forward side of the radiator frame.

                          Such an arrangement would free up cool 60mm of extra clearance forward, giving much more freedom to play with the setup.
                          Last edited by STW; 03-28-2014, 03:59 PM.

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                            #73
                            60mm makes a world of a difference. I needed to rethink my radiator for the forward clearance too. & my setup is not anywhere near as complex.
                            keep up with the updates!
                            ---Has ClubProtege helped you in someway? show your support by Contributing--- Click Here---

                            1992- project FE3..... 313 WHP @ 9.3psi




                            I pet my dash when I get into the car..."good car"
                            he actually has a mazda tree, parts grow on it

                            Comment


                              #74
                              The frame forward radiator should help a great deal indeed... I quess it pretty much precludes any chance for an A/C installation though.

                              I bought the driveshaft for the new gearbox, and like before, beastly is the word that first comes to mind, again. Here we go:



                              Above are the new parts, below are the original. It almost looks as if the A26 parts were much closer to the camera, especially the intermediate shaft. The original shaft is 24mm in diameter, the new one is 37, and the splines are just enormous compared. The difference with half shafts are lesser, but still considerable. The shaft is 28mm vs 24 on the G-type, and the splines are enormous. The next photos will highlight the differences.


                              You'd think the new shaft end was much closer to the camera, but they're pretty even. The apparent difference in size is pretty much the actual difference in size.


                              The length of the splined parts are constantly almost twice the original, and much larger in other dimensions too. The spline diameter on the new parts is 32mm, where in the original G-type it's 26mm.


                              Peculiarily, the drive shaft splines are shorter than original. They are, however, thicker by a considerable margin.

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