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    Modifying cam gears

    Gents,

    Any PFers capable of doing some [from my understanding] pretty basic machining work or have access to someone that can do it? Basically, i have two cam gears i need modified to be adjustable. My understanding is it would be fairly simple for someone with access to a lathe - cut centre out of standard gear, drill PCD, machine new centre with slots, bolt together.

    Any takers? Ive no idea what grade alloy would be required so i would be relying on you [or whoever it is you know] to provide as part of process. If this is you, please PM me with $$$ in mind.

    Probably shouldve put this in jobs for the boys but whatevz
    1978 Gemini Sedan - Powered by i change my mind every week
    1980 Gemini Sedan
    1992 Land Rover Discovery 200TDI

    #2
    6061 t6 for the new centre is prob fine and common as.
    3D scanning
    3D modelling
    Structural certification
    3 and 5 axis milling

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      #3
      What engine? If it's Isuzu no luck, but mate has a few different Jap cam wheels from the last century and this, drilled and tapped and a few blank centres. No chance of him taking on the job as recovering from surgery.

      Have found with one morse chain driven wheel at least, they're were as hard as hades, so not as straightforward as just running a boring bar through them with standard inserts. I'd expect you'd need to send the cams to whoever does the job if you're doweling too.

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        #4
        Originally posted by PLAYA View Post
        6061 t6 for the new centre is prob fine and common as.
        Ta mate, handy to know. Anything else you reckon is relevant/i need to know?

        Originally posted by gxxr View Post
        What engine? If it's Isuzu no luck, but mate has a few different Jap cam wheels from the last century and this, drilled and tapped and a few blank centres. No chance of him taking on the job as recovering from surgery.

        Have found with one morse chain driven wheel at least, they're were as hard as hades, so not as straightforward as just running a boring bar through them with standard inserts. I'd expect you'd need to send the cams to whoever does the job if you're doweling too.
        Yep, Isuzu DOHC which is why itll need to be a custom job as i doubt anything out there would come remotely close to being suitable without machining work. Thing is, never had anything like this made up so ive got NFI where to start
        1978 Gemini Sedan - Powered by i change my mind every week
        1980 Gemini Sedan
        1992 Land Rover Discovery 200TDI

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          #5
          Got a photo?
          I wonder how far off Alfa cam wheels would be (Which are vernier adjustable in the true sense of the word, not slotted "pinch and pray")
          "Where can we get hold of a Vincent Black Shadow?" "Whats that?" "A fantastic bike," I said. "The new model is something like two thousand cubic inches, developing two hundred brake-horsepower at four thousand revolutions per minute on a magnesium frame with two styrofoam seats and a total curb weight of exactly two hundred pounds."

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            #6
            Ill go one better.



            Standard gear on right, gear with centre cut out on left



            Adjustable insert



            Completed assembly

            To me it looks like the pre-existing half-depth holes on the cam gear have been drilled and tapped
            1978 Gemini Sedan - Powered by i change my mind every week
            1980 Gemini Sedan
            1992 Land Rover Discovery 200TDI

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              #7
              Reacon I could pull this off with my shit in my shed.
              Ie lathe, mill, rotary table etc
              Have never done anything like that so nfi on $$ as dunno how much time.

              I don't have any alloy suitable but do have a lump of 4 inch round steel that would certainly do the job.

              On the other side of the country though.

              Comment


                #8
                Yeah, it's a lathe + Mill job, suspect that it's going to be as hard as fuck for part of that facing operation (says the guy who lightened a bunch of gearbox gears with no coolant and totalled ~3 tungsten carbide tip tools).
                Are there other G180W/G200W wierdos that would want a set?
                "Where can we get hold of a Vincent Black Shadow?" "Whats that?" "A fantastic bike," I said. "The new model is something like two thousand cubic inches, developing two hundred brake-horsepower at four thousand revolutions per minute on a magnesium frame with two styrofoam seats and a total curb weight of exactly two hundred pounds."

                Comment


                  #9
                  I don't reckon it will be way hard not like it's been case hardened like gearbag stuff.

                  My guess would be a high carbon steel that is heat treated on the teeth of the sprocket and not in the centre shown in the pics of the machining marks don't look like hardened steel.

                  Comment


                    #10
                    Metallurgy isnt my strong point but i reckon Morcs is right in that the heat treating is on the outer edge looking at the picture; possibly on the nose that slips over the cam as well to stop it beating itself to death?

                    Negative on any other G180Weirdos/G200Weirdos - all of them are serial procrastinators that hoard shit and talk about what they are going to do but dont actually do it hence i suspect it may be a one-off job for someone using a manual lathe/mill [i take it you were asking from a CNC perspective; quick batch run?]

                    Morcs, where abouts is the other side of the country? Happy to provide the correct material/cash for the correct material....just need you to be confident because i dont have a spare set of OEM gears to fall back on lol
                    1978 Gemini Sedan - Powered by i change my mind every week
                    1980 Gemini Sedan
                    1992 Land Rover Discovery 200TDI

                    Comment


                      #11
                      Originally posted by Morcs View Post
                      I don't reckon it will be way hard not like it's been case hardened like gearbag stuff.

                      My guess would be a high carbon steel that is heat treated on the teeth of the sprocket and not in the centre shown in the pics of the machining marks don't look like hardened steel.
                      I was just going on the heat treat "tide mark" that's been partially machined into. I'm actually surprised that it's only the teeth that have been hardened - pretty much every other sprocket I've seen has been Case hardened everywhere or through hardened and is as hard as fuck - sparks coming off the end mill type hard.
                      "Where can we get hold of a Vincent Black Shadow?" "Whats that?" "A fantastic bike," I said. "The new model is something like two thousand cubic inches, developing two hundred brake-horsepower at four thousand revolutions per minute on a magnesium frame with two styrofoam seats and a total curb weight of exactly two hundred pounds."

                      Comment


                        #12
                        Hit it with a file if it skates off it's hard as
                        If it actually takes a bite it will machine easy.

                        The gear bit is the easy bit fairly straight forward if it is soft enough.
                        It's the lining of everything up that I'm worried about ie setting the degree marks in correct position and the timing in correct position.
                        As I can't see from pics how sprocket is located to time sprocket to cam.
                        The rest is pretty straight forward.


                        Sprockets i if played with have machined with out drama but all are from low powered agricultural equipment or motorcycle stuff.

                        Remote WA pm

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                          #13
                          Looks like just the teeth have been induction hardened, reckon the rest might be ok. The hard ones here were some sort of sintered shit, needing a trip to SEI carbide, those bastards were hard all the way through, thankfully didn't have to try to tap them, as I used buttons in the lightening holes to hold it together - horrible noise in the cut even so.

                          Bit surprised that centre doesn't appear to have any positive location, other than the fastener, unless there's blind holes not shown? Some of the modern stuff uses diamond impregnated washers to accomplish the same...leery of that method in modded cars with high seat pressures!

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                            #14
                            Actually looking at the pic on pc there is a dowl alinging cam to sprocket fairly simple.

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                              #15
                              Not quite what you’re asking for, but I vaguely recall Rollmaster made a timing chain set for these. If they did, most of their models feature adjustable sprockets. But, from very limited memory here, I think they were pulled from the market.
                              Might be worth searching to see if anything is available, or even if anything secondhand is available.

                              Edit, also search JP brand.

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