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DT125R FORUM

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  4. The Helios Project (Aprilia RS 125 Rotax 122 Biaggi Race Replica)

The Helios Project (Aprilia RS 125 Rotax 122 Biaggi Race Replica)

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  • CalumC Calum

    Forged Piston Fitted.

    alt text

    alt text

    alt text

    alt text

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    Fitted it all nice and snug.

    Put the engine away, amazingly (luckily) found one of the circlips had fallen out onto the bench.

    Thankfully I found that, not sure how that happened. But that's back in now!

    Of course I have bought titanium head bolts for this engine. But I was too eager to bolt all the pieces together and they haven't arrived yet.

    But I will fit them when they arrive.

    Irongamer727I Offline
    Irongamer727I Offline
    Irongamer727
    wrote on last edited by
    #121

    @calum Oh my thats beautiful!
    Do you know how big the difference between the piston diameter and the cylinder diameter is? Or did the piston arrive with the cylinder perhaps? I've always been uncertain how big the difference should be when fitting a new piston.

    CalumC 1 Reply Last reply
    0
    • Irongamer727I Irongamer727

      @calum Oh my thats beautiful!
      Do you know how big the difference between the piston diameter and the cylinder diameter is? Or did the piston arrive with the cylinder perhaps? I've always been uncertain how big the difference should be when fitting a new piston.

      CalumC Offline
      CalumC Offline
      Calum
      wrote on last edited by
      #122

      @irongamer727 Yeah it probably says in the spec sheet it comes with. I didn't read it. You can tell the piston to cylinder clearances in this engine are large. However I woupd expect that from forged components due to their thermal expansion coefficient.

      For reliability I have knocked the compression back, this piston only utilises a single ring. Less frictional losses and bore wear

      Always Originate, Never Pirate!

      Irongamer727I 1 Reply Last reply
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      • CalumC Calum

        @irongamer727 Yeah it probably says in the spec sheet it comes with. I didn't read it. You can tell the piston to cylinder clearances in this engine are large. However I woupd expect that from forged components due to their thermal expansion coefficient.

        For reliability I have knocked the compression back, this piston only utilises a single ring. Less frictional losses and bore wear

        Irongamer727I Offline
        Irongamer727I Offline
        Irongamer727
        wrote on last edited by
        #123

        @calum thicker basegasket?

        CalumC 1 Reply Last reply
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        • Irongamer727I Irongamer727

          @calum thicker basegasket?

          CalumC Offline
          CalumC Offline
          Calum
          wrote on last edited by
          #124

          @irongamer727 exactly that.

          Always Originate, Never Pirate!

          1 Reply Last reply
          0
          • Irongamer727I Offline
            Irongamer727I Offline
            Irongamer727
            wrote on last edited by
            #125

            I guess you purchased the cylinderkit on PJME. I mean that was a pretty good price for it!

            I know you have bought the special cylinderhead and got it ported but still, I thought the cylinder would be like £600 or something.

            The polini big bore was a bit more. I guess you reckon you can get more power from your kit, but how?

            CalumC 1 Reply Last reply
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            • Irongamer727I Irongamer727

              I guess you purchased the cylinderkit on PJME. I mean that was a pretty good price for it!

              I know you have bought the special cylinderhead and got it ported but still, I thought the cylinder would be like £600 or something.

              The polini big bore was a bit more. I guess you reckon you can get more power from your kit, but how?

              CalumC Offline
              CalumC Offline
              Calum
              wrote on last edited by
              #126

              @irongamer727 So I didn't get this barrel ported. I just said that the porting work is damn good, albeit some minro flaws.

              The last RS in my garage used the Polini big bore, before the 140 kit was released.

              https://www.youtube.com/watch?v=GobIl4e-mU8&t=2s&list=PL66C1264C7D6205BB&index=3

              Very quick bike, but the Polini eventually seized after very little miles and most of it was being ridden softly.

              It was my brothers bike, but mi casa, su casa as the Spanish say.

              Big bores are hard on engines. It's not the first time I've said it, and it won't be the last, in my experience the Athena was pretty poor for performance. Reliable mind you.

              Always Originate, Never Pirate!

              Irongamer727I 1 Reply Last reply
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              • CalumC Calum

                @irongamer727 So I didn't get this barrel ported. I just said that the porting work is damn good, albeit some minro flaws.

                The last RS in my garage used the Polini big bore, before the 140 kit was released.

                https://www.youtube.com/watch?v=GobIl4e-mU8&t=2s&list=PL66C1264C7D6205BB&index=3

                Very quick bike, but the Polini eventually seized after very little miles and most of it was being ridden softly.

                It was my brothers bike, but mi casa, su casa as the Spanish say.

                Big bores are hard on engines. It's not the first time I've said it, and it won't be the last, in my experience the Athena was pretty poor for performance. Reliable mind you.

                Irongamer727I Offline
                Irongamer727I Offline
                Irongamer727
                wrote on last edited by
                #127

                @calum so the polini isn't very reliable then?
                I've heared the same. I'm happy with the Athena though. Strong, not very fast but comfortable.

                CalumC 1 Reply Last reply
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                • Irongamer727I Irongamer727

                  @calum so the polini isn't very reliable then?
                  I've heared the same. I'm happy with the Athena though. Strong, not very fast but comfortable.

                  CalumC Offline
                  CalumC Offline
                  Calum
                  wrote on last edited by
                  #128

                  @irongamer727 Good torque gains from the Athena, if that what you're after. And, unlike the Polini, doesn't affect reliability.

                  I can only comment on my own experiences, and that may have been down to incorrect jetting. As this wasn't my bike I wasn't at liberty to jet it as I saw fit.

                  The reason I went with the 140 kit, is that I am not interested in more CC's, I want it to rev to the moon and the fact that the person who designed this designed the original. It was also (as you say) cheap. Just £40 more than having my old barrel replated and ported with a new piston. Something different as well, I've not experienced this cylinder before.

                  I'm excited 😄 Still £2k of bits left to buy for this bike yet.

                  Always Originate, Never Pirate!

                  Irongamer727I 1 Reply Last reply
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                  • CalumC Calum

                    @irongamer727 Good torque gains from the Athena, if that what you're after. And, unlike the Polini, doesn't affect reliability.

                    I can only comment on my own experiences, and that may have been down to incorrect jetting. As this wasn't my bike I wasn't at liberty to jet it as I saw fit.

                    The reason I went with the 140 kit, is that I am not interested in more CC's, I want it to rev to the moon and the fact that the person who designed this designed the original. It was also (as you say) cheap. Just £40 more than having my old barrel replated and ported with a new piston. Something different as well, I've not experienced this cylinder before.

                    I'm excited 😄 Still £2k of bits left to buy for this bike yet.

                    Irongamer727I Offline
                    Irongamer727I Offline
                    Irongamer727
                    wrote on last edited by
                    #129

                    @calum it's going to be interesting to hear how she runs!

                    CalumC 1 Reply Last reply
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                    • Irongamer727I Irongamer727

                      @calum it's going to be interesting to hear how she runs!

                      CalumC Offline
                      CalumC Offline
                      Calum
                      wrote on last edited by
                      #130

                      @irongamer727 Yeah sure, I expect it to be...disappointing lol. If I bought a rag around RS and bolted on a cylinder kit then yeah, fair enough. But having been building it for nearly 3 years, the expectations are too grand.

                      Always Originate, Never Pirate!

                      declanD 1 Reply Last reply
                      0
                      • CalumC Calum

                        @irongamer727 Yeah sure, I expect it to be...disappointing lol. If I bought a rag around RS and bolted on a cylinder kit then yeah, fair enough. But having been building it for nearly 3 years, the expectations are too grand.

                        declanD Offline
                        declanD Offline
                        declan
                        wrote on last edited by
                        #131

                        @calum nah I expect that it will make it all the sweeter to ride

                        1 Reply Last reply
                        0
                        • CalumC Offline
                          CalumC Offline
                          Calum
                          wrote on last edited by
                          #132

                          Another delivery of goodies arrived!

                          I think this is shamefully about all I can afford this month 😞

                          alt text

                          alt text

                          Brand new set of mirrors

                          alt text

                          Now, I skimped out here. Samco hoses are around £100, but I got these from China for like £35

                          alt text

                          To be honest with you, they're banging for the money. Maybe I'll get the samco ones further down the line, although I doubt it.

                          Always Originate, Never Pirate!

                          NINJAN 1 Reply Last reply
                          1
                          • CalumC Calum

                            Another delivery of goodies arrived!

                            I think this is shamefully about all I can afford this month 😞

                            alt text

                            alt text

                            Brand new set of mirrors

                            alt text

                            Now, I skimped out here. Samco hoses are around £100, but I got these from China for like £35

                            alt text

                            To be honest with you, they're banging for the money. Maybe I'll get the samco ones further down the line, although I doubt it.

                            NINJAN Offline
                            NINJAN Offline
                            NINJA
                            wrote on last edited by NINJA
                            #133

                            @calum Give your wallet a rest this month dude, it's been busy enough lately. :face_with_tears_of_joy:

                            And where did you get the reeds from, was it a good deal???

                            SEDUCED BY THE DARK SIDE!!!

                            CalumC declanD 2 Replies Last reply
                            0
                            • NINJAN NINJA

                              @calum Give your wallet a rest this month dude, it's been busy enough lately. :face_with_tears_of_joy:

                              And where did you get the reeds from, was it a good deal???

                              CalumC Offline
                              CalumC Offline
                              Calum
                              wrote on last edited by Calum
                              #134

                              @ninja That all totals to about £300.

                              I buy all my stuff from PJME, since they're reputable.

                              The V Force reeds were £160.

                              Always Originate, Never Pirate!

                              1 Reply Last reply
                              1
                              • NINJAN NINJA

                                @calum Give your wallet a rest this month dude, it's been busy enough lately. :face_with_tears_of_joy:

                                And where did you get the reeds from, was it a good deal???

                                declanD Offline
                                declanD Offline
                                declan
                                wrote on last edited by
                                #135

                                @ninja bet he goes through wallets like anything with all the friction of taking money out lol

                                CalumC 1 Reply Last reply
                                2
                                • declanD declan

                                  @ninja bet he goes through wallets like anything with all the friction of taking money out lol

                                  CalumC Offline
                                  CalumC Offline
                                  Calum
                                  wrote on last edited by
                                  #136

                                  @declan Right, so if you just want to tell the missus that, that would be great...

                                  Always Originate, Never Pirate!

                                  declanD 1 Reply Last reply
                                  0
                                  • CalumC Calum

                                    @declan Right, so if you just want to tell the missus that, that would be great...

                                    declanD Offline
                                    declanD Offline
                                    declan
                                    wrote on last edited by
                                    #137

                                    @calum lol did you get those hoses direct from China or just made in China either way they’re nice

                                    CalumC 1 Reply Last reply
                                    0
                                    • declanD declan

                                      @calum lol did you get those hoses direct from China or just made in China either way they’re nice

                                      CalumC Offline
                                      CalumC Offline
                                      Calum
                                      wrote on last edited by
                                      #138

                                      @declan Direct from China, like alibaba style.

                                      alt text

                                      Engine built, I will clean the carb tomorrow to make it spanking.

                                      Titanium bolts mount the intake to the engine. Along with my powdercoated skull cap, which should contrast nicely with my NGK racing coil and HT Lead, along with the red engine mount.

                                      Just awaiting on some carbon from America, my on going Hydraulic clutch conversion, then this engine is ready to rock and roll.

                                      And for those interested in the hydraulic clutch conversion, it would appear, after much discussions with far more qualified engineers, that the solution the other chap derrived is not adequate.

                                      I will explain in a separate thread, but basically it's gone from being very easy, to needing a bit more thought...but more on that when it's finished.

                                      Always Originate, Never Pirate!

                                      NINJAN 1 Reply Last reply
                                      0
                                      • CalumC Calum

                                        @declan Direct from China, like alibaba style.

                                        alt text

                                        Engine built, I will clean the carb tomorrow to make it spanking.

                                        Titanium bolts mount the intake to the engine. Along with my powdercoated skull cap, which should contrast nicely with my NGK racing coil and HT Lead, along with the red engine mount.

                                        Just awaiting on some carbon from America, my on going Hydraulic clutch conversion, then this engine is ready to rock and roll.

                                        And for those interested in the hydraulic clutch conversion, it would appear, after much discussions with far more qualified engineers, that the solution the other chap derrived is not adequate.

                                        I will explain in a separate thread, but basically it's gone from being very easy, to needing a bit more thought...but more on that when it's finished.

                                        NINJAN Offline
                                        NINJAN Offline
                                        NINJA
                                        wrote on last edited by
                                        #139

                                        @calum A multi coloured engine - unusually sweet! VHSB 34mm carb is it? And did your carb come with that top cap or did you source it from somewhere???

                                        SEDUCED BY THE DARK SIDE!!!

                                        CalumC 1 Reply Last reply
                                        0
                                        • NINJAN NINJA

                                          @calum A multi coloured engine - unusually sweet! VHSB 34mm carb is it? And did your carb come with that top cap or did you source it from somewhere???

                                          CalumC Offline
                                          CalumC Offline
                                          Calum
                                          wrote on last edited by
                                          #140

                                          @NINJA It's the racing version of the VHSB carb.

                                          alt text

                                          It's like an extra £100.

                                          Always Originate, Never Pirate!

                                          NINJAN 1 Reply Last reply
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