17,5 ccm 4 stroke single cylinder engine

Discussion in 'A Work In Progress' started by stef110, Jan 27, 2019.

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  1. Jan 27, 2019 #1

    stef110

    stef110

    stef110

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    minh-thanh likes this.
  2. Jan 27, 2019 #2

    kuhncw

    kuhncw

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    Stef,

    Nice work!

    Chuck
     
  3. Jan 28, 2019 #3

    stef110

    stef110

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    Tnx im enjoying the build so far.

    I have a small question about the cylinder and piston. In the building plan they talk about a ductile graphite iron cylinder liner.
    And as a piston ring they recommend a st60 material.
    As a left over from my Debbie build i have a piece of GG25 cast iron left can i also use this for the cylinder liner?

    stef
     
  4. Feb 2, 2019 #4

    stef110

    stef110

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    This weekend i started on the cylinder head on the lathe. Today i did some cnc milling on it. onlything left to do is drill the hole for the glowplug. but it needs to be under an angle and there for i first need to buy some new tools.

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    stef
     
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  5. Feb 3, 2019 #5

    kadora

    kadora

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    Stef it will be really nice engine.
    Keep posting pictures.
     
  6. Feb 3, 2019 #6

    stef110

    stef110

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    Today i machined the back plate of the motor, and made the cylinder liner out of cast iron (gg25).
    My question till stays what material for the piston ring? can i also use the same cast iron for this?

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    stef
     
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  7. Feb 5, 2019 #7

    stef110

    stef110

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    Today i machined my first ever valve, i think it doesn't look to bad.

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    Stef
     
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  8. Feb 5, 2019 #8

    josodl1953

    josodl1953

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    Hi Stef,
    I think you'd better use a harder quality cast iron for the piston ring, for instance GGG 40 or 60. In general it is not a good idea to have identical materials of the same hardness running against each other.

    Jos
     
  9. Feb 5, 2019 #9

    OllyM

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    I've just made a start on this engine, really good to see the progress you're making, looks superb. How did you turn the radius on the valve stem? I'm planning on using a steel liner and ductile iron ring, but far away from making those bits yet.
     
  10. Feb 7, 2019 #10

    stef110

    stef110

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    I will find an harder cast iron for the piston ring then.
    This evening i finished my second valve, also the valve springs came in today.
    The radius on the valve is done with a round lathe tool insert (don't know the exact English word for the tool)
    Planing on making the piston this weekend.

    stef
     
  11. Feb 8, 2019 #11

    bluejets

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    I always do without any problems.
    Naturally the ring is heat treated in between a pair of specifically made relatively large steel blocks with wedges in the ring ends and then allowed to cool.
    Ring is then fitted to a mandrel for final turning to true the now slightly out of shape ring and to bring to final size.
    Plenty of info out there on how to do it.
     
  12. Feb 9, 2019 #12

    stef110

    stef110

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    Tnx bluejets for the info.

    Today did a lot of progress, valves are done including the springs underneath them and it seems to fit and seal well. Also made the crankshaft and the bearing blocks to support the crankshaft.

    stef

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  13. Feb 9, 2019 #13

    bluejets

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    Difficult to see exact detail on the valve caps but I tend to recess the circlip slightly into the cap.
    Makes sure it stays put. :)
    Nice work.
    Perhaps just a little commentary on materials used etc...??
     
  14. Feb 10, 2019 at 12:26 PM #14

    necchiom

    necchiom

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    Wow... Awesome work!
     
  15. Feb 11, 2019 at 8:24 PM #15

    stef110

    stef110

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    @bluejets
    It was a quick post so let me explain a little now.
    What you said about the circlip its true i re watched the drawing and there is a little chamber to lock the clip into will make them so make sure it stays on thanks for the notice.
    The camshaft i made from stainless steel it was the hardest material i had laying around. I first did the shafts on the lathe and then milled the cams on it with my 4th axis cnc.
    Today i ordered a carb and some glowplugs with a matching tap to cut the threads.
    So far iam really enjoying the build!

    Stef
     
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