Demon V8 (multiplied 1.5)

Discussion in 'A Work In Progress' started by Foketry, Sep 24, 2019.

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  1. Jan 17, 2020 #121

    Foketry

    Foketry

    Foketry

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    using the same system for all electrodes is not possible and not necessary
    it is not possible because the rotor electrode mills the graphite, it is like a small blade, not necessary because it must not be a sliding contact, only the central one must crawl
     
  2. Jan 17, 2020 #122

    Peter Twissell

    Peter Twissell

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    The other electrodes are not contacts, the rotor arm conductor doesn't touch them, just comes close enough for the spark to jump the gap.
     
  3. Jan 17, 2020 #123

    awake

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    That's interesting. Looking back to the days when I used to tune up my old Dodge Dart, I can remember having to assess whether the electrodes were too burnt and needed to be replaced.

    Which raises a question - as best I recall, the electrodes in that old Dart were brass. Wouldn't that burn up rather quickly from the jumping spark?
     
  4. Jan 17, 2020 #124

    Peter Twissell

    Peter Twissell

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    The spark is high voltage, but low current, so the heating effect at the relatively large surface of the electrode is small.
    By contrast, arcing at the low voltage breaker points carries several amps and will cause burning if it is not surpressed by a capacitor.
     
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  5. Jan 18, 2020 #125

    awake

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    Ah! That makes sense.
     
  6. Jan 20, 2020 #126

    Foketry

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    Intake manifold, not very easy to make the connection holes :confused:

    IMG_9413.JPG
    IMG_9414.JPG IMG_9415 (1).JPG
     
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  7. Jan 26, 2020 #127

    Foketry

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    Valve cover from round rod, before anodizing and after blue anodizing

    IMG_9494.JPG IMG_0212.jpg
     
  8. Jan 26, 2020 #128

    Foketry

    Foketry

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    I tried to anodize at home, with caustic soda and sulfuric acid, I followed the whole procedure seen on Youtube, but with poor results, aluminum does not take color.
    I did various experiments with different amperage and voltage, different types of aluminum, no results :(

    I brought all the pieces to be anodized by a artisan who in 2 days did a good job
     
  9. Feb 1, 2020 #129

    Foketry

    Foketry

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    Radiator from computer, it was necessary to modify the connections for water inlet and outlet and remove an internal bulkhead

    IMG_9495.JPG
     
  10. Feb 1, 2020 #130

    Foketry

    Foketry

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    the radiator before painting

    IMG_9497.JPG IMG_9519.JPG IMG_9522.JPG
     
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  11. Feb 2, 2020 #131

    bobden72

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    Great stuff
     
  12. Feb 6, 2020 #132

    Foketry

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    Finally, after some adjustments during the assembly of all the parts, the moment of camshaft timing has arrived.


    IMG_9392.JPG IMG_9394 (1).JPG IMG_9396.JPG
     
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  13. Feb 7, 2020 #133

    petertha

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    Wow you work fast. Fantastic!
    So what is the adjustment you 'lock in' in the engine? Looks like you achieve TDC on piston, match valve position from cam shaft lobe. Then does that mean the camshaft gear gets frozen in that position?
    Then what about distributor timing, how does that come into play?
     
  14. Feb 7, 2020 #134

    stevehuckss396

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    This is the procedure I used and it fired up and ran good enough to start fine tuning.

    Untitled.jpg
     
  15. Feb 7, 2020 #135

    Foketry

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    I followed the procedure indicated by the construction plans provided by Steven H, written in the next post no. 134
    in addition to this I checked the timing of each cylinder to check the correct construction of the camshaft (I have not published the photos of the camshaft construction because I have deleted them by mistake)

    I also followed this video made by DOC


    once the timing of the valves is ok I will make the setting of the distributor but first I have to assemble the heads and check the compression of each cylinder and do a little running in on the lathe, with the spindle that rotates the crankshaft
     
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  16. Feb 10, 2020 #136

    Foketry

    Foketry

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    Compression test
    This is the cylinder with the highest compression
    the worst is 4.5 bar the average is 5 bar
    I built 7 cast iron cylinders and 1 steel cylinder, there are no differences between them
    The compression test was done at around 1000 rpm
     
    Last edited: Feb 10, 2020
  17. Feb 10, 2020 #137

    Foketry

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  18. Feb 10, 2020 #138

    Peter Twissell

    Peter Twissell

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    I wonder what the volume of that gauge and the adaptor is. I expect your compression is higher than indicated.
    One way to prevent the gauge volume from altering your compression reading is to pre-fill the gauge and adaptor with oil, making its volume incompressible.
    Nice work on the engine!
    Re. Iron Vs steel liners, I would expect similar performance as machined. Any difference may show up after a few hours running.
     
  19. Feb 11, 2020 #139

    Foketry

    Foketry

    Foketry

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    This tool is built with a pressure gauge and a non-return valve from a bicycle wheel

    IMG_9118.JPG
     
    Last edited: Feb 11, 2020
  20. Feb 11, 2020 #140

    Foketry

    Foketry

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    yes, I agree, my pressure control gauge also adds the volume of the tube and the pressure gauge to the volume of the combustion chamber, so the value read on the graduated scale is not correct.
    I have always used this for all my small engines and this is my reference. I know that a pressure value below 2.5 bar is not good.
    I will follow your advice and will fill the tube with oil to eliminate the air inside and surely the pressure will increase.
     

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