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  1. Foketry

    Porsche 917 flat 12 engine

    Another step forward for camshaft I have temporarily installed the camshafts complete with bearings, aluminum spacers , gear ,intake and exhaust cams , now are locked in position by M3 grub screw . Still to be done: timing, drilling hole for spring pins to lock cams on the camshaft, complete...
  2. Foketry

    Porsche 917 flat 12 engine

    A further test: transmission gears between crankshaft and camshafts, 15 gears in total :7 gears on the left, 7 on the right, one in the crankshaft
  3. Foketry

    Porsche 917 flat 12 engine

    Bearing alignment test to be sure that all bearings rotate well, therefore well aligned and not deformed by the caps I did this test , without gears and cams
  4. Foketry

    Porsche 917 flat 12 engine

    To finish the caps, with the correct size so as not to deform the bearings or, on the contrary, leave gap, I measured the seats one by one to mill the cap the finishing milling of the caps
  5. Foketry

    Porsche 917 flat 12 engine

    Milling of bearing seats and the surface for cover on the camshaft housing the planes to be milled are inclined, I built a simple equipment to clamp the camshaft housing in the correct position , at the right angle Note the holes closed with brass screws, I corrected an error
  6. Foketry

    Porsche 917 flat 12 engine

    The casting caps first machining, 3 mm hole and counterbore second machining, roughing of the bearing seat and face milling third machining, separation of the caps with 4 mm end mill , the caps are locked with a jig
  7. Foketry

    Porsche 917 flat 12 engine

    To avoid complex machining I made 5 aluminum castings, each with 7 joined pieces, I made patterns with 3D printer the shape patterns on sand, the shapes below are for other pieces to make a modification in my CNC milling machine The furnace with molten aluminum
  8. Foketry

    Porsche 917 flat 12 engine

    Bearing caps for camshafts As the original Porsche engine I made 8 supports for each camshaft, the camshaft slides directly into the hardened and lubricated aluminum seats. My poor technology does not allow me to harden the aluminum, so I put 8 small bearings on each camshaft Each bearing will...
  9. Foketry

    Porsche 917 flat 12 engine

    yes, I will make a small hole in center to relieve pressure, when all tappet thicknesses will be fine-tuned
  10. Foketry

    Porsche 917 flat 12 engine

    In general, all engines with overhead camshafts have shims under the tappets, in my case since this engine will work a few hours in its life and therefore will not need to be adjusted due to wear, I prefer to lower the thickness by turning, one by one , do shims means have at least 24 pieces in...
  11. Foketry

    Porsche 917 flat 12 engine

    Valve tappets , qty 24 Are made of bronze and kept in axis by an external steel bushing. The ratio between tappet diameter and bushing length is greater than 1.5 to ensure linear sliding without jamming , everything will be lubricated with good quality permanent grease. Steel bushings are fixed...
  12. Foketry

    Porsche 917 flat 12 engine

    Are commercial gears, available at any bearing shop. Module 1, 32 teeth Involute gear cutters is much more expensive than commercial gears, some different sets would be needed depending on the number of teeth.
  13. Foketry

    Porsche 917 flat 12 engine

    The 4 gears for 4 camshafts, each gear has 3 timing slots , each cam can be adjusted independently
  14. Foketry

    Porsche 917 flat 12 engine

    the fixing screws are only for timing, the engine cannot work, I will put sprig pins to prevent the cam rotating on the shaft. In the cam drawing you can see the hole for screw and 2 pin holes All the cams, once the timing has been carried out, will be take apart and hardened. This engine, if I...
  15. Foketry

    Porsche 917 flat 12 engine

    the cams will be fixed to the shaft initially with a screw, when the timing is ok, they will be locked in position with a spring pin The bearings will be held in position by bearing caps and spacers between the end of the cam and bearing . I will do this assembly in a few weeks, I am waiting for...
  16. Foketry

    Porsche 917 flat 12 engine

    The camshaft design Camshaft will rotate on 6x12x4 2Z ball bearings, 8 each shaft , the gear in the center of the shaft will have a phase adjustment by means of 3 slots and 3 M3 screws. This will allow me to adjust the opening between the 2 camshafts, about 110/120 degrees, once the cams have...
  17. Foketry

    Porsche 917 flat 12 engine

    the pre-turned steel round ready for milling milling with a 6 mm end mill
  18. Foketry

    Porsche 917 flat 12 engine

    Cams I designed 2 different cams, one for intake and the other for exhaust as the duration of the intake and exhaust phases is different , 14 degrees greater the exhaust . I used hardenable steel, the tempering will have after having assembled everything with the correct timing and fixed in...
  19. Foketry

    Model engine CDI easy and cheap

    It works :p Thanks for all
  20. Foketry

    Model engine CDI easy and cheap

    Excellent job ! Could you also indicate the values of the resistances, the type of Hall sensor, the connections with the CDI and with the relay coil ? I would like to replicate your schema, could you write the values on the sheet I saw in the video, thanks
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