Porsche 917 flat 12 engine

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drilling, internal turning and lapping to obtain the same internal dimension for all cylinders

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Lapping with DIY lap

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I just found this thread. Very impressive work! I drove through Modena on my way to Bologna. I visited the Ducati factory which was excellent.

Enjoy your freedom next week.

Great ! in Modena and Bologna you can also visit Ferrari, Lamborghini and Pagani car factories as well as some car museums
Thanks , from Monday I will finally be able to enjoy my freedom
 
Gear box for overhead camshafts
there are 4 camshafts, 2 for the 6 cylinders on the right, 2 for the cylinders on the left
From the center of the crankshaft a central gear transmits the rotation: under the oil pump shaft, above the 2 distributors and the fan, right to the 2 camshafts (ratio 1: 2), left to the other 2 camshafts (ratio 1: 2)

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Your castings look fantastic and would love know a little more about your process for casting. what materials you used for the metal (clean store bought Aluminum?? Your formula for the sand mixture, and what grit of sand you used.
I will definitely be following this article and discussion.
What type of plastic do you use with your 3D printer to achieve such beautiful results, maybe a few setting on your printer (if it's outside of the default settings) might help me.

Brian
 
Your castings look fantastic and would love know a little more about your process for casting. what materials you used for the metal (clean store bought Aluminum?? Your formula for the sand mixture, and what grit of sand you used.
I will definitely be following this article and discussion.
What type of plastic do you use with your 3D printer to achieve such beautiful results, maybe a few setting on your printer (if it's outside of the default settings) might help me.

Brian

In my garden foundry I now only use one type of aluminum (AlSi9Cu1 ) without any additives such as salt, baking soda or degassing tablets.
This type of aluminum also allows to be hardened in water to increase workability and mechanical strength.
In the past I tried to melt aluminum scraps of unknown provenance, with poor results, low mechanical strength and a lot of porosity.
About sand I use a first layer of Petrobond (expensive) in contact with the mold and filling with green sand( cheap)
The printer I used for molds is a resin SLA printer, default settings, the molds is very defined because the layers are 0.05 mm instead of 0.2 / 0.3 mm of an FDM printer.
I can recommend you this youtube video of this english guy, expert in foundry and printers, his videos have taught me many things

 
Outstanding work!
 
The heads , there are twelve, one for each cylinder, I initially thought of making them through aluminum casting but the cooling fins are very thin and my low foundry technique does not allow me to make these small thicknesses.
I bought a rectangular aluminum bar and cut 12+1 slices

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The heads , there are twelve, one for each cylinder, I initially thought of making them through aluminum casting but the cooling fins are very thin and my low foundry technique does not allow me to make these small thicknesses.
I bought a rectangular aluminum bar and cut 12+1 slices

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I like how you said “cut 12 +1” ;)
 
I just noticed how incredibly thin the valve seat is on the original head. That contact area can’t be but 1 or 2 millimeters! Amazing technology, I wonder what that insert is made of to withstand the heat and not burn out? Unless that’s a 2 step seat, I can’t believe the thin aspect of the outer seating ring surface.
 
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