Bugatti straight 8 cylinder with blower, design, 3D printed molds, castings , machining, assembly

[Foketry]

It is nice to see more Bugatti engines being built. I too started with the Pocher model for inspiration. I've gotten as far as making 3D printed PLA patterns to allow me to make rubber molds and then to make lost wax patterns. It's a lot of work and a lot of unknowns since the Bugatti Trust doesn't have any general arrangement plans for this engine. Here are two images of the 3D design I made for the cylinder block and oil sump.

Your design is the same as the original engine, a single cast iron block with head and cylinders.
I simplified the project by designing separate pieces, crankshaft case, cylinder block, 3-piece head,
my low casting technology does not allow me to make a single cast iron piece
Even my LPG foundry does not reach the temperature for cast iron.
For small and complicated pieces, for example compressor with fins, I think to use lost PLA and plaster technique

if you want to see the engine disassembled, there is a youtube video

 

[awake]

Foketry, great work on the castings, and I especially like the picture in IMG_0397!

 

[Doug Cygan]

Your design is the same as the original engine, a single cast iron block with head and cylinders.
I simplified the project by designing separate pieces, crankshaft case, cylinder block, 3-piece head,
my low casting technology does not allow me to make a single cast iron piece
Even my LPG foundry does not reach the temperature for cast iron.
For small and complicated pieces, for example compressor with fins, I think to use lost PLA and plaster technique

if you want to see the engine disassembled, there is a youtube video

I've seen that video before and it helped a lot with the design aspects. I have never tried cast iron before so that will be a challenge. I'd rather find a small foundry that could do it at a limited cost. The other option is for me to cast the cylinder head out of aluminum or white bronze and sleeve the cylinders and install hardened valve seats.

 

[Foketry]

The cylinder block for liners and chambers for water

 

[Foketry]

the mold with cores to 3D print

 

[Foketry]

the sand mold with cores sand cured by CO2, ready to pour

 

[michelko]

Unbelievable, you are very productive.

Michael

 

[Foketry]

The casting of cylinder block is done

 

[Foketry]

the two plastic half-molds, are 4 pieces glued because my printer is not large enough

 

[awake]

Great work!

 

[Foketry]

the cylinder block during processing

 

[Foketry]

All over

 

[Foketry]

the cylinder liners project , bore 26 mm with a seat for OR
material : gray cast iron bar GG25 ( EN-GJL-250 )

 

[Foketry]

cylinder turning from gray cast iron bar

 

[Foketry]

8 finished cylinders and 2 rejects

 

[Foketry]

the cylinder liners installed

 

[Foketry]

The composite crankshaft
The connecting rod is mounted on a needle bearing which turns on a hardened pin assembled with interference on 2 flywheels
The 2 flywheels are assembled together with 4 hardened pins and a central screw and rotate on 2 bearings 6003, the whole crankshaft is supported by 9 bearings 6003

 

[Foketry]

the firing order is unusual for a straight 8-cylinder, but this was the standard Bugatti

 

[Foketry]

Flywheels
I left 1 mm allowance on diameter for bearing to grind the complete crankshaft once assembled

 

[Foketry]