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

[Foketry]

After lapping the test with manual vacuum pump, the pressure gauge must go from 25 to 5 in 30 seconds or more , if less lapping again

 

[Foketry]

Valve assembly.
Each valve must have the right clearance under the cam, 0.1-0.2 mm
To achieve this clearance each tappet must be adapted to the valve, by turning the internal thickness

 

[Willyb]

Hello Foketry

You like machining the tappets instead of using shims, Bucket Shims I think they call them? What Aluminum do you use for your Castings? I also like the Casting method as the machining goes faster, especially if you have alot of mass to deal with. Now before everyone puts their hand up, if you take into account your time spent drawing CAD, developing CAM, 3D printing Molds and Cores, finishing the Molds and Cores, and finally Casting, it certainly is NOT faster. I think the biggest reason I like the Casting method, is that your time is split up between different disciplines. Sitting in front of a Computer, watching a 3D Printer and finally burning your fingers and finally machining your Castings. But it's all so much fun.

Totally enjoying your build. Please keep up the great work.

Cheers
Willy

 

[Foketry]

Hello Foketry

You like machining the tappets instead of using shims, Bucket Shims I think they call them? What Aluminum do you use for your Castings? I also like the Casting method as the machining goes faster, especially if you have alot of mass to deal with. Now before everyone puts their hand up, if you take into account your time spent drawing CAD, developing CAM, 3D printing Molds and Cores, finishing the Molds and Cores, and finally Casting, it certainly is NOT faster. I think the biggest reason I like the Casting method, is that your time is split up between different disciplines. Sitting in front of a Computer, watching a 3D Printer and finally burning your fingers and finally machining your Castings. But it's all so much fun.

Totally enjoying your build. Please keep up the great work.

Cheers
Willy

Hi Willyb
I agree with you, it is not faster but it gives great satisfaction
When you remove and clean an aluminum casting from the sand and see the object you thought, designed, printed and cast it is a great happiness.
If you get an engine from an aluminum block, like all the models I've made so far, you have to take into account the time and difficulty to find the correct size aluminum block. Many times you have to start from a round bar to get a cube
For castings I use aluminum ALSi9Cu (EN46400) generally used in the automotive industry, it is also possible to harden it. I have also tried to melt aluminum scrap, but the results are not always good
The costs to make a small foundry yourself are low and in about 15 minutes you can get the molten aluminum

Cheers to you

 

[Foketry]

aluminum casting covers
this engine has 4 covers, 2 in front, 2 in back
In this photo, from Bugatti museum in France, the arrows indicate 2 covers

 

[Foketry]

cover designs and Bugatti logo

 

[Foketry]

Aluminium castings from 3D printed mold

 

[Foketry]

camshafts installed and compression test performed

View attachment 119336

View attachment 119336

 

[Foketry]

Conical clamping for camshaft gear, to carry out the cams timing

 

[michelko]

Yeah that is realy cool stuff. Can´t wait to hear it running

 

[leerkracht]

Wonderful work
one remark , don't forget to harden the camshaft lobes , otherwise you will get a lot of wear and tear very quickly and all the debris will end up in your crankcase and oil with the known consequences.also use hardened ( Stubbsteel ) and polished cam follewers
it takes less time to harden the cams than having to dismantle and clean everything after a few minutes of running the engine and make a new hardened camshaft.

 

[Foketry]

.

 

[Foketry]

Wonderful work
one remark , don't forget to harden the camshaft lobes , otherwise you will get a lot of wear and tear very quickly and all the debris will end up in your crankcase and oil with the known consequences.also use hardened ( Stubbsteel ) and polished cam follewers
it takes less time to harden the cams than having to dismantle and clean everything after a few minutes of running the engine and make a new hardened camshaft.

Of course yes, I built the cams with material suitable for hardening, I will do it when I am sure that everything is correct.
Another thing I have to do is a small hole on the tappeto to facilitate exit of the oil that accumulates inside

 

[Foketry]

Intake manifold
To feed 8 cylinders through the carburetor I designed a manifold in which the distances were the same for each cylinder
2 channels depart from the carburetor (yellow part), the first reaches the center of the first 4 cylinders, the second reaches the center of the second 4 cylinders
Then ,with equal distance each cylinder is fed from the center

 

[Foketry]

I printed the PLA model (the piece on the right is a part of the distributor, not part of the manifold )

 

[Foketry]

aluminum castings

 

[Foketry]

Perforated and milled inlet manifold

 

[Foketry]

Intake manifold assembled to the engine
the holes at the ends still need to be plugged
I will make the first attempts to start the engine without a blower ,at the moment everything is provisional, it is just an assembly test
Even the Allen screws had to be replaced, in 1930 hex screws were used

 

[Foketry]

Water pump
the pump is connected to the timing gears through a pair of bevel gears , as shown in this photo from Bugatti museum

 

[Foketry]

My pump drawings
all parts are made of brass for easy welding, the shaft is stainless steel