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



## Foketry (Apr 5, 2020)

1930 , the Italian Ettore Bugatti built the Bugatti T50 car in France.
It was one of the most beautiful cars built in Europe


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## Foketry (Apr 5, 2020)

The engine is straight 8 cylinder, 4.9 liters with supercharger, overhead camshaft


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## Foketry (Apr 5, 2020)

I would like to make a replica, scale 1 / 3.3
Why scale 1 / 3.3 ?
Simply because the bore  of the original engine was 86 mm, I would like build a 26 mm bore,  (1.023 inch)


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## johnmcc69 (Apr 5, 2020)

That's going to be a big model but a real beauty of one.
 Looking forward to your build!

 John


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## Rod Cole (Apr 5, 2020)

Is there, or will there be scaled down blue-prints for this idea. I think if there were they would sell easy. Such a good looking engine, with an amazing history!!!!!


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## petertha (Apr 5, 2020)

Going to be good Foketry! What have you got for documentation right now?

I thought I recall seeing a model engine, not sure if it was this refernce or not


			Bugatti photo server - Misc Stuff/IMG 0739


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## lohring (Apr 6, 2020)

It's been done in 1/4 scale.  See Bugatti Typ 50 1/4 Scale model

Lohring Miller


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## Rod Cole (Apr 6, 2020)

Lohring that's looking like a very nice job!!!


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## Foketry (Apr 7, 2020)

petertha said:


> Going to be good Foketry! What have you got for documentation right now?
> 
> I thought I recall seeing a model engine, not sure if it was this refernce or not
> 
> ...



Thank you for your suggestion
For reference with size I bought on Ebay an old italian kit 1:8 scale, I read that it is one of the most faithful reproductions
Copy of original designs can also be purchased, but each design costs hundreds of dollars.
I am also in contact with Michelko who has already built this model and has given me some dimensions and photos

plastic Pocher reproduction


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## Foketry (Apr 7, 2020)

lohring said:


> It's been done in 1/4 scale.  See Bugatti Typ 50 1/4 Scale model
> 
> Lohring Miller



I know these posts very well, I am in contact with Michelko who helped me develop this project


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## Foketry (Apr 7, 2020)

my project, not yet complete







Blower


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## Foketry (Apr 7, 2020)

the head


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## michelko (Apr 7, 2020)

I will follow this build thread for sure. The link above Shows my Bugatti interpretation also based on the Pocher model. 

Unfortenatly i had some problems with the engine. At forst i thought th eplugs where the problem. in the mean time i think it was leaking valves. I am still in the process of reworking the valves. Hope i can start it again soon.

Jules, please keep on posting your progress.

Michael


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## awake (Apr 7, 2020)

Foketry said:


> the head
> 
> View attachment 115070



Looks like you've gotten ahead in this project ...

 Sorry, couldn't resist the awful pun!


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## michelko (Apr 7, 2020)

Hi Jules,
do plan to use an oilpump for lubrication of the cams? If yes have you thought About the backflow to the sump?

Michael


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## Foketry (Apr 7, 2020)

michelko said:


> Hi Jules,
> do plan to use an oilpump for lubrication of the cams? If yes have you thought About the backflow to the sump?
> 
> Michael



yes ,I have already bought and tested a small gerotor Chinese pump , now I'm looking for 3 mm diameter oil seal for valves, in order to avoid that the oil is sucked into the combustion chamber through the valve stem.
Everything is in my mind, but I still have to draw


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## Rod Cole (Apr 7, 2020)

Love a good pun!!!!!!!!!!!!!!!!


awake said:


> Looks like you've gotten ahead in this project ...


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## Foketry (Apr 7, 2020)

michelko said:


> I will follow this build thread for sure. The link above Shows my Bugatti interpretation also based on the Pocher model.
> 
> Unfortenatly i had some problems with the engine. At forst i thought th eplugs where the problem. in the mean time i think it was leaking valves. I am still in the process of reworking the valves. Hope i can start it again soon.
> 
> ...



about the plugs I suggest you use commercial ones with the short thread 1/4 32 or CM6 M10x1 , in the photo of the head at the post #12  you can see the deep holes for  plugs

regarding leakage of  valves, I use a small manual vacuum pump to do the test after grinding and I make a really small chamfer, max 0.1mm in the edge of the valve cage 

I hope this is useful


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## awake (Apr 7, 2020)

Rod Cole said:


> Love a *good* pun!!!!!!!!!!!!!!!!



Thanks, but what about the one I made?


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## michelko (Apr 8, 2020)

I also purchased this vacuum pump to test the valves after the repair. For the repair i made a cutter with a Pilot pin.

The comercial plugs are t pricy so i decided to make my own. Besides this ist a Hobby a making parts is fun. The plugs worked nice but after some tme they get wet and stoped firing.

Some time i noticed the valves leaking. i bet the maine Problem where the valves.
Still have a new set plugs that i will test when the engine is together again.
That is an cute little pump!!
I did mine as gearpump. Because the hole crank has ball/needlebearings the pump is only used to feed some oil into the head and lubricate the cam and followers.

Michael


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## Foketry (Apr 8, 2020)

michelko said:


> I also purchased this vacuum pump to test the valves after the repair. For the repair i made a cutter with a Pilot pin.
> 
> The comercial plugs are t pricy so i decided to make my own. Besides this ist a Hobby a making parts is fun. The plugs worked nice but after some tme they get wet and stoped firing.
> 
> ...



you could check the compression for each cylinder to understand where the leaks are ,valves or piston rings
To do the compression test, better use a small pressure gauge with a one-way valve (e.g.  bicycle tire valve) limiting the internal volume as much as possible so as not to increase the volume of the combustion chamber and get an incorrect value.


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## Foketry (Apr 9, 2020)

the crankcase to support the crankshaft


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## Foketry (Apr 9, 2020)

3D pattern , printed in 2 parts , glued ,painted with primer and then sanded, my printer allows max 200x200x200 mm (8inch)
I had to finish some residues of PLA filament , note the different colors


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## Foketry (Apr 9, 2020)

aluminium casting whit greensand on bottom and petrobond sand on top
















My LPG  foundry


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## Foketry (Apr 9, 2020)

the crankcase ready for machining


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## petertha (Apr 9, 2020)

Wow, you work fast. And that is an impressive overall size now that we see part relative to a hand. Going to be good!


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## stevehuckss396 (Apr 9, 2020)

Looks fimilar. I started a 1/4 scale 50T about 15 years ago. It was my first engine attempt. Finishing it would require a total re-design because it was a terrible design to begin with.  I think my crankshaft was 17 pieces. Wish I was smarter back then. Makes me happy to see you are doing a way better job.


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## sition (Apr 9, 2020)

ñice


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## Foketry (Apr 10, 2020)

stevehuckss396 said:


> Looks fimilar. I started a 1/4 scale 50T about 15 years ago. It was my first engine attempt. Finishing it would require a total re-design because it was a terrible design to begin with.  I think my crankshaft was 17 pieces. Wish I was smarter back then. Makes me happy to see you are doing a way better job.
> 
> View attachment 115141
> 
> ...



Your T50 looks very nice, I hope mine becomes the same
I also designed the crankshaft in several parts, I want to mount only bearings, not bronze bushings
In yours there are 2 distributors, I would like to put only one , equal to the Demon V8
To lubricate valves and camshaft have you installed a pump?


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## Foketry (Apr 11, 2020)

Milling of  motor base, glued on wood because it is difficult to fix it in the vice without deformation and ensure good support


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## Foketry (Apr 11, 2020)

the crankcase nearly finished


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## Foketry (Apr 11, 2020)

now I have to make supports for crankshaft bearing (yellow color)
3D mold , casting and processing


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## Jan Dressler (Apr 13, 2020)

Hello!

As a long-time lurker here, I just had to post finally when I saw another Bugatti project in the works...
Really great so far, nice to see the CAD pictures, and waiting for further progress!

I am working on a Type 35 engine myself, bit older and much smaller at 2 or 2.3 liters. In my scale of 1:3 its a 20 mm bore. 
Working on that (on and off) since 2013, collecting drawings, books, pictures, visiting museums, annular Molsheim festival... 

I also 3D-printed the parts I finished in CAD so far, but not yet with the intention of casting (that will come later), just to see if everything comes together as planned - and of course, to have some nice plastic model standing around to remind me to continue work on it.

Good luck with your project, checking for news daily!

Greetings, Jan


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## Doug Cygan (Apr 14, 2020)

Jan Dressler said:


> Hello!
> 
> As a long-time lurker here, I just had to post finally when I saw another Bugatti project in the works...
> Really great so far, nice to see the CAD pictures, and waiting for further progress!
> ...


Hi Jan, Superb workmanship on both the 3D design and the 3D print. I too am working on designing the same engine, but in 1/4 scale. However, I'm thinking that 1/3 might be a better option to make an operable internal combustion engine. I've designed and printed the oil sump, and crankcase. There's so much more to design and then print. I've also 3D designed and mostly built a Bugatti Type 50 engine. My intention is to cast the various pieces in the types of metal that the original engines are made from. Cast iron pieces will be pushing my small shop foundry to its limits.


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## Jan Dressler (Apr 14, 2020)

Hi Doug, and thank you for the kind words!

Yes, with 1/4, things might become a bit tiny... 3 valves with a 15 mm bore - also the fasteners, a lot of M6 and M9 in this engine, which scale a bit better in 1/3.
Design- and "re-engineering"-wise, things get interesting when you come to cylinders and cambox, if you want to do it "scale" and not just outer appearance.
Casting will be a jump into cold for myself, since I have no practical experience. Need to start with simple things and work my way up  

But enough derailing of this thread, waiting for progress on that T50


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## Foketry (Apr 14, 2020)

Jan Dressler said:


> Hi Doug, and thank you for the kind words!
> 
> Yes, with 1/4, things might become a bit tiny... 3 valves with a 15 mm bore - also the fasteners, a lot of M6 and M9 in this engine, which scale a bit better in 1/3.
> Design- and "re-engineering"-wise, things get interesting when you come to cylinders and cambox, if you want to do it "scale" and not just outer appearance.
> ...



Great guys , now I understand I'm not alone in sharing admiration for Bugatti engine , here we are at least 5.
Unfortunately  I was not able to visit the Molseim museum, I had planned a weekend in February in that museum but Coronavirus blocked everything.
I purchased a plastic model of the T50 engine to measure the dimensions and make the drawings.
About the aluminum castings , I started a few months ago to do the first experiments, I suggest to see the Myfordboy videos on Yuotube, they taught me a lot .


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## Foketry (Apr 15, 2020)

bearing support for crankshaft , 9 pieces


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## Foketry (Apr 15, 2020)

after the drawing, the aluminum castings, not perfect, but acceptable


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## Foketry (Apr 15, 2020)

the bearing supports machined and assembled
after assembly a light reaming with a reamer to ensure alignment


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## Doug Cygan (Apr 15, 2020)

Foketry said:


> Great guys , now I understand I'm not alone in sharing admiration for Bugatti engine , here we are at least 5.
> Unfortunately  I was not able to visit the Molseim museum, I had planned a weekend in February in that museum but Coronavirus blocked everything.
> I purchased a plastic model of the T50 engine to measure the dimensions and make the drawings.
> About the aluminum castings , I started a few months ago to do the first experiments, I suggest to see the Myfordboy videos on Yuotube, they taught me a lot .


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.


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## Foketry (Apr 15, 2020)

Doug Cygan said:


> 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


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## awake (Apr 15, 2020)

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


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## Doug Cygan (Apr 15, 2020)

Foketry said:


> 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.
> ...



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.


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## Foketry (Apr 17, 2020)

The cylinder block for  liners and chambers for water


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## Foketry (Apr 17, 2020)

the mold with cores to 3D print


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## Foketry (Apr 17, 2020)

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


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## michelko (Apr 17, 2020)

Unbelievable, you are very productive.

Michael


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## Foketry (Apr 18, 2020)

The casting of  cylinder block is done


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## Foketry (Apr 18, 2020)

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


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## awake (Apr 18, 2020)

Great work!


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## Foketry (Apr 23, 2020)

the cylinder block during processing


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## Foketry (Apr 23, 2020)

All over


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## Foketry (Apr 29, 2020)

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


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## Foketry (Apr 29, 2020)

cylinder turning from gray cast iron bar


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## Foketry (Apr 29, 2020)

8 finished cylinders and 2 rejects


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## Foketry (Apr 29, 2020)

the cylinder liners installed


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## Foketry (May 14, 2020)

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


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## Foketry (May 14, 2020)

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


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## Foketry (May 14, 2020)

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


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## Foketry (May 14, 2020)




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## Foketry (May 14, 2020)

finished flywheels
the hole for the hardened pin is 0.02 mm smaller than the pin


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## Foketry (May 14, 2020)

machining of hardened pins, obtained from commercial pins and beveled 30 degrees for assembly by 6 Tons press


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## Peter Twissell (May 14, 2020)

The last photo in post #60 shows a milled face on the crank web. What was that operation?


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## Foketry (May 14, 2020)

Peter Twissell said:


> The last photo in post #60 shows a milled face on the crank web. What was that operation?



to ensure the perpendicularity between plane and 4 holes, I tried to mill the plane before making the holes, but it was a test with poor results.
I preferred to align the turned piece in the vice, check with the dial gauge and drill the holes


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## michelko (May 15, 2020)

Hi Jules,
you are making great Progress. With that Velocity the engine should run in a pair of weeks.

Michael


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## michelko (May 15, 2020)

Your Setup with the four Pins is very interesting. It should give a very precise allignement and the screw is only stressed be draw. I used for this connection 4 m3 screws. with no pin the allignement is made with the race of the ball bearing.
The screws are stressed be drwa and maybee also by shearing. So i believe your way is the better solution.

Michael


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## Foketry (May 15, 2020)

michelko said:


> Your Setup with the four Pins is very interesting. It should give a very precise allignement and the screw is only stressed be draw. I used for this connection 4 m3 screws. with no pin the allignement is made with the race of the ball bearing.
> The screws are stressed be drwa and maybee also by shearing. So i believe your way is the better solution.
> 
> Michael


my solution is 4 pins dia 3 mm and a central M4 screw to guarantee the phase for each cylinder and the transmission of the torque
After  crankshaft  assembly  I will make a grind of bearings seats.


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## Peter Twissell (May 15, 2020)

Nice solution Foketry. This is the same principal typically used to secure flywheels, prop drivers etc. on 'fullsize' engines.
Another option uses hollow dowels with screws through the dowels. This allows both the shear and tensile loads to be reacted at a greater radius from the axis, giving the assembly greater stiffness.


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## Foketry (May 15, 2020)

michelko said:


> Hi Jules,
> you are making great Progress. With that Velocity the engine should run in a pair of weeks.
> 
> Michael


Hi Michel
yes in a pair of weeks , but in the next year


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## Foketry (May 15, 2020)

the complete crankshaft design


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## Foketry (May 15, 2020)

pin pressed into the hole and needle bearing


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## Foketry (May 15, 2020)

one of 8 crank web


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## Foketry (May 15, 2020)

Tool post grinder at work on the lathe


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## Foketry (May 15, 2020)

The complete ground crankshaft

Attach files


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## Foketry (May 15, 2020)

assembled in the engine block


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## johnmcc69 (May 15, 2020)

Looks great!
 How do you dress the grinding wheel to the lathe spindle axis?

 John


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## Foketry (May 15, 2020)

johnmcc69 said:


> Looks great!
> How do you dress the grinding wheel to the lathe spindle axis?
> 
> John


with a dressing diamond fixed on the chuck, as in a grinding machine


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## Foketry (May 22, 2020)

The design of the  rod


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## Foketry (May 22, 2020)

the machined rods, first phase


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## Foketry (May 22, 2020)

Cutting with band saw


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## Foketry (May 22, 2020)

The rods ready for second phase, 2 holes for M4 screws
there are only 7 because one is already installed on the crankshaft


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## stevehuckss396 (May 22, 2020)

Really nice looking rods. Too bad they wont be seen.


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## Peter Twissell (May 23, 2020)

Do you make a finished rod first, before starting on the "serial production"?
I did most parts that way for my radial.
My grandson has a very piston shaped money box, which was my first attempt and taught me to check wall thickness before machining!


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## Foketry (May 24, 2020)

Peter Twissell said:


> Do you make a finished rod first, before starting on the "serial production"?
> I did most parts that way for my radial.
> My grandson has a very piston shaped money box, which was my first attempt and taught me to check wall thickness before machining!



yes , I made 2 finished rods before producing all 8. This is to test the CNC program, assembly on the motor and theoretical compression with a false piston


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## Foketry (May 24, 2020)

The finished  rods


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## Foketry (May 24, 2020)

Milling on the other side


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## Tim1974 (May 25, 2020)

Very nice work I’m enjoying this one


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## Foketry (May 31, 2020)

Today I finished the pistons, wrist pins, bushings for connecting rods and bronze washers for pins


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## Foketry (May 31, 2020)

The wrist pin


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## Foketry (May 31, 2020)

Bronze bushing


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## Foketry (May 31, 2020)

I turned the pistons from aluminum bar 7075 (Ergal)
in the photo the double turned pistons


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## Foketry (May 31, 2020)

internal milling of the double pistons and the pistons separated after milling


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## Foketry (May 31, 2020)

drilling the wrist pin hole


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## Foketry (May 31, 2020)

the finished pistons and their accessories

piston rings are commercial, diameter 26 mm (1,023 inch)

the pins are made of hardened commercial pins, it is not possible to drill inside, only turning at the ends for the required length


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## Peter Twissell (Jun 1, 2020)

What are the brass / bronze washer for?


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## Foketry (Jun 2, 2020)

Peter Twissell said:


> What are the brass / bronze washer for?



Are bronze washers to avoid damaging the liners


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## Peter Twissell (Jun 2, 2020)

Ah - buttons (as I know them).


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## leerkracht (Jun 5, 2020)

Piston  wrist pin
to make piston shafts I use inductively hardened shafts that are available from diameter 3mm (less than 1/8 inch) in inches from 1/4)  the advantage is that the core is still soft, the outside is hardened and ground to h6 tol , is round, straight and cylindrical. to protect the cilinder wall  i used teflon pads
the axes are used in linear motion technology  ( https://www.thn.nl/files/stream/documents/THN-TS06-NL.pdf)
gr


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## Foketry (Jun 7, 2020)

this material is interesting, there‘s no technical information regarding the internal hardness but it seems possible to make longitudinal holes to lighten the wrist pin
I'm looking for it in Italy, thanks for  the suggestion


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## leerkracht (Jun 7, 2020)

piston Wrist pin  extra


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## michelko (Jun 7, 2020)

leerkracht said:


> Piston  wrist pin
> to make piston shafts I use inductively hardened shafts that are available from diameter 3mm (less than 1/8 inch) in inches from 1/4)  the advantage is that the core is still soft, the outside is hardened and ground to h6 tol , is round, straight and cylindrical. to protect the cilinder wall  i used teflon pads
> the axes are used in linear motion technology  ( https://www.thn.nl/files/stream/documents/THN-TS06-NL.pdf)
> gr


Hi i also used these material for my bugatti piston pins.
You can turn them to length with hard alloy inserts,no need to grind.
Michael


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## Foketry (Jun 8, 2020)

michelko said:


> Hi i also used these material for my bugatti piston pins.
> You can turn them to length with hard alloy inserts,no need to grind.
> Michael



Hi Michael
do you buy it in Holland or is there an online seller in Germany?
Is it possible to drill with normal HSS drills?


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## leerkracht (Jun 8, 2020)

Hello 

These inductif hardened  rods can be drilled with normal HSS drils  ( i prefer HSS Co 5%) for lengtening i prefer  grinding








						THN | Tel: 053 - 432 34 46 | E-mail: [email protected]


✓THN is sinds de oprichting in 1940 gevestigd aan de Hendrik ter Kuilestraat 30, 7547 BD in Enschede. ✓Tel: 053 - 432 34 46.




					www.thn.nl


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## michelko (Jun 8, 2020)

Hi Lules,
as leerkracht mentioned These rods can be drilled with hss. Thea just have an hardened survace aprox 05-1mm thick Maybe less.

Here i ordered mine if i remeber correct. You can get them in many numbers but not smaler than 3 or  4mm i guess.












						Linearwelle, Präzisionswelle  Ø  4 mm, gehärtet, Länge frei wählbar!  | eBay
					

Entdecken Sie Linearwelle, Präzisionswelle  Ø  4 mm, gehärtet, Länge frei wählbar! in der großen Auswahl bei eBay. Kostenlose Lieferung für viele Artikel!



					www.ebay.de


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## michelko (Jun 8, 2020)

This is another source for the hardenend and Ground rods.






						Precision Shaft Steel Material CF53, Hardened and Ground | MÄDLER Webshop
					

Precision Shaft Steel Material CF53, Hardened and Ground, Material: Steel 1.1213 (CF53). Hardness min. 59 HRC.




					www.maedler.de
				




I usealy cut them Rough to length with an anglegrinder and then use a Carbide insert for turning to the exact length.

Michael


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## leerkracht (Jun 10, 2020)

look at this site  lots of information





						Piston Rod Predictor
					






					steelnavigator.ovako.com
				








						Heat Treatment Guide
					






					steelnavigator.ovako.com
				








						Start
					






					steelnavigator.ovako.com


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## Foketry (Jun 12, 2020)

michelko said:


> This is another source for the hardenend and Ground rods.
> 
> 
> 
> ...


Hi Michael 
I found the same material from my usual supplier, near my house, I thought it was completely hardened and hard, but instead it is possible to drill in the center with HSS
Thank you for your suggestion


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## Foketry (Jun 12, 2020)

leerkracht said:


> look at this site  lots of information
> 
> 
> 
> ...




Thank you for your suggestion


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## Foketry (Jun 13, 2020)

Timing  gearbox design and construction

Photo of the original engine


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## Foketry (Jun 13, 2020)

Timing gearbox design












The cover with  housings for ball bearings






the box with relative housings


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## Foketry (Jun 13, 2020)

Top cover


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## Foketry (Jun 13, 2020)

the plastic molds to be finished and painted with primer and top coat


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## Foketry (Jun 13, 2020)

The mockup for test distance of the gears , each gear is supported by 2 bearings


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## Foketry (Jun 14, 2020)

The 4 castings for timing gearbox


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## Foketry (Jun 16, 2020)

sanded and painted molds


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## Foketry (Jun 16, 2020)

Timing gearbox with gears


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## Foketry (Jun 16, 2020)

assembled timing gearbox


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## michelko (Jun 16, 2020)

This is a cool idea withe the two side ball bearings.
 Michael


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## michelko (Jun 17, 2020)

show me yours and i willl show you mine


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## Foketry (Jun 25, 2020)

Camshaft project , there are a double overhead camshaft
The square profile on each cam has the function of facilitating the timing, the hole is for spring pin
The shaft is 8 mm supported by 5 needle  bearings


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## Foketry (Jun 25, 2020)

cam drawing and the first 2 milled cams, before hardening


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## michelko (Jun 26, 2020)

Foketry said:


> cam drawing and the first 2 milled cams, before hardening
> 
> View attachment 117413
> 
> ...


Those are great looking cams. Good idea with the square.
I used a kind of fork that matched the lobe of the cams to adjust the cams. Your solution looks way more accurate.
How do you machine the cams? Any pictures from the setup?

Regards Michael


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## michelko (Jun 26, 2020)

Hi lules 
do you use a hardened shaft? i belive the needle bearing will wear an unhardend shaft quickly.

Regards Michael


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## awake (Jun 26, 2020)

Foketry said:


> Camshaft project , there are a double overhead camshaft
> The square profile on each cam has the function of facilitating the timing, the hole is for spring pin
> The shaft is 8 mm supported by 5 needle  bearings
> 
> ...



I would think you would need the gear teeth to go all the way around ...


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## Foketry (Jun 27, 2020)

michelko said:


> Those are great looking cams. Good idea with the square.
> I used a kind of fork that matched the lobe of the cams to adjust the cams. Your solution looks way more accurate.
> How do you machine the cams? Any pictures from the setup?
> 
> Regards Michael



Hi Michael 
here is my setup, Now I am milling the intake cams
They are obtained from ground bar, C45 steel 
The most suitable steel would be 115CrV3, which I purchase from GHW modelbau in Germany, in Italy I cannot buy small quantities of this steel, only tons , this steel is easy to harden with high hardness in water


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## Foketry (Jun 27, 2020)

awake said:


> I would think you would need the gear teeth to go all the way around ...



yes, correct, better to have all  teeth around


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## Foketry (Jun 27, 2020)

In the end the result should be this , but with all the teeth around


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## Foketry (Jul 1, 2020)

the camshafts are almost complete, the timing is missing, it will be done in the end


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## Foketry (Jul 1, 2020)

the head is made up of 3 parts, 2 side boxes carrying camshafts and one central part with the spark plugs, valves and combustion chambers
Also the head of the original engine is in 3 parts


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## Foketry (Jul 1, 2020)

my plastic model painted and smoothed and aluminum casting


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## Foketry (Jul 1, 2020)

After milling the first check with camshaft







on the left the central part of the head with the seats for the spark plugs and the water chamber for cooling


----------



## Foketry (Jul 1, 2020)




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## Foketry (Jul 1, 2020)

Assembly test


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## johnmcc69 (Jul 1, 2020)

Nice work!

 John


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## Foketry (Jul 16, 2020)

Small progress after 2 weeks of vacation :
Bushing cap for camshaft


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## Foketry (Jul 16, 2020)

Assembled caps bushes


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## Foketry (Jul 16, 2020)

The original engine, here I can see the camshaft cover and the fixing brackets


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## Foketry (Jul 16, 2020)

Drawing of  fixing bracket to be 3D printed to make the casting mold


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## Foketry (Jul 16, 2020)

Camshaft cover assembled with only 3 brackets of 5, 2 are casting waste, to be redone
Everything will have to be sandblasted and finished


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## Foketry (Jul 21, 2020)

head and overhead valves
it is the first time that I build an engine with overhead valves and I do a first test with a single valve


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## Foketry (Jul 21, 2020)

Overhead camshaft and holes for valve cages

I prefer to slide the tappet on a hardened steel bush instead of aluminum, this needs lubrication
To prevent the lubricant  being sucked into the cylinder, I have provided an oil seal


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## Foketry (Jul 21, 2020)

The valve


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## Foketry (Jul 21, 2020)

drilling holes for valves


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## Foketry (Jul 21, 2020)

first test of a complete valve , after a couple of hours of setup, everything works


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## mnay (Jul 21, 2020)

Amazing work.  I am just learning to use my 3d printer.  Are you printing PLA?  What do you use to smooth them for use as patterns?
Also do you design the draft angle on the patterns or are they smooth enough to remove without pulling the sand with them?
thanks for the inspiring build log.
Mike in Salt Lake City


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## Badhippie (Jul 22, 2020)

May I ask how you plan on keeping the cams from walking is there a cam button on one end or are you using a thrust bearing on one of the camshaft caps??? Very nice work can’t wait to see a video of it running Thanks 
Tom


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## Foketry (Jul 23, 2020)

mnay said:


> Amazing work.  I am just learning to use my 3d printer.  Are you printing PLA?  What do you use to smooth them for use as patterns?
> Also do you design the draft angle on the patterns or are they smooth enough to remove without pulling the sand with them?
> thanks for the inspiring build log.
> Mike in Salt Lake City



Hi Mnay
for patterns I draw a draft angle of 2.5 / 3 degrees and use a layer of 0.2 mm
Then I paint the model with a thick primer ( polyesters) , smooth the surface with sandpaper and repaint with topcoat
This is the fastest method I know.
You  could also avoid the paint and sand directly on PLA, but the final result is aesthetically lower and the footprint in the foundry sand could be damaged while removing the pattern

Salt Lake City is famous in Italy for Garage Monkey, does it really exist or is it just a television fiction?


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## Foketry (Jul 23, 2020)

Badhippie said:


> May I ask how you plan on keeping the cams from walking is there a cam button on one end or are you using a thrust bearing on one of the camshaft caps??? Very nice work can’t wait to see a video of it running Thanks
> Tom



Hi Badhippie
The cams will be fixed to the shaft by a sprig pin or conical pin
To axially lock the shaft, I will place 2 bushings on the ends that rest on the side of the final bronze bushings and cams
In a couple of weeks you will see the camshafts fully assembled , if everything goes without errors ....


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## mnay (Jul 24, 2020)

Foketry,
Thank you the information on 3d pattern making.
Sorry but I have not heard of Garage Monkey.  I will have to google
Mike


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## stevehuckss396 (Jul 24, 2020)

Are you talking about "Gas Monkey Garage"?


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## Foketry (Jul 26, 2020)

stevehuckss396 said:


> Are you talking about "Gas Monkey Garage"?



yes, I'm talking about Gas Monkey garage, but I remembered badly, this is in Dallas, Salt lake city garage instead is in Salt Lake city, both have done a TV series, seen in Italy


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## stevehuckss396 (Jul 26, 2020)

I think gas monkey is in texas.


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## Foketry (Jul 29, 2020)

machining of the intake head


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## Foketry (Jul 29, 2020)

drilling and reaming holes for intake cages
the 8 exaust cages are already assembled


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## Foketry (Jul 29, 2020)

overhead valve design with 4 mm oil seal


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## Foketry (Aug 1, 2020)

valve spring retainer  turning


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## Foketry (Aug 1, 2020)

the complete kit of 16 valves, 8 valve cages already assembled in the heads


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## thefishhunter (Aug 1, 2020)

Beautiful stuff


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## Foketry (Sep 1, 2020)

I installed the cages using the hammer and a tool to avoid deformation, also putting Loctite 620 which resists high temperatures.
The diameter of the cages is increased 0.01 / 0.02mm with respect to the housing hole
After installation I made a very small  chamfer (0,1/0,2 mm ) in cages with this small tool that is driven through the hole.


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## Foketry (Sep 1, 2020)

After the bevel I lapped all 16 valves, 3/4 days of work , is very boring
I puts the valve  into the cage with some lapping compound and then twirls it by  special tool and finally by hands with very fine lapping compound


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## Foketry (Sep 1, 2020)

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


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## Foketry (Sep 6, 2020)

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


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## Willyb (Sep 8, 2020)

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


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## Foketry (Sep 11, 2020)

Willyb said:


> 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.
> 
> ...




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


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## Foketry (Sep 11, 2020)

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


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## Foketry (Sep 11, 2020)

cover designs and Bugatti logo


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## Foketry (Sep 11, 2020)

Aluminium castings from 3D printed mold


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## Foketry (Sep 14, 2020)

camshafts installed and compression test performed

View attachment 119336



View attachment 119336


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## Foketry (Sep 14, 2020)

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


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## michelko (Sep 14, 2020)

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


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## leerkracht (Sep 15, 2020)

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.


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## Foketry (Sep 16, 2020)

.


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## Foketry (Sep 16, 2020)

leerkracht said:


> 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


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## Foketry (Sep 23, 2020)

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


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## Foketry (Sep 23, 2020)

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


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## Foketry (Sep 23, 2020)

aluminum castings


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## Foketry (Sep 23, 2020)

Perforated and milled inlet manifold


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## Foketry (Sep 23, 2020)

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


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## Foketry (Oct 1, 2020)

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


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## Foketry (Oct 1, 2020)

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


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## Foketry (Oct 1, 2020)

The casting molds, 3D printed


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## Foketry (Oct 1, 2020)

Brass castings
Brass melts at 1015 celsius degrees , I was not sure if my gas furnace could reach this temperature, until now I have only melted aluminum (650 °),but I haven't had any problems, it's just a matter of time.


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## Foketry (Oct 1, 2020)

All pump parts , ready for assembly


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## Foketry (Oct 1, 2020)

Pump assembled, ready for testing


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## Foketry (Oct 1, 2020)

Final test with water, 1200 rpm with  cordless drill


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## michelko (Oct 2, 2020)

Awesome work!! got mine running again after the valve job. 
Runs better then ever. 
Cant´wait to see yours running.

I did my pump from aluminium and glued the two halves together with jb Weld.
Only a small grey seam is visible.

Have you made the pistons yet? do plan to make oil control rings?
I have some smoking with mine and i just used two compression rings and one grove  with holes. 

Regards Michael


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## Foketry (Oct 2, 2020)

michelko said:


> Awesome work!! got mine running again after the valve job.
> Runs better then ever.
> Cant´wait to see yours running.
> 
> ...




Great job and nice engine, i hope mine works like yours ...
the pistons are already assembled in the engine, I only put 2 piston rings, diameter 26 mm that I found commercial, spare parts for a brush cutter. 
My suggestion, If you want to eliminate the smoke, lower the oil level, even a low oil level is enough to lubricate everything, maybe your engine won't do more than 10 / 15,000 km per month...

A question, how did you build the conical water return pipe?  machined from solid or wrapped in a brass sheet ?

thank you very much


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## michelko (Oct 2, 2020)

The pipe is made out of several pieces with different diameter joint by soldering. Then the joints where filed/ground down on the lathe.
The piece is almost cylindrical but looks like conical.


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## Foketry (Oct 2, 2020)

michelko said:


> The pipe is made out of several pieces with different diameter joint by soldering. Then the joints where filed/ground down on the lathe.
> The piece is almost cylindrical but looks like conical.



If you allow, I have another question:
the carburetor is in the center of the 8 cylinders, between cylinder 4 and 5.
  This means that the distance between the carburetor and cylinder 1 is different from  distance between carburetor and cylinder 4, did this cause problems or everything are ok?


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## michelko (Oct 3, 2020)

Cant say its a problem.
You always have different length for the several cylinders unless you use 8 carbs.
A big issue where the bad sealing of the valves. After redoing that the motor runs just nice.
Another issue was oiling up to the distributor. Some oil found its way into the cap.
I will redo the setup  with a rubber seal and also a different runner.


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## lathe nut (Oct 4, 2020)

WOW, that is so cool and cute, your good and it shows, that is so far above my head, I understand engine and work on them but to machine those parts and get it to run like that, it won't happen in my shop, thanks for sharing, Joe


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## Foketry (Oct 11, 2020)

The distributor, I tried to make it similar to the original Scintilla (Bosch)


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## Foketry (Oct 11, 2020)

My distributor, built in Plexiglass, 3 layers glued together ,transparent to facilitate timing
While the rotor rotates I can see if there are sparks jumping into the wrong electrodes

The central electrode was obtained by turning from a brush for an electric motor





Graphite central electrode with spring to keep it always in contact with the rotor central electrode


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## Foketry (Oct 11, 2020)

8 magnets 3 mm diameter for Hall sensor


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## Foketry (Oct 11, 2020)

the distributor being tested


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## Foketry (Oct 11, 2020)

the camshafts with hardened cam and bevel gear to transmit rotation to the distributor










the blue on the teeth of the gear is to verify the contact of the teeth, it must be towards the initial part of the tooth
after running the contact will extend along the entire tooth


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## michelko (Oct 12, 2020)

Awesome


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## michelko (Oct 12, 2020)

michelko said:


> Awesome


What diameter is the dizzy cap?

Michael


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## Foketry (Oct 12, 2020)

michelko said:


> What diameter is the dizzy cap?


The cap  is 31mm in external diameter , very important is the distance between the electrodes, not less than 8-9mm


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## Foketry (Oct 27, 2020)

Oil sump
the real engine


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## Foketry (Oct 27, 2020)

My drawing , oil sump


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## Foketry (Oct 27, 2020)

My aluminum casting


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## Foketry (Oct 27, 2020)

engine fixing brackets to be screwed to the oil sump






3D printed semi model and casting , 4 pieces are required


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## Foketry (Nov 5, 2020)

Trial assembly to see if everything goes in the correct position


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## michelko (Nov 5, 2020)

You are getting closer . Looks beautyfull

Michael


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## Foketry (Nov 22, 2020)

I finished the 4 side covers with the Bugatti logo and the circular satin finish , as original engine
In the 2 large covers the logo is directly cast, in the 2 small ones the logo is milled with a 0.5 mm  end mill


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## Foketry (Nov 22, 2020)

After doing the project I printed them with a PLA 3D printer, imprinted in the red sand (Petrobond) and poured the molten aluminum


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## Foketry (Nov 22, 2020)

The processing of circular satin finishing with a rubber wheel mounted on an electrospindle, 7000 rpm and a few drops of WD40 on my CNC milling machine.


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## michelko (Nov 23, 2020)

Those plates came out realy nice

Michael


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## Foketry (Nov 24, 2020)

michelko said:


> Those plates came out realy nice
> 
> Michael


Thanks for your advice


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## Foketry (Nov 24, 2020)

The radiator fan with its pulleys and flat belt


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## Foketry (Nov 24, 2020)

To make the fan I used the new printer for liquid resin that arrived a few days ago, this printer does not leave the mark of the layers like filament printers, moreover it is much more defined and precise, the layers thickness is 0.05 mm (0,0019 inc )
This is very useful for making foundry patterns, no need to sand and paint
You can appreciate the difference in the photo of the 2 fans, one made with a filament  printer, the other with a resin printer


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## Foketry (Nov 24, 2020)

To put 2 bearings and an oil seal in the drive pulley without increasing the thickness I adopted this solution, the pulley is driven by the crankshaft  and a transverse pin.


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## FTX (Nov 25, 2020)

Hello 

Great job. Very impressive.

Ftx


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## gbritnell (Nov 25, 2020)

Still following along. Very nice work!


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## Foketry (Nov 30, 2020)

I have improved the efficiency of the water pump, I was not completely satisfied with the previous test

the previous test


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## Foketry (Nov 30, 2020)

the  today test


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## Foketry (Nov 30, 2020)

I replaced the old brass impeller with a new plastic one, printed with the new 3D printer and also removed the cutwater


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## Foketry (Nov 30, 2020)

The pump is connected to the distribution gearbox by bevel gears


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## OllyM (Dec 1, 2020)

That is beautiful work, absolutely superb! I've been using a resin 3d printer for mechanical parts (gears, brackets, mounting frames etc). One thing to bear in mind is that most of the resins are very brittle, very much like acrylic. I've used purpose made engineering resins have much better mechanical properties, although they aren't cheap. Here's one supplier that I've used:
Formfutura Engineering Resins

The clear type is less brittle, the grey type is very very strong, and heat resistant.

Cheers,

Oliver


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## michelko (Dec 1, 2020)

Hi Jules,
those 3d prints looks awesome. I think i also need a printer soon.
Your pump makes some good flow (maybee to much?) , what rpm is it in the photo?
Here is my pump impeller, with idle aprox 1500 rpm it makes just enough flow that i can see the coolant slightly flow out of the returnpipe.
With an pc fan on the radiator i can keep the engine temp at 60-70 degree.
When will we hear it running?

Regards Michael

P.S: Just started machining the holt castings you gave me.


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## Foketry (Dec 1, 2020)

michelko said:


> Hi Jules,
> those 3d prints looks awesome. I think i also need a printer soon.
> Your pump makes some good flow (maybee to much?) , what rpm is it in the photo?
> Here is my pump impeller, with idle aprox 1500 rpm it makes just enough flow that i can see the coolant slightly flow out of the returnpipe.
> ...



Hi Michael
My cordless drill rotates approx at 1100 rpm without load, I think 950-1000 rpm during the test, if the flow of water is too much, I can reduce it, but I assure you it is never too much.
Running? I hope by the end of the year (2020)


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## Foketry (Dec 1, 2020)

OllyM said:


> That is beautiful work, absolutely superb! I've been using a resin 3d printer for mechanical parts (gears, brackets, mounting frames etc). One thing to bear in mind is that most of the resins are very brittle, very much like acrylic. I've used purpose made engineering resins have much better mechanical properties, although they aren't cheap. Here's one supplier that I've used:
> Formfutura Engineering Resins
> 
> The clear type is less brittle, the grey type is very very strong, and heat resistant.
> ...


Thanks for your suggestion, I have read the mechanical characteristics, they are great, but what does it mean ? :
_Test method on post cured objects through 10 minutes high power *mercury curing *_
Is mercury curing the same as UV curing?
The manufacturer is Dutch, maybe I find this resin also in Italy, the price is at least 50% higher than the standard resin, but I want to try it.
Regards


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## cds4byu (Dec 1, 2020)

Mercury discharge lamps have spectral lines at 405 and 385 nm.  405 is a standard wavelength for photosensitive resins an home printers.  385 is a standard wavelength for laser-based sla printers.

Carl


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## OllyM (Dec 2, 2020)

Yes, they just mean UV curing after printing and clean up. All the resins need something like that, although I've yet to see any that have a datasheet specifying exactly how much UV they need (intensity / mm^2 or whatever). Also helps to warm the part up.

They are very expensive compared to regular resins. I usually use a cheap resin for proving the design before using the good stuff for the final part. The "heavy duty" is recommended for printing moulds for plastic injection moulding, to give an idea of it's strength. The print settings need expose quite a bit longer per layer as well.

Cheers,

Oliver


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## ALEX1952 (Dec 2, 2020)

Another method of engine turning which I have used to good effect on scale mode aircraft is a wood dowel of a size to suit scale and lapping paste, used at a modest rpm & pressure, speed and grit is varied to achieve desired appearance. Apologies if I'm teaching you to suck eggs


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## bruski (Dec 3, 2020)

Doesn't any body but my area have sunshine to cure the resin parts?

bruski


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## OllyM (Dec 3, 2020)

I'm in Scotland, so no sunlight here 

Cheers

Oliver


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## Jennifer Edwards (Dec 4, 2020)

Your post has reminded me of my youth when I helped my father build a Buick straight eight with eight little Webber carb. We mounted it in an old “rail” dragster frame he had and took it to the track. 
I remember well the roar it made as he drove it.

good luck with your model


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## Foketry (Dec 4, 2020)

Jennifer Edwards said:


> Your post has reminded me of my youth when I helped my father build a Buick straight eight with eight little Webber carb. We mounted it in an old “rail” dragster frame he had and took it to the track.
> I remember well the roar it made as he drove it.
> 
> good luck with your model



Very interesting, can you  share some photos of the Buick 8 ?

Jules


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## Jennifer Edwards (Dec 5, 2020)

Hi Jules,

at the time I was about 12 years old, I’m noW 64, and unfortunately if there are any surviving photographs they ar3 not in my possession.

to describe it a bit more:

 it was a flathead motor. I’m not sure what year the motor was, most likely early 50’s if I had to guess. I do know that a lot of Buick flathead seights were converted into marine engines. 

Dad fit eight little Webber carburettors to it. I can recall him constantly fiddling with them, watching the exhaust pipe for that cylinder as he did.

He had welded up eight separate exhaust pipes. Swept down and to the rear, perhaps 18” long.

it was hooked up to a three speed transmission and the shifter came right out the top of it.  In fact it is how he decided where to place the seat, roll cage, and other controls.

it was basically a 1960’s front engine dragster.

He ran it as a “Class ‘C’ Econo Rail”. The NHRA has since done away with the “Econo” class, which if I recall correctly was: home built, naturally aspirated, gasoline & carburettors for fuel class. The class was designed to allow the backyard mechanic with limited resources a way to compete.

it has since been replaced with the “Sportsman’s Class”. You would need a good $150,000 to compete in that class. When it superseded the “Econo” class, drag racing for

the car was not very competitive as small block V-8’s were also lumped into class “C”.

Dad had built other cars and did ok for a weekend warrior. That thing I think was just his way of trying to make a point. A point that I have no clue about

Being Daddy’s Girl, tinkering with my father in his shop, is how I learned to appreciate things mechanical.

Hope this helped you visualise it a bit more


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## ddmckee54 (Dec 7, 2020)

In the mid 70's my Auto Mechanics instructor was running a Javelin in the local stock car races..  What was special about this car was that he was using a Hudson straight 8 flathead engine, and winning.

My instructor, who flew B-24's in WW2, said that his father had been the local Nash/Hudson dealer and he would never forgive him if he ran any other engine.

Don


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## Foketry (Dec 15, 2020)

The original Bugatti radiator consisted of an outer frame and thousands of small tin-welded brass tubes, air passes inside the pipes and the water flows outside the pipes from top to bottom
Between one pipe and the other there is a small space where the water flows, the pipes are welded at the 2 ends and do not allow the water to escape


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## Foketry (Dec 15, 2020)

I studied how to reproduce it the same, by welding small 4 mm diameter pipes, but over 1000 pipes would have been needed, so I adopted another solution.


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## Foketry (Dec 15, 2020)

I printed an external plastic shape with a 3D printer and then cast it in aluminum
I wasn't sure I could bend a brass U-profile around the shape without heating it, so to avoid problems I made the external shape with aluminum casting


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## Foketry (Dec 15, 2020)

I wrapped the U profile around the shape, very slowly and without forcing, but it was not necessary to heat the brass and  inserted a PC  radiator  inside.


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## Foketry (Dec 15, 2020)

To simulate the grid of the front and rear tubes I used 2 commercial perforated aluminum sheet, enlarging the holes from 2mm to 3.7mm
This activity cost me hours and hours of drilling, and several recharges of batteries


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## michelko (Dec 15, 2020)

that looks phantastic!!!


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## Peter Twissell (Dec 15, 2020)

I would have thought the 'scale' brass tube structure could have been soldered using paste.
Your solution avoids potential issues in the future, using a commercial PC radiator.


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## Foketry (Dec 20, 2020)

Exhaust pipes, as shown in the photo of the original engine, the exhaust pipes are grouped 4 in 1, I tried to replicate them, designing the 4 in 1 manifold.






the manifold project , from this project I made a plastic mold and then a brass casting






the plastic mold, still attached to the 3D resin printer plate


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## Foketry (Dec 20, 2020)

The brass cast manifolds






manifolds in  drilling phase


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## Foketry (Dec 20, 2020)

exhaust pipes after brass welding and after painting with high temperature paint


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## Foketry (Dec 20, 2020)

assembled to the engine


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## delalio (Dec 21, 2020)

That is some awesome work. Great demonstration of several skills there. I tip my hat to you Sir!


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## Foketry (Jan 9, 2021)

The blower, I built and milled all the aluminum castings but for now I install it without the rotor bilobe , first I have to start the engine only with the carburetor, without unnecessary complications

The original blower








My drawings




Cover



2 Bi-lobe rotor



My aluminum casting obtained through the lost PLA / plaster method









After milling and sandblasting




partially assembled


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## Foketry (Jan 9, 2021)

The blower assembled to the engine


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## Peter Twissell (Jan 9, 2021)

Superchargers are pure engineering porn!
Wonderful.


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## gbritnell (Jan 9, 2021)

Fabulous work! The detail is first rate!


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## michelko (Jan 9, 2021)

Wow that blower came out reale nice


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## ajoeiam (Jan 10, 2021)

Foketry said:


> The blower, I built and milled all the aluminum castings but for now I install it without the rotor bilobe , first I have to start the engine only with the carburetor, without unnecessary complications
> 
> The original blower
> 
> ...



I'd be curious as to how you fabricated and machined the bi-lobe rotor - - - please? 

(That is if you are going to create it or have created it! Merci beaucoup!)


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## Foketry (Jan 10, 2021)

ajoeiam said:


> I'd be curious as to how you fabricated and machined the bi-lobe rotor - - - please?
> 
> (That is if you are going to create it or have created it! Merci beaucoup!)



Maybe in  future, if the engine works well, I will complete the blower with  2 rotors
The rotors will be printed with 3D printer, aluminum poured  and milled only on the small rectangular protrusions you see in the model photo. Of course I will also make the 2 central holes to lighten the rotors
Extreme precision is not necessary because it is only a fan, +/- 0.1 mm is enough, in my opinion , i hope


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## Peter Twissell (Jan 10, 2021)

Hi Foketry,
In my experience of this type of supercharger, i.e. positive displacement, as opposed to a turbine type, it is important that the rotors have very small clearances.
When the rotors become worn, the efficiency of the blower degrades quickly to the point where it takes more power to drive it than is gained from the boost.
If I were making a blower with long rotors like the Bugatti design, I would probably make them in short, manageable sections, keyed to a shaft.

Pete.


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## stevehuckss396 (Jan 10, 2021)

It doesn't take much to spin the blower unless it's making boost. If clearances are real loose it will not make boost and wont steal much power. Of course it would make more sense to leave the case empty if you don't plan to make it fully functional and at least make enough boost to replace the power lost to the blower load.


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## Foketry (Jan 11, 2021)

Peter Twissell said:


> Hi Foketry,
> In my experience of this type of supercharger, i.e. positive displacement, as opposed to a turbine type, it is important that the rotors have very small clearances.
> When the rotors become worn, the efficiency of the blower degrades quickly to the point where it takes more power to drive it than is gained from the boost.
> If I were making a blower with long rotors like the Bugatti design, I would probably make them in short, manageable sections, keyed to a shaft.
> ...


Hi Pete
I have no experience with blowers, I got information in a workshop near me that restores vintage Bugatti, he told me that there was clearence between rotor-rotor and rotor-casing, over 0,1-0.2mm (0,010 inch) 
I saw the disassembled rotors and the finish was not particularly sophisticated
You must consider that we were in 1923-1930 , at that time in the United States the Ford T was built
I found on  internet ,months ago, an analysis of clearance and leakage, about bi-lobe blower, analysis speaks of clearance 0.011-0.014 inch
In any case it would be my great happiness if my engine ran ,even without blower

The analysis , a page of 11


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## Foketry (Jan 11, 2021)

stevehuckss396 said:


> It doesn't take much to spin the blower unless it's making boost. If clearances are real loose it will not make boost and wont steal much power. Of course it would make more sense to leave the case empty if you don't plan to make it fully functional and at least make enough boost to replace the power lost to the blower load.


Hi Steve
Yes correct , at the moment I leave the case empty, I don't know if the engine will work well without blower, I'm not looking for complications.....


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## Foketry (Jan 11, 2021)

The head cover, underneath, flows the cooling water which, through 4 flanged pipes, collected in a conical tube, goes to the radiator

after chrome plating














after brazing


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## ajoeiam (Jan 12, 2021)

Foketry said:


> Hi Pete
> I have no experience with blowers, I got information in a workshop near me that restores vintage Bugatti, he told me that there was clearence between rotor-rotor and rotor-casing, over 0,1-0.2mm (0,010 inch)
> I saw the disassembled rotors and the finish was not particularly sophisticated
> You must consider that we were in 1923-1930 , at that time in the United States the Ford T was built
> ...



Please - - - would like the reference to the article (if possible)?


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## Peter Twissell (Jan 12, 2021)

Re. Supercharger clearances:
The clearance will need to be smaller in a small blower, both in proportion with the rotor diameter and because the smaller blower has a cube law capacity relationship to a larger one and a square law leakage relationship.
So if the blower is simply scaled down 1:2, it will have 1/8 capacity but 1/4 leakage.
A leaky blower will consume almost as much power as a good one. The rotors displace exactly the same volume, but much of the flow is wasted as it leaks back from the hp side to lp.


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## Foketry (Jan 12, 2021)

ajoeiam said:


> Please - - - would like the reference to the article (if possible)?



here is the link:


			https://downloads.hindawi.com/journals/ijrm/2006/079084.pdf


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## Foketry (Jan 12, 2021)

Peter Twissell said:


> Re. Supercharger clearances:
> The clearance will need to be smaller in a small blower, both in proportion with the rotor diameter and because the smaller blower has a cube law capacity relationship to a larger one and a square law leakage relationship.
> So if the blower is simply scaled down 1:2, it will have 1/8 capacity but 1/4 leakage.
> A leaky blower will consume almost as much power as a good one. The rotors displace exactly the same volume, but much of the flow is wasted as it leaks back from the hp side to lp.



yes i agree, i had not considered the size, my blower is 3.3 times smaller than the original, it means the max lobe / lobe clearance should be 0.03 mm (0.001 inch)  
I can not maintain these tolerances with my self built CNC milling machine, on such a complicated profile
I will leave the blower empty


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## ajoeiam (Jan 13, 2021)

Foketry said:


> here is the link:
> 
> 
> https://downloads.hindawi.com/journals/ijrm/2006/079084.pdf


Thank you. 
Now time for digestion and coming up with a plan for manufacturing - - - grin!


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## Peter Twissell (Jan 13, 2021)

Ajoeiam - I am going through the same exercise.
My first thought is to machine the rotors slightly oversize, then run them together with abrasive in a purpose built fixture with adjustable pitch centres.
I used a similar process to make cheap steel gears fit well enough to make oil pumps.


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## Foketry (Jan 24, 2021)

Bugatti engine is finished, ready to test if it works
Dimensions: length 60 cm (23,6 inch), width 30 cm (12.8), height 38 cm (15), weight 24 kg (52lb)


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## Brian Hutchings (Jan 25, 2021)

Can't wait to see and hear it running.
Brian


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## Chiptosser (Jan 25, 2021)

Another Beautiul piece of Art!


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## Mike Henry (Jan 25, 2021)

Congratulations!


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## petertha (Jan 25, 2021)

Very nice. Good luck on the start up!
Maybe I missed it, but what did you end up doing for oil lubrication pump(s).


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## Foketry (Jan 27, 2021)

petertha said:


> Very nice. Good luck on the start up!
> Maybe I missed it, but what did you end up doing for oil lubrication pump(s).



I initially thought of putting an oil pump to lubricate the cams then instead I filled the cavity of the camshaft with good grease for bearings , the camshaft cover closes and hides everything
To prevent the intake valves sucking the grease I put a seal on each valve stem.
The crankshaft turns on bearings and the oil sump is filled with oil.


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## Foketry (Jan 29, 2021)

Engine finished, here is the final video


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## Ghosty (Jan 29, 2021)

Congrats, it sounds like a very healthy engine.
Andrew


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## kuhncw (Jan 29, 2021)

Very well done and it sounds strong.

Chuck


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## petertha (Jan 29, 2021)

Its a runner! Very nice.


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## Jennifer Edwards (Jan 30, 2021)

Foketry said:


> Engine finished, here is the final video




lovely piece of work. Sounds wicked too. WELL DONE!


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## Hopsteiner (Jan 31, 2021)

That thing is purring like an angry kitten.


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## toadboy65 (Jan 31, 2021)

I have been following your progress with admiration. Wonderful work.
Now that the small-scale test version is complete, you can start on the 1:1 version. I will be happy to build the chassis, and we can be the envy of the country.

/s


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## Steamchick (Feb 1, 2021)

Foketry,
OOOHHH!!!! Wonderful! - I just love to see a "new runner".
CONGRATULATIONS on an excellent result for all the time and hard work that this obviously took.
Maybe we can fit in my Moto Guzzi chassis? - But maybe it is just too long...
K2


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## Foketry (Feb 1, 2021)

toadboy65 said:


> I have been following your progress with admiration. Wonderful work.
> Now that the small-scale test version is complete, you can start on the 1:1 version. I will be happy to build the chassis, and we can be the envy of the country.
> 
> /s


it would be a great idea, even a friend of mine proposed this to me, we could be 3 to collaborate on this project ....
A few months ago a replica of the Bugatti T 35, 8-cylinder straight engine, was sold at auction in California for $ 234,000 (manufacturer Pur Sang, Argentina)
I'm joking , if I had a car like that, I would never sell it


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