By Jupiter

[crueby]

Wow. Was looking at the casting, thinking it looked great, then spotted the coffee cup and realized how small it is. Very nice! Great job on the molds, was well worth the extra tries.


 

[Vixen]

Thanks everybody for calling by and saying hello 

I made some measurements to determine the actual shrinkage rates at the various stages. The master patterns were made 3% oversize. Silicone rubber was cast over the master patterns and the wax model was cast (injected) into the silicone mould. The wax model had shrunk slightly and was now a little over 2% oversize. At the foundry, they cast the investment slurry (looks like Plaster of Paris) over the wax model together with the wax runners and risers. The wax was burned out over a 12 hour period raising the investment flask to red heat. The molten aluminium was drawn into the heated investment mould cavity using a special vacuum caster. The finished aluminium casting was measured to be between 0.5% and 1% oversize. I am happy with this, a slightly oversize casting is always preferable to undersize. If I go down this route again, I will start by making the master patten 2.5 % oversize instead of 3%.

Craig, model engine parts were something new to my jeweler, the were very enthusiastic and helpful and keen to add model engine parts as a new business opportunity.

Zee, with lots of practice you will learn and gain experience. You can then use your experience to make the same old mistakes as last time, but with greater confidence than before.

Mike

[Admiral_dk]

You can then use your experience to make the same old mistakes as last time, but with greater confidence than before.

    Thank you for that one Mike - I needed a good laugh. + I'm sure it WILL happen to me again sometime 

Oh, and I do still enjoy your fantastic journey with this jewel 

Per

[Art K]

Mike,
I also noticed the coffee cup, great for scale.

with lots of practice you will learn and gain experience. You can then use your experience to make the same old mistakes as last time, but with greater confidence than before.

Remove Zee insert own name.
Looks great.
Art

[zeeprogrammer]

with lots of practice you will learn and gain experience. You can then use your experience to make the same old mistakes as last time, but with greater confidence than before.

Remove Zee insert own name.

Might work for you all...but not for me. Zee = Zee.

Wonderful quote. 

[Art K]

OK be that way, but I still like the quote.
Art

[Vixen]

I have completed some initial cleaning up of the Induction Manifold using a sharp file and the Dremmel. I will complete the final surface finishing when all the other work is completed on the manifold.

The first thing I wished to accomplish was to attach the Induction Manifold to the rear of the engine. This required some more fabrication work on the Rear Cover to add three inlet stubs. The Rear Cover had previously been manufactured some time ago. It was straight forward turning work for a large lathe, in this case it was turned on a rotary table using a ball mill to contour the outside and inside curved surfaces.

Here is an image, from my works handbook, showing, left to right, the rear of the Crankcase, the Induction Spirol and the Rear Cover. I will discuss the Induction Spirol later.

 




I machined up the three inlet stubs, complete with the mounting holes and super-glued the stubs to the Induction Manifold. This allowed me to accurately transfer drill the 12 mounting holes into the flanges. Then I co-ordinate drilled a simple fixture plate to hold the three inlet stubs in the correct orientation. Using this fixture, I was then able to profile the curved surface with numerous passes with a 8mm ball cutter. The super glue joint holding the stubs to the manifold was easily undone with a sharp tap with a small hammer.





After profiling the mating face, the three inlet stubs were permanently bonded to the Rear Cover using JB Weld epoxy. The 12 mounting studs and six more additional countersink screws were drilled and tapped through both the inlet stubs and Rear Cover to make a very strong and permanent assembly





A full set of 12 8BA studs were made and secured in place. Miraculously all 12 studs lined up with the holes previously drilled in the Induction Manifold flange.






Here we can see the Rear Cover and Induction Manifold nestling neatly at the rear of the engine, with the 'accessories' gearbox in the center of the Spirol. That big Induction Manifold casting is beginning to look quite small on the back of the mighty Jupiter engine





The Bristol Jupiter MK VIII was un-supercharged, instead, it had a unique (patented) Induction Spirol buried in the rear of the crankcase. It's purpose was to distribute the fuel mixture from one of the three carburetter barrels to three cylinders. The spiraling airflow was designed to keep the fuel/ air mixture in constant motion and so prevent it separating into droplets. The numbers cast on the back of the Induction Manifold are there to tell the maintenance engineer which cylinders relate to which carburetter barrel.

More on the Induction Spirol later.





Stay tuned

Mike

[crueby]

Thats quite a sophisticated bit of engineering, learning a lot!


 

[zeeprogrammer]

I cannot express enough my 

Wow. What engineering and modelling.

[Admiral_dk]

Miraculously all 12 studs lined up with the holes previously drilled in the Induction Manifold flange.

Oh that is so great when you discover that one of the possible          did not happen, but all is good phew  - great work Mike 

[steamer]

Beautiful work Mike!    Nice bit with the manifold flanges!


Dave

[Ye-Ole Steam Dude]

Sure am enjoying and being amazed by your work, thanks for sharing.

Have a great day,
Thomas

[Vixen]

Thanks Guys,

Not much progress to report other than making and fitting the exhaust heater pipe and flanges, which runs from side to side in the Induction Manifold. It's purpose was to heat up the fuel/ air mixture by ducting some of the exhaust gasses through the pipe. This was done to prevent icing at high altitudes.



I have been distracted by an extensive modification program on my Emco VMC100 mill. I have been fitting new motors and controllers and new spindle bearings.

Mike

[steamer]

Do keep me informed with the machine upgrade!

[Tennessee Whiskey]

Amazing build Mike  . When I learned to fly in a Cessna 150, there were two controls for cabin heat and carb heat, one sent the heat to the cabin and one sent the heat to the carb for deicing, and they both came from the same source, the exhaust manifold.

Cletus