Bruce Macbeth Engine, European Version

[Roger B]

Coming along nicely   

That long hole must have been tricky 

[crueby]

Watching along, great work!

[fumopuc]

Roger, Chris thanks.


Next part of the intake manifold, soft soldering of the carb adapter.
The adapter coated with some soldering paste and heated.
Some sanding for a better fit of the final soldering with paste in the discounter oven.
Making also some plugs to close the not needed sections of the bore.
And the intake manifold finally bolted to the cylinder heads.

[fumopuc]

Hi everybody, next part, the exhaust manifold.
This is a combination of water and exhaust collector.
Made from 2 parts hard-soldered.
A lot of holes inside.
Two 2 mm extra holes for pins to keep it in place during the soldering.
The exhaust tube is a bit oversize for later machining of the end cover surfaces after soldering.

[Craig DeShong]

This model is a real masterpiece Achem.  The work you’re putting In is marvelous.  Lots of little details that make it a very interesting model.

    I’ve been watching your progress; too nice to miss an installment.

[Don1966]

Awwww marvelous work Achim ........ 



 
Don

[gbritnell]

Still following and still enjoying the build. Outstanding work but I had no
 doubts!
gbritnell

[fumopuc]

Hi Craig, Don and George, thank you so much for following along and the friendly comments.


Next to do with the exhaust manifold, the recess for the nuts/studs to fixture it to the cylinder heads.
A quick test with a socket wrench immediately has given an idea about a later coming problem.
Some rework were done and socket modified.


Last picture my theoretical attempt how to start the hard soldering of the two parts. 
Its was a good idea to do it like shown in the CAD model, but as sometimes, physics has taught me something different.

[Roger B]

That looks quite a complicated soldering job 

I do like your powder coating finish     

[Admiral_dk]

Just thinking out loud - how about soldering a thin flat piece of brass between the underside of the rectangular (square) and round bit ? - so you offset the round piece just enough to clear the socket wrench ....

I can only concur that this model is getting better and better 

[fumopuc]

Just thinking out loud - how about soldering a thin flat piece of brass between the underside of the rectangular (square) and round bit ? - so you offset the round piece just enough to clear the socket wrench ....

I can only concur that this model is getting better and better 

Hi Per,
thanks.
It was more easy to modify a cheap Chinese socket wrench in this case.
And in the meantime, I have purchased also a better designed wrench for this application.

[fumopuc]

That looks quite a complicated soldering job 

I do like your powder coating finish 

Thanks Roger.


Soldering was a kind of new learning curve for me.


Set was done as in the CAD View. Both parts fixed by the two 2 mm pins and some wire wrapped around.
Some white out around the fixation holes to avoid any solder at this specific area.
Inside a lot of flux and the two 1 mm bars of silver solder inside.
Than a lot of heat.
First examination at the right side after cooling down looks fine.
Left hand side, the upper one O.K., the lower one no solder visible.
The flux is coming nicely through the gap but no solder ?
So I have repeated the process for the lower gap again.
Result again, no solder ?
So the questions was where is all my silver solder gone.
After cleaning it again with citrus acid, I could see all the solder inside the tube climbing up the radius.
So my assumption is that the flux in the V starts cooking.
The bubbles are pushing the silver solder bar inside up the wall of the radius and due to the heat  coming from outside specially at this area, the melted solder climbs up the wall.
Due to the moved position of the bar, we do have not enough solder (1 mm bar)  to go also down into the gap between the two parts.
So the result was, that may be I am the only one model engine maker who has an inside silver coated exhaust manifold.
Unfortunately it was my last available stick of this kind of silver solder.
I didn´t want to make any further experiments with different types of solder at this manifold so some Epoxy glue was prepared and the gap closed with it.
There is no special sealing necessary, it is only where the exhaust fumes are going through.
The both parts are safely connected by the upper soldering, so it should work this way.
Next job was to plug the water channel an to make the end cover and flange for the pipe.

[Admiral_dk]

Nice that you could solve the problem with a smaller socket 

I'm a lot more of a soft solder expert and just about nothing with regards to hard solder - so caution needed here - but solder tends to flow towards the hottest part ....

So I wonder if the part where you can't get it to flow, is slightly cooler than the other side where you got plenty ...?

Careful - you do NOT want to keep the flame fixed at the same spot - but keep it moving all the time. Done correctly, you can move the solder with the tip of the flame.
Not having the area that needs to be soldered clean enough can prevent the solder from flowing there ....

Now one last question - do you have water or exhaust gas where you do not have a perfect flow ?
In case of gas - you probably do not have a problem here .... water might result in a slow seepage ....

[fumopuc]

Nice that you could solve the problem with a smaller socket 

I'm a lot more of a soft solder expert and just about nothing with regards to hard solder - so caution needed here - but solder tends to flow towards the hottest part ....

So I wonder if the part where you can't get it to flow, is slightly cooler than the other side where you got plenty ...?

Careful - you do NOT want to keep the flame fixed at the same spot - but keep it moving all the time. Done correctly, you can move the solder with the tip of the flame.
Not having the area that needs to be soldered clean enough can prevent the solder from flowing there ....

Now one last question - do you have water or exhaust gas where you do not have a perfect flow ?
In case of gas - you probably do not have a problem here .... water might result in a slow seepage ....

Hi Per,
It took me some head scratching too and time to understand was was going on there.
It is not a heat problem, as shown in picture "BME AGA 17", two different heat sources were used.
The outdoor cooker gives a basic heat overall nearly 400° C, measured by an IR thermometer.
The torch, left hand in the picture is the second source for the "movable heat" to get it partly heated to 650°-700°C to let the solder flow exactly to the heat, as mentioned in your post.


But what has happen already during the early phase of the heating, is the cooking of the flux in the V.
This cooking fluid with bubbles are pushing the solder stick out of the ground of the V and up the radius inside the tube.
When it is getting hotter, the flux is getting constant again and keeps the solder stick in the below shown position.
All this is not direct visible, because that happens inside the tube.
I have watched this effect from time to time at other soldering operations.
The cooking flux pushes a bit solder away, you see it and it can be pushed back to the gap.
What happens next is the melting of the solder, due to the small volume, 1 mm bar, there is not enough volume to flow down, mostly to the heat and fill the gap at the ground of the vee-notch.


The water channels are not affected by this, it is exhaust fume, gas only.
 


 

[fumopuc]

Hi Everybody.
Next to do, final machining of the manifold. There was still some overstock.
Hole pattern for cover and exhaust pipe flange also made quickly by the computer.
The engine prepared and waiting now for the completed manifold first time.
Finally the exhaust pipe itself. A 12 mm tube has to be bent.
After thinking a while about to make a fixture by myself, I have seen a Chinese 12 mm tube bender at ebay for EUR 13,00, stock in Germany and no extra freight cost.
That was an easy decision.