Demoiselle boxer twin

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I made parts for the intake manifold.


Finish machined and polished.
Hi Andy,
The parts were made from solid, milled, drilled, turned, filed, sanded, polished.... with the occasional amount of elbow steam.
The milling operation is shown above. You cannot solder aluminium with silver, there are methods of soldering aluminium but the melting point of some of this soldering metals is only 10-20 degrees lower than the melting point of the alu itself so this operations are always a bit tricky.
I did, however ,do some silver soldering on the exhaust tubes. I used copper tubing with some flanges that were left over from the Edwards project. Flanges were soldered before the tubes were bent. The soldered flanges were bolted to a piece of aluminium that I used for machining the center holes of the flanges.. Prior to bending I filled the tubes with lead by putting small pieces of lead in the tubes and heating them up with a torch till the lead was molten.
meltdown 3.jpg

After that, bending was easy with an old bending jig that I had lying aound for many years.


After bending, the lead was removed by heating again.

Finally, a bit of polishing...

Hmm, thought I had replied to this, but my reply isn't showing up. Maybe I just thought my reply and hoped everyone would read me mind ... :)

I hadn't realized the part was aluminum - certainly understand that solder was not an option in that case. Again, great work!
Once the pipe was filled, did you just bend the tube over by hand? (most I've seen have some kind of lever arm & sliding shoe).
Is that material like what used in automotive brake line (easier to bend) or if its plain copper pipe, did you have to anneal beforehand?

Hi Peter,
I bent the pipe by hand because I did anneal it . The pipe came out of my "stock" , it is just ordinary plumbing quality copper.
The only special thing about this is that the original dimensions were 8 x 6 mm which I found a bit heavy. So I turned the OD down to
7 mm which, apart from weight reduction, made is easier to bend.

Last week I made the cam gear cover. A bit fiddly, fitted to the rear cover with 8 M2 Allen bolts. But in the end it looks rather nice .

Progress! Can you tell me more about the rocker arm assembly.
Is the valve contact pad hardened tool steel & then pressed in with Loctite or something? Hard to tell from picture but maybe you profiled the curve shaped the end? Looks like your adjuster is maybe an ordinary set screw? Did you ball end mill the pushrod end?

Yes the contact pad is silver steel ( a.k..a. drill rod) circular shaped at the contact end, hardened and fitted with a light press fit and epoxy.
The set scew is ball shaped, the push rod ends will have ball shaped hollow ends ( yet to be made).

I made a start with the camshaft.First I made a dummy shaft from aluminium for test fitting in the crankcase in order to verify dimensions and to practise machining of the cam lobes.
Being inspired by Brian Rupnow's radiused cam design I made a jig to machine the cam lobes of my camshaft. Now this is a rather tiny part so I made a tool from a piece of tube with a cutaway section. End pieces in the jig are used to fit the shaft which is held in place by Allen bolts acting as setscrews. The pictures tell the rest of the story ( so I hope)

cam 3.jpg
I made the rockers but I was not satisfied with them. The pushrods were not perpendicular to the crankcase which meant that there were transversal loads on both rockers and cam followers. This problem was solved by new rockers with offset tappets.

The pictures below show the difference between the original ( not good) and the new rockers with offset tappets (good)

Next job: cylinder liners and pistons.


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