Single cylinder horizontal enigne as test bed for multi cilinder engine design

[xander janssen]

Now the engine is running reliably, time to replace the screws by studs and custom made high profile nuts.

 

[xander janssen]

 

[xander janssen]

Stable running with the new carburetor. Still there is a very low frequency oscillation in the rpm i.e. slowly increasing and decreasing about once a minute minute.

Now it is time to take it apart, degrease, prime and paint it red

 

[xander janssen]

Starting the paint job

 

[xander janssen]

Primer and paint were difficult to process.

Both are rather thick, cannot be diluted and are supposed to be used in a rather thick layer.

Given that I only wanted to apply a thin layer, not to obscure detail, the paint dried rather quickly into a paste leaving a lot of brush strokes visible.

Ended up to stipple the paint onto the parts, which gives them a sand-cast appearance and all the brush strokes disappeared.

The end result is rather impressive.

 

[Steamchick]

Clever idea to stipple the paint. Must try that one...
K2

 

[xander janssen]

Lets see if it also runs on a proper carburetor. Chuck Fellows design with a tapered air inlet

 

[xander janssen]

Building the gas tank from some parts in yhe scrap bin: square tube and 2 discs (scrap from a stamping press) that fortunately have a diameter that fits the diagonal of the tube.

Soft soldered together and quite pleased to see that the seam becomes nearly invisible after cutting off the excess material and some filing.

Finally the tank will be sanded and polished to remove (nearly) all dents and scratches and then giving a matt appearance with some scotchbite.

 

[Steamchick]

Hi Xander, personally, I should have fed more solder and flux to the inside of the tube to form a fillet there, as you are deliberately removing the external fillet of solder with the external material, and if you radius or chamfer the corners will have very little of the square tube metal for the solder to have any strength. Pre-formed shapes of flux-cored solder fitted inside the tube when assembling the final end can achieve a fillet, but capillary action through from the outside won't do that. IMHO?
I should have silver-soldered the assembly simply because I can, and it is a stronger joint material.
K2

 

[xander janssen]

Hi Xander, personally, I should have fed more solder and flux to the inside of the tube to form a fillet there, as you are deliberately removing the external fillet of solder with the external material, and if you radius or chamfer the corners will have very little of the square tube metal for the solder to have any strength. Pre-formed shapes of flux-cored solder fitted inside the tube when assembling the final end can achieve a fillet, but capillary action through from the outside won't do that. IMHO?
I should have silver-soldered the assembly simply because I can, and it is a stronger joint material.
K2

Indeed, room for improvement. Given that the tank will not take any mechanical load, I deemed this to be sufficient. Next time I will indeed also add preformed solder from the inside. However, it is difficult to tell if that has completely melted as you cannot look into the tank anymore. Hence my decision to add from the outside. The tube has a wall thickness of 2.5 mm (0.1 inch) and a test piece shows that a proper soldered joint with that thickness can take quite some load.

Anyway, I will pressure-proof test the tank to 2 bar (30 PSI) before use. If it fails, I have to repair. If it passes, I doubt that the tank will break down in future. Especially since the engine will hardly ever run and spent most of the time in the glass cabinet.

Next on my "competence to learn" list is brazing/silver-soldering as that is indeed a much stronger way of joining parts together.

Regards

Xander

 

[xander janssen]

Running on a true needle carburetor by Chuck Fellows design.

 

[xander janssen]

Routing the wires in a neat way on the new/final base.

 

[xander janssen]

Done

 

[xander janssen]

I wrote a building report that got published in the German magazine " Maschinen im Modellbau"