The Little Angel

24-Dec-06
What Have I been doing lately? Well, while I think and ponder about what to do with the BECO 2.0 engine, I ease my mind by building a proven design. When I get frustrated with the BECO, I take a break and work on the Little Angel.
This Engine was designed by the late Bob Shores. It has been built many times by other modelers and I am hoping that I will not have problems making it run properly.
I started work on this engine 4 or 5 years ago. I made the crankshaft and several cylinder heads. I could not get the cooling fins spaced properly on the cylinder head, and kept making more until I was able to make one that was acceptable to me. Then I needed a large piece of aluminum for the frame, which I didn't have. So, while I looked for a piece to make the frame from, I stopped work. Finally about 2 years ago I got a piece of aluminum big enought to make the frame. Then about 2 months ago (Oct 2006) I began working on this engine again.
Now It is starting to take shape. I increased the bore of this engine from what the plans call for, the plans say .500 dia. bore. I increased it to .610, now my cylinder heads don't fit!
So I made another... and another... Then I decided to put my own style of fins on the head using the rotary table. I made two of these. The first one I tried drilling the head bolts after the fins were cut. That doesn't work on these small fins. I had to make another one and drilled the head bolts before cutting the fins.

When I fitted the cylinder to the frame, I set the piston to the center of the port, as instructed, and drilled the holes. Then I checked the piston again, it had slipped while drilling the holes. Now the piston covers about 2/3 to 3/4 of the port. This will make the compression ratio higher. So to compensate for this, I cut the head a little smaller so that it doesn't go so far into the cylinder.