Not an engine, but...

[dgjessing]

I finally got into the bag of gears that came with my HF 7 x 12 lathe, and with the help of tubalcain's YouTube videos have begun to learn how to cut threads on the lathe. Lots of possibilities here ;D

 

[rake60]

Nice start!

You'll soon find yourself single point threading parts that could be much more easily threaded with a die,
just because you can.

It's an addiction within an addiction.

Rick