The Cylinder liners are quite simple. The main thing that I did wrong was make them out of steel water pipe. The pipe is not hard enough to endure the wear of a piston and rings. After running the engine for maybe an half an hour, the liner and rings were worn out. The liner and the rings should be made from cast iron.
After boring the cylinder liner, it should be finished with a lap. This will give it a fine close tolerance finish. The piston and rings can then be fitted to it.
Sorry, I dont have a picture of the cylinder liner.