After figuring out which side to mill first, I created custom T-slot hold down brackets designed to fit in the “valleys” of the engine block when turned upside down on the milling table.

1-2-3 blocks and shims were utilized to level the engine block as best as possible.

Using a facemill, I then milled the minimum amount off the bottom of the block and drilled/tapped holes for the bearing caps. The bearing journals were milled in one operation, oil galley holes drilled, and then the mounting pads on the side were milled square in order to later indicate the block after flipping it over. The engine block ends were also milled square at this point.

Using the same hole spacing for the bearing caps, I drilled and countersunk holes in a 3/4″ thick aluminum fixture plate to flip the block 180 degrees in order to mill the top.

I inserted two parallel bars in the bearing channel and held them apart with a spring to indicate and transfer the centerline to the top.

Next, clearance holes were milled for the connecting rods.

Then holes were drilled and tapped for the crosshead guides.

The block was then mounted at an angle in order to drill oil holes from the front down to the oil holes drilled in the bearing journals. An endmill was used to countersink the holes for the oil cups to be fitted later.

Main bearing caps were also fabricated and installed.