A mod I did to my Milodon camshaft geardrive unit. I don't have much documentation on the modification (pics), but here's the one picture I do have.
The objective of this mod was to supply a pressurized oil supply to the idler gear bearing of the geardrive unit. A small hole was drilled into the face of the engine block in a position where it would break into the main oil galley that feeds the front main bearing. The passage that is shown in the picture was milled into the back side of the geardrive mounting plate. One end of the groove sits over the hole drilled into the block. The other end of the groove has a small hole drilled through the plate that breaks out the front of the plate in a position that will spray oil right at the idler gear bearing. The size of the hole is very small. The orifice is recessed on the back side of the plate and a tiny thimble type filter is fitted into the recess over the orifice to prevent it from becoming plugged. The filter is not in place in the picture. Also not in the picture is an o-ring groove that I machined around the oil feed groove. A rubber o-ring seals the groove when the plate is bolted to the front of the block.
The objective of this mod was to supply a pressurized oil supply to the idler gear bearing of the geardrive unit. A small hole was drilled into the face of the engine block in a position where it would break into the main oil galley that feeds the front main bearing. The passage that is shown in the picture was milled into the back side of the geardrive mounting plate. One end of the groove sits over the hole drilled into the block. The other end of the groove has a small hole drilled through the plate that breaks out the front of the plate in a position that will spray oil right at the idler gear bearing. The size of the hole is very small. The orifice is recessed on the back side of the plate and a tiny thimble type filter is fitted into the recess over the orifice to prevent it from becoming plugged. The filter is not in place in the picture. Also not in the picture is an o-ring groove that I machined around the oil feed groove. A rubber o-ring seals the groove when the plate is bolted to the front of the block.