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Questions on the oil holes in rod bearings. First time doing this.

I am using bronze (not oilite) sleeve bearings in the rods for a one inch scale L.E. Pacific. The cranks are 0.625 inch unhardened drill rod and the bearings are 0.75 OD. The side rods are 0.375 wide. The plan is to drill six staggered oil holes equally spaced around the bearings, and stagger alternate holes by about 0.2 to 0.25 inch. The holes will be connected by shallow (about 0.015 or so) grooves on the outside of the bearing as in Nelson's book to distribute the oil. The main rod is 7/16 wide so the stagger will be a little larger. There will be a hole in the top of the rod end to put in the oil. The bushing is sized to float (rotate) in the rod. Now for the questions.

1. How big should the holes for the rods and the bearings be to get enough oil without leaking all over?
2. Where do I make the "cross groove" to get oil from the hole in the rod to the grooves in the bearing? Is this in the rod or the bearing? I assume that this is to be an axial groove that is long enough to cover the stagger in the holes for the bearing, but does not reach the full width of the rod so the oil does not leak out.
3. Instead of an axial cross groove, can I turn a shallow groove around the circumference of the sleeve bearing, or in the inside of the rod, that is located at the location of the oil hole to distribute the oil?
4. Do I need to also groove the inside of the sleeve bearing to connect the holes, or will the oil spread around the crank pin adequately with the bearing clearance alone?

Thanks for any advice.

Lefty (George)

A topic with more opinions than facts!

From Handbook for Machine Designers...

"Regarding oil grooves, there is great diversity of opinion and practice. With film lubrication their presence on the pressure side of a bearing would likely do more harm than good, while with ordinary lubrication, the reverse is true. Some advocate blind ended grooves to avoid escape of oil, while others object to blind grooves because of their liability to become clogged and useless. With film lubrication, open ended grooves are obviously inadmissible. One point is settled - the edges should be well rounded to facilitate the entrance ofoil tothe bearings and the same is true of the meeting edges of split boxes. Sharp edges of grooves act as oil scrapers, not oil distributors."

Leakage is a given.

Personally, I prefer few holes and fewer grooves to encourage film lubrication.