We have all been very conscious of wear additives in our engine oils. Now companies are adding zinc/phosphorus to everything and it turns out it isn’t a good idea in some applications. Engine assembly lube with extra wear additives should only be used on camshaft lobe and lifter faces, not on bearings surfaces.
If you coat plain bearings and leave them a long time, it will attack the bearing material. How long is a long time? Good question. I can say five years for sure. When the problems start is hard to say. My boss overhauled a Jag XK engine for a job but the owner changed his mind and wanted a larger, hotter engine. So the 3.4 sat for five years before it was sold. Fired up fine and good oil pressure for a week or so. Then the oil pressure started dropping. Pulled the pan and all the bearings were down to the copper. Thankfully, no damage to the crank. New bearings and it was happy again. We checked with a few other builders and this issue is known.
Use engine oil or Lubriplate 105 on all plain bearings when assembling an engine. If it ends up sitting for a while, make sure you pressurize the oil system externally before turning the engine over.
YMMV
