these SAE class motor oils are definitely not the right choice for this application! They usually contain cleaning additives and stabilizers which are counterproductive for the function of sintered bearings.
Sintered bearings need an oil that is able to immerse into the pores of the bearing sleeve and, once applied, provides a continuous 'micro-flow' of lubricant as needed to bridge the bearing play/gap. You should look for a synthetic oil since mineral oils deteriorate over the time, get sticky and cloak up the pores in the bearing.
Here in Europe, definitely the best product for sintered bearings is Kluber IsoFlex PDP65. In the US, Athan Corp for example carries a similar oil, look for ATH-LUB-1. Not sure which brand they re-badge. These oils are relatively expensive in general, but the products-to-go. There are certainly other products available in the US which do the job, the difficulty is rather to get them in small volumes. You won't need a gallon of it in life time, except you want to throw a sinter lube party...