Remember, A clean engine is a happy engine

Whenever you rebuild an engine, be very careful to clean out all of the sludge from the sump. This has microscopic metal filings, than when you start your engine up for the first time, can cycle through the oil system. Now, more than likely the filter should filter it out. But sometimes those particles can get slung from the sump up to the connecting rod and crankpin area, and act like sandpaper in bearings.
And change your oil often, once a year is a good idea once your engine is broken in.

Very good information. I had friend who rebuilt his 2 cylinder Chery engine, he just left all of the old oil residue in it, he started it up and after about 2 weeks of driving he noticed it was running rough, he did a compression test and compression was low, and he got a bore scope and looked at the cylinder, it was all scratched up with vertical gouges. had to rebuild it again, but the 2nd time he took care CLEAN everything real good. Brake cleaner and WD40 are your friends.

Ouch! Yep, cleanliness is next to Engine running good-ness. lol