Do you have a prop on the engine? Many good ABC/N engines will lock at TDC when cold due to the tight piston-liner fit. This is a good thing. You don't notice it much on the plane, because you usually turn the engine over with the prop. With the prop off, you have no leverage. Bolt on a prop, shoot in some oil, and turn by hand. I'm not familar with Varsol, is that a cleaner that will remove oil? That's not what you want, you want a good coating of oil in the engine. Airtool oil is some of the best for this, Automatic Transmission fluid works, Maryvel Mystrey oil (as mentioned above) is very good too. I wouldn't use WD-40 because Wd-40 will gum up over time. I have used WD-40 in engines to help blow out dirt and get something unstuck though, it won't hurt anything in the short run.