Aluminum Oxide / Paint motor in frame?

Hey KZ World.

As you see my photo, i've cleaned my motor with aluminum wheel cleaner. did a great job of breaking off the oil and grime that is 30 years old... but it has apparently stripped any kind of clear coat. Now... it is frostier than santa's beard.

I need suggestions of what cleaners / sealers to use. My dad - a chemical engineer said to just paint it, cuz there isn't a way to prevent aluminum oxide.

Anyone ever painted a motor while in the frame?

Motor looks good by the pics. IMO. I just did mine and pulled the motor to do it. Its much easier to get to the hard spots.
Here's a pic of mine so far.

IMO it was easier. All depends on what you want.

2 hours i stripped the parts, prepped and painted... VHT Cast Aluminum Engine Paint. Decided not to paint the carbs. I cleaned them and used a clear coat for aluminum.

Looks Great! Hope mine will turn out as well as yours.

Steve