I am rebuilding an engine and i want it to look great. all the aluminum has oxidization on it how do i get rid of it and what is a good product to use to polish it too.

This says wheels but applys to your job ahead
For polishing or cleaning an aluminum wheel or wheels first check for clear coat (this has to be removed to polish ex: Sanded off). The Polishing is usually a two step process. First using P-327 Tripoli and a buffing wheel remove scratches and blend out for the first step. Second using P-130 Jewelers rouge and a new buff, finish out the fine lines and blend. The last product we recommend is our new liquid L-1000 hand polish for basic cleaning, polishing, and protection.

When polishing aluminum, brass copper, pot metal, and soft non-ferrous metals, use tripoli or gray compounds by holding the bar up to the wheel while it is spinning. Let the buff spin about three or four turns on the compound, while moving the compound in a clockwise motion. (NOTE: Do not use water with compounds). If you can hold the part under the wheel after loading, you'll notice the compound spitting on the part when there is enough on the wheel. At this point your wheel is loaded and your ready to begin the polishing process. It is very important to load your wheel every 20 to 30 seconds and keep the heat up on your part. Keep the part moving under the wheel, this will keep you from burning the metal. Never touch the edge of the part to the wheel, this will keep the part from being pulled from your hands.