I’ve started polishing a spare intake manifold I have from another 4AGE I purchased. The intake is aluminum, and when it was cast originally it is covered in small pit marks and casting lines.

My goal is to polish the plenum and clean the underside well. So far I’ve managed to remove about 95% of the pits and casting marks from the plenum area. This was easily accomplished by an 80 grit sand paper wheel (drill attachment). I’ve been able to sand certain areas in different directions and seen a much more reflective result.

Along with the sand paper wheel purchase, I obtained 320 and 400 grit wet/dry sandpaper. The next step is going to be sanding out the marks from the 80 grit wheel. Supposedly at this point I will see the results starting to surface, so to speak