Cleaning and Polishing Your Aluminum Valve Cover to Look Factory Fresh - On-demand Video | Product | MercedesSource.com
I spent 2 weeks polishing a valve cover to #200,000 grit and coated it with wax to keep it from oxidizing/squeeze out that last bit of shine. : r/Miata
Polishing My Valve Cover... - S2KI Honda S2000 Forums