The BEST of the BEST for your RE Engine shine is a product called
"SimiChrome". Your engine (aluminium or alloy or any metal) your Forks, and your Chrome will Shine and you will very impressed with the results. I have been using the same for about the time i got my bake, which is since June 30 2012.
Its takes just a little bit of elbow grease (use gloves) and you will be able to see your face in the shiny engine (in case you are camping and need to shave or use it as a mirror
or ... you know what i mean. Google it ( its made in Germany ) but its available from Ebay/Amazon for about $30.00 a can. I use it about every 2 weeks and it maintains a great shine, while at the same time covers the metal with a light protective covering
Cheers.