Cleaning / Refreshing Engine Appearance


I'm currently rebuilding several older GX270 engines and I wanted some advice on making them appear clean & shiny, like our newer engines. Is there a particular cleaner or process that you recommend, beyond brake cleaner? I've also included pictures below.

IMG_4446 - Older GX270 that is dark and dirty
IMG_4364 - Newer GX270 that is newer and shiny

Thanks again!