Ive just done all the alloy cast parts off my engine including head and sump and engine mounts....I used a wire wool scouring pad from tesco's along with washing up liquid then gave the parts a dry down and a wipe over with a rag lightly sprayed with wd40...gave a really nice clean look with a satin shine to it...ie not over the top/tarty. Missus wasnt too chuffed at the state of her kitchen sink tho lol

Stu.