Close-up of engine cylinder head with valve ports and '3-2', '3-…

Close-up of a metal engine cylinder head surface showing valve seats, spring seats, and bolt holes, with hand-written markings '3-2' and '3-1' stamped near two circular ports. The aluminum casting shows oil residue, discoloration, and metal debris across the machined surface.

AI caption October 2004 · Photo 567 of 2216