Close-up of bare cast-iron engine block deck with head bolt hole…

Tight close-up of a bare cast-iron engine block's machined deck and lifter valley, showing head bolt holes, a coolant passage, machined lifter bores and a square-drive threaded plug installed in an oil gallery. The casting is clean and dry with a light gray machined surface against the rough dark iron.

AI caption February 2008 · Photo 35 of 102