Sort of engine not popular with directors (8)
I believe the answer is:
outboard
'sort of engine' is the definition.
(outboard engine is a type of engine)
'not popular with directors' is the wordplay.
'not popular' becomes 'out' (as opposed to in, fashionable).
'with' means one lot of letters go next to another.
'directors' becomes 'board' (board of directors).
'out'+'board'='OUTBOARD'
(Other definitions for outboard that I've seen before include "Type of boat engine" , "Detachable small boat motor" , "Engine external to the boat" , "Small boat's motor" , "Engine mounted at the stern of a small boat" .)