Powerful engine muddled black sheep (6)
I believe the answer is:
ramjet
'powerful engine' is the definition.
'ramjet' can be an answer for 'engine' (ramjet engine is a kind of engine). I'm not sure about the 'powerful' bit.
'muddled black sheep' is the wordplay.
I cannot really see how this works, but
'black' could be 'jet' (similar in meaning) and 'jet' is present in the answer.
'sheep' could be 'ram' (male sheep) and 'ram' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ramjet that I've seen before include "Type of aircraft engine" , "Type of air engine" , "starter engine" , "Type of aero-engine" .)