The most common and most likely answer to this crossword clue is the 8 letter word MOTORISE
I've seen this crossword clue in The Daily Telegraph
M
O
T
O
R
I
S
E
More clues leading to the result MOTORISE
Buddy explains!

The straight part
We know that "Provide with engine" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case provide with engine = motorise.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MOTORISE mean?
MOTORISE verb- To fit something with a motor.
- To supply something or someone with motor vehicles.
- To supply armoured vehicles; to mechanize.