J,
not such a stupid question. However, I think most of the (sensible) answers have already been given.
The type of alloys used in engine construction are not typically malleable (bendable), especially under the kinds of stress imposed during a crash. As such engine block components would more likely fracture than crush during impact. in addition, as Manchild has said, damage to the engine is only one part of the equation - damage to any of the life support systems for the engine will kill it just as surely as physical damage to the engine structure