The bigger the engine the more powerful the surge and flame flash. Scary as hell to the passengers but not a big deal if dealt with by the pilot (retard to clear multiple surges). However if left in a surge condition for 10 or so surges then you may end up permently breaking the engine (varies by engine model).
Many many years ago there were some engines that broke after only a single surge, but almost all engines today are designed to last out at least 10 high power surges before cashing in. That of course assumes that the engine hasn't already broke and the surge was secondary