Fairly simple answer, not much.
The same engine in other F/W installs runs continuously at around 275 hp.
Your MP limitation applies to the max continuous power ( from memory 220 hp???) that you are allowed to put through the xmon. Therefore the engine cooling system is designed to keep the engine cool at that power rating. - continuously-
Make sure that someone hasn't put a bigger engine cooling fan on it, I.E. from a turbocharged model. we often did in the hot climes to keep them cooler.
One tip is that the main power jet cranks open at about 22.5". keep it a shade under that and you'll cruise at 3 to 4 litres per hour less and only 1 or 2 knots slower.
Another tip, if you have a wet sump engine always keep an eye on the magneto idler gear shaft where it bolts into the accessory housing. if there is one drop of oil seeping from it, do not fly - it will fail inside the next 25 hours.
apart from that they are bulletproof, and magic to oprerate.