On the tow back from Auckland the other week we had some overheating issues in the exhaust trunking. I believe it was lack of ventilation.
So drilled and installed 4 copper vents under the mizen mast. I also vented the trunking in the loo up thru a large cowl vent on the cabin roof.
In addition I have been instructed to ensure the engine air inlet goes down to the bilges, so have installed a plywood duct in the engine room.
Time for testing....