My former 4/4 4-seater (1991) suffered from overheating when climbing mountain passes in summer; switching the heater on maximum (as Herman mentioned) does affect the coolant temperature substantially; also can the change from ordinary tap water to proper coolant liquid bring some relief.
By the way, the CVH-engined Morgans are known for activating the coolant fan for a few minutes after switching off the engine.
D'herde Bart
