The car still seems to be overheating after having it set up and running fine on the rolling road at 190bhp but even driving it normally down the motorway the temperature is going right up near the red until you turn the heaters on full

The car has a new re-cored rad, with pro alloy front mount intercooler.

Couple of things i want to check

What does that valve do in the picture for the coolant system? The one with the white plug



Also does it matter which way round the hoses go onto the heater matrix? The bottom one going to the Y piece



If these are correct what could be causing it to run so hot?