William2 wrote:I assume that the fan on the front of the rad should be drawing in air from the nose of the car and pushing it towards the engine??
I'm not convinced that this is the case. Especially with rad mounted fans (as opposed to the un-shrouded OEM fan that was closer to the nose/grill).
Fans will pull air from the path of least resistance. Which is typically the shortest distance. The rad mounted fans are closer to the engine bay than the nose/grill. So when sitting still, I'm thinking a decent percentage of air that's coming into a rad mounted fan is coming from the engine bay.
This is where the design and size of the Elan engine bay is the issue and why the wheel well vents help.
Blocking the open area surrounding the rad seems like it might help to increase the percentage of "fresh" air from the nose/grill that the fan sees.
For what it's worth, on our race cars we'd make tin work to shroud the radiator all the way to the nose/grill preventing any possibility of the radiator seeing air from the engine bay. Far easier in a tube frame race car than in a very complex shaped OEM car. And the point of doing this wasn't the thermal runaway that we're considering here. It was to make sure that all air that got under the car was "used" for cooling and thus generated the least amount of lift from under hood pressure.