In my build I ducted all the air out of the top of the hood. I was unsure if the screen was large enough. I had an additional vent to allow more air through if needed.
Since I have been able to drive the car I have been able to test it more. 30 min of driving is seeing temps in the 220-230 range. It is a basses to start from. This weekend I opened the hood vent and drove about 30 min and the temps never got over 180!
So I know I need more air. I'll leave the vent open for now but I will be building a new vent with louvers in it to increase the flow.
Incidentally, I have a side mounted oil cooler set up with fan. When it got warm the oil temps would follow. When I would turn on the oil fan it was very effective in dropping oil temps even when the water was too hot.
I have 2 temps sensors in the side mounted oil cooler; one before and one after. It was so effective there was quite a bump in oil temp before and after when the fan is on.
These are good experiments. At least now I know!
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