Since nobody mentioned it here, I guess I will. Do you have the radiator support to hood seal in place, and the lower radiator support to splash pan seal? With a mechanical clutch fan and factory shroud, you are trying to create a vacuum where the fan pulls air through the radiator, and the area behind the grill is sealed so that air is drawn through also. Without the upper and lower seal, it’s like sucking through a straw with a hole in it.
I also agree about the flat ambient air space of a flat shroud. Think of the conical shaped factory shroud as a funnel, if you dump all the liquid into a funnel, it will bottle neck up…..yes, it will still go down but not until it’s oriented itself in the cone and is drawn down by the water preceding it. Swirl the funnel around just a bit and the water goes right down the hole. Like merging in construction on the freeway, everybody eventually gets through, but if everybody waits till the last minute to merge it’s a bottle neck. A flat shroud acts as somewhat of a barrier, a conical shaped shroud does not.
You’re seeking a continuous flow of air through the shroud, and sealing the area and drawing the air through with the least amount of resistance as possible is paramount. The clutch portion of the fan is what regulates the flow according to temp and air flow, at speed it will freewheel somewhat because there is ample airflow, in traffic it needs maximum draw.
And for the record, 200 is not hot, most engines run at that temp intentionally. An iron big block Chrysler engine for instance, calls for a 190 thermostat. Don’t get too hung up on temps in that range.
I also agree about the flat ambient air space of a flat shroud. Think of the conical shaped factory shroud as a funnel, if you dump all the liquid into a funnel, it will bottle neck up…..yes, it will still go down but not until it’s oriented itself in the cone and is drawn down by the water preceding it. Swirl the funnel around just a bit and the water goes right down the hole. Like merging in construction on the freeway, everybody eventually gets through, but if everybody waits till the last minute to merge it’s a bottle neck. A flat shroud acts as somewhat of a barrier, a conical shaped shroud does not.
You’re seeking a continuous flow of air through the shroud, and sealing the area and drawing the air through with the least amount of resistance as possible is paramount. The clutch portion of the fan is what regulates the flow according to temp and air flow, at speed it will freewheel somewhat because there is ample airflow, in traffic it needs maximum draw.
And for the record, 200 is not hot, most engines run at that temp intentionally. An iron big block Chrysler engine for instance, calls for a 190 thermostat. Don’t get too hung up on temps in that range.
