Originally Posted by dilligaf
1940 Willy's. The further I drive the car the hotter it gets. New aluminum radiator. New full shroud. New spal slim line 16" fan. Car runs good but just gets hot. It has a small block chevy engine. Carburator and a mild cam. There is a sheet of aluminum blocking air flow from passing out from under the radiator Please send ideas. Thanks.
First place I'd look is at pulley ratios. The further one gets from what the factory would have used the more problems you begin to get. These old car instllations are usually pretty much on edge as there just isn't enough space for a modern radiator. So if you slow the pump while hunting more power you usually end up with a lack of sufficient flow to where the engine gradually overheats.
If it overheats without a thermostat this condition will probably not change with one.
Modern air flow through the radiator is less concerned with ducting air into the radiator than with creating a low pressure area under the engine compartment to help vent air through the radiator and out of the engine room. This is why most new vehicles have a chin spoiler.
The addition of an oil cooler can be of large benefit to reducing the coolant temp. An effective oil cooler can take 10-20 degrees off the coolant temp.