Placement of the louvers and the quantity is something that needs to be planned. My buddy added them to the top of the hood of his 40 Tudor to relieve excessive engine heat which was effecting his engine performance.
After recognizing they were doing a great job of moving the hot air, he found that he couldn't use the cowl vent without flooding the inside of the car with hot air. In addition he carries a shower curtain to cover his engine (after it cools down) to keep the rain from soaking everything.
He had to add a/c to compensate for the lack of cowl vent air...so it was discovered that his radiator was partially clogged up when they added the condensor. He sheepishly jokes that his 60 louvers cost him $30.00 each.
Just something to consider.......
Dave
