My experience with electric fans is that they are great for slow traffic but not very good at high speed pulling a hill. Installing a curtain below the rad and the cowl box is a help. It is a lot of little not just one item. In My experience with a +4. Engine timing is paramount.
On My +4 I use a Morgan Spares Fan, but I trimmed the blades myself to make them more aggressive. I also have a shroud (Designed by Bob Nogera (Texas). If I could figure out how to send pictures I would send one of this contraption. It works!
