Your on the right track, but, I do recommend that a "dam" on the FRONT of the rad is what really helps the flow through the rad. I was good that you open up that shroud, as you would not have had enough flow through the rad. At spead the fan is really not an issue, whereas the air stalling in front of the rad, as what lessens the cooling. Making sure the rad is sealed to the radiator support, so that the air has to go THROUGH the rad, not around or down the bottom, is what really helps the whole cooling issue. The plates fro your mounting frame shoud stand off from the rad a bit, but, the shroud around the rad should be tight to it. A small 1/4 to 1/2 " gap can make as much as 200 CFM difference in air flow. ( based on chart that came with the fans the Byron and I used.)
Check out the thread I did in the spring on my radiators "dam" that I finally did for mine. TECHNICAL/FAN SHROUD PROJECT.
Having watched what Specialty Engineering has done on all the cars he builds, he spends as much time on the front side of the rad, as he does on what is happening to the back side, in regards to air flow.
One of the reasons of the long term success of my motor, and any performance motor for that fact, is of keeping things cool. Keeping the thermal load under control cannot be understated, and as the compression and power goes up, that becomes even more of a task. While getting a good sized radiator in there is paramount, getting the air to flow through the rad, as efficiently as possible, is a big bonus too.
The air can and will stall to a certain extent, and take the path of least resistance sometimes, going through every other opening it can find. With that in mind, a common practice is to seal, and/or build walls and dams, to make the air go just through the rad. This is a very simple project I have wanted to do for some time. So, with a sheet of construction paper in hand, I made the templates, four pieces in all. Then, with everything laid out, and looking ok, I transfered the paper paterns to 3/32" aluminum sheet. I rough cut those on a shear, then, bent them as needed. I then laid out the holes on the aluminum, then transfered that to the rad support, and drilled that. Bolting everything together loosely, let me check that all dimensions stayed true to the originals. I put a small bend in the bottom piece, as a bit of an "aero dynamic lip", and, I though it just looked a bit better than a straight piece.
I used stainless screws and Nylocs for the hardware. I even siliconed the openings right beside the rad tanks and the start of the fins, so no wasted air escapes going through the cooling fins and cores.
Total cost of project was about 25.00, which was the paint, the stainless, and a small piece of aluminum from the salvage guys.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer