To increase airflow at slower speeds a fan is used to draw air through the radiator. A multi-bladed fan attached to the water pump hub, driven by the engine, offers the most efficient means of doing this. A shroud covering the entire core area and funneling the airflow out the rear opening makes this even more efficient.
In many applications the engine sits too low in the frame and has limited clearance at the front of the engine. This makes the traditional mechanical fan/shroud combo impractical. Electric powered fans offer the best alternative. They are thin and can be located anywhere on the face of the core, though near the top is recommended because in top-to-bottom flow radiators hot coolant is returning there from the engine.
A shroud makes these much more effective but most of the shrouds have moved the fan back from the core too far. Fan manufacturers have continued to reduce the thickness of the fans and now there is a shroud from Cool Craft that when combined with the fan only measures 2-5/8-inches thick. It’s made up of a 1/2-inch thick formed-aluminum shroud and one or multiple electric thin-line fans. Tabs on the side of the shroud attach to the flanges on the radiator side plates with sheet metal screws.
My ’32 Ford hi-boy roadster proved to be the perfect application for this unit. The Buick Nailhead sits low in the frame and clearance between the thick radiator core and the water pump make the use of the stock fan impractical. I only have 2-5/8-inches between the core and the shaft on the pump. The 1/2-inch thick shroud clears easily but the 16-inch diameter fan had to be moved to the top of the shroud for clearance. The shroud can be ordered with the hole at any location or supplied without a hole and you can cut it out once you determine where to locate the fan. However, it’s better to supply the simple measurements they need so they can cut the hole and attach the fan mounts.
The photos and captions show the simple installation and the following information from Cool Craft illustrates what specifications and measurements were needed to complete this installation.