So where do you find shrouds for older cars? That’s simple too: The restoration aftermarket is loaded with quality reproduction shrouds for all sorts of applications. The bottom line is simple: If you don't run a proper shroud, you're only asking for overheating grief. If the shroud is not present, it creates a considerable amount of 'dead' space behind the radiator that in turn destroys the effectiveness of the fan assembly. This isolates the pocket of air behind the radiator, allowing the fan to efficiently draw the required air through the radiator. It butts up tightly to the face of the radiator, effectively sealing the cavity. How does the shroud work? Basically, the shroud surrounds or partially surrounds the fan. If you don’t have a shroud or if it fits poorly, get the right one (that's a big hint if you end up sitting behind Old Faithful on a regular basis). Keep in mind that shrouds are often manufactured from plastic and as result, the condition typically degrades dramatically over the years. Unfortunately, they are often missing on any number of older cars. Increasing the airflow through the radiator improves the cooling and as a result, a shroud is almost mandatory on high performance applications. The idea is of course to provide a constant supply of air through the radiator so that the coolant is reduced in temperature. But when it comes to cooling you absolutely must first figure out a way to bring the air to the radiator (cooler). This is to accommodate normal engine and radiator movement, and also the flex that occurs in the fan blades at higher engine rpm.Ĭhecking these measurements when running a belt-driven fan and a fan shroud will solve overheating problems and fan contact problems caused by improperly placed fans and shrouds.No one likes a car that overheats. There should be at least 1 inch of clearance between the two. The last measurement you should check is the distance from the face of the fan to the radiator. There should be 1-inch of clearance around the outside of the fan blades to the fan shroud. This can damage the fan shroud and the fan. If there is not enough clearance, you run the risk of the fan contacting the shroud with natural engine movement and body flex that affects the radiator and fan shroud mounting. If there is too much space here, the fan won’t be as efficient as it could be in pulling air through the radiator. The other very important fan to fan shroud measurement is the distance around the circumference of the fan and the circular opening of the shroud. This causes dissimilar resistance along the length of the fan blades, which stresses them. It’s also important that the fan blades do not extend past the top, bottom or sides of radiator surface. Make sure you use Flex-a-lite spacers using any other brand with a Flex-a-lite belt-driven fan will void the warranty. You can use 1 or more spacers – up to 3 inches in total.

We manufacture a variety of fan spacers to move the fan forward and rearward, letting you achieve the optimal position. If the blades are not far enough inside the shroud, the fan will pull air from around the shroud rather than through it. Instead it will create turbulence inside the shroud, spinning the air, but not efficiently pulling it through. If the fan is too far inside of the shroud, it won’t pull as much air through the shroud as it could. Looking from the side of the engine, the fan blades should be half in and half out of the shroud.

If you have a fan shroud, the position of the fan blades in the shroud is very important to maximize airflow. Most people that have cooling problems with a belt-driven fan at idle and slow speeds don’t have a shroud – their fan is drawing very little airflow through the radiator, and most of their cooling comes from ram air being driven through the radiator at speeds above 40 mph. Without a shroud, air will take the path of least resistance, pulling air from over and under the radiator instead of through it. If you rely on a belt-driven fan for engine cooling, a fan shroud is a must to pull the air through the radiator. The first thing we want to make sure is that you actually have a fan shroud.

It’s critical that the fan be positioned properly within the fan shroud and that there is just enough clearance around the fan blades. If you’re running a belt-driven fan, there are a few things you need to do in order to maximize the engine cooling that the fan can provide.

Radiator fan shroud