Radiator Fan shroud and Air Dam There are several different ways to keep these motors cool but this is one way that we have found to work. By putting a 4 to 5-inch shroud on the front of the radiator, any air that is in front of the radiator will have to go through the radiator. It is held in place on the top by drilling a half inch hole and placing it under the rubber grommet of the radiator hold down. The bottom is held in place with two zip ties through the corners of the shroud and around the pegs on the bottom of the radiator. The air dam on the front will kick up any air that is going under the car forcing more air into the radiator. The pictures below show an example of how you could mount everything. Instead of drilling into the frame to attach the air dam, you should use hose clamps or some other mean of attachment.