Radiator Shroud Build - How To Build A Dirt Late Model Shroud

Building your own radiator shroud is relatively easy, will save you money and can greatly improve the efficiency of your cooling system. Begin by making a trip to your local craft store and pick up some poster board. Use this to create a template for the shroud. Don't worry about making a mistake, you can tape back pieces if you cut off too much.

Building your own radiator shroud is relatively easy, will save you money and can greatly

In racing, the only thing that's free is your labor. Anything you can fabricate yourself is money you've saved that can be used on something else (or just not spent at all!) to advance your racing program.

One area where you can definitely save a few bucks with minimum fabrication skills is by building your own radiator shroud to make sure all the air going through the grille also goes through the radiator instead of simply swirling around inside the engine compartment. If you are having heating problems during the hotter summer months, a radiator shroud can definitely help. Air, like water, will always choose the path of least resistance. And when there is no shroud to force it through a radiator, much of the airflow through the grille will wind up hitting the radiator and simply going around it.

We followed along as Dirt Late Model racer Chris Hargett created the patterns and fabricated a radiator shroud as he finished his new race car. The chassis is a Mastersbilt by Stuckey (a Mastersbilt chassis modified to specifications set by Stuckey Enterprises), but this method will work with practically any car. For simplicity, Hargett used the nose as the roof of the shroud, and the bottom is left open. And finally, before we get started, eagle-eyed readers will note that there is no grille cut into the nose-that was done after our shoot.

Here, you can see how the shroud routes just inside of the bumper frame for the chassis. There will be just enough room to slot it between the side of the radiator and the frame.

Here, you can see how the shroud routes just inside of the bumper frame for the chassis. T
There's nothing high-tech in this project. Driver Chris Hargett needs only a straight-edge, marker, razorblade (or scissors) and a clean spot of shop floor as he cuts his templates.

There's nothing high-tech in this project. Driver Chris Hargett needs only a straight-edge
Don't try to get it all on the first try. It may be easier to build your templates in multiple sections-we made ours in two here. It is also helpful to have a second set of hands to help hold the poster board so you can be free to mark it for more cuts.

Don't try to get it all on the first try. It may be easier to build your templates in mult

Notice how the template has been bent with two folds in the middle to take up the space where the bumper slots into the front frame horn? If you don't do this, your final product won't fit properly.

Notice how the template has been bent with two folds in the middle to take up the space wh
Here's the final template for the left side of the car, and it represents about 45 minutes worth of work. The right side will have to be done separately-trying to make a mirror image almost certainly won't work. After the project is completed, mark the templates for the left and right side and put them away someplace. If you ever need to fabricate a new shroud, you at least won't have to repeat this step.

Here's the final template for the left side of the car, and it represents about 45 minutes
Although it isn't absolutely necessary, Hargett wanted a really tight fit around the bumper tubes. To simplify the process, he first cut slots into the poster board and then filled the area back in with masking tape. Remember, it doesn't matter what your template looks like, only that it fits your car as well as possible.

Although it isn't absolutely necessary, Hargett wanted a really tight fit around the bumpe

Now the template design is ready to be transferred to the shroud material. Although you can use aluminum, the best choice is a sheet, or roll, of plastic, which is available from most racing supply stores. The plastic is actually a high-density polyethylene that's flexible and can usually stand up to a few impacts. Sheets are normally 48x96 inches and 0.100-inch thick, while rolls are 20-24 inches wide, 0.070-inch thick and about as long as you want. Which you use is up to you.

Now the template design is ready to be transferred to the shroud material. Although you ca
Here's the template after it has been traced out on the plastic with a permanent marker. Notice how Hargett has made tic marks where the bends will go to follow the frame horn.

Here's the template after it has been traced out on the plastic with a permanent marker. N
Cutting the material is easily done with tin snips or a Beverly shear. Afterwards, use a file to knock down any sharp edges. If you don't, there's no telling when a member of your crew will come up bloodied when thrashing on your car between heat races.

Cutting the material is easily done with tin snips or a Beverly shear. Afterwards, use a f

The plastic can be bent in a sheetmetal brake without cracking.
Here it is fitted back up into place. Notice how the bend in the plastic also provides a bit of shielding for the left-front shock's remote reservoir.

Here it is fitted back up into place. Notice how the bend in the plastic also provides a b
After everything is like you want it, drill a few holes in the plastic and secure it to the frame horn and bumper tubes with zip ties. This makes it easy to remove in a hurry if you have to perform any repairs at the racetrack.

After everything is like you want it, drill a few holes in the plastic and secure it to th

Here's a look from the inside. You don't have to have the shroud extend all the way to the lower lip of the nose of the car, that way if you hit a rut and the bottom of the nose gets folded in a bit, it won't deform the shroud.

Here's a look from the inside. You don't have to have the shroud extend all the way to the
The final product. Now it's easy to see how all the air coming through the grille will be forced through the radiator and maximize cooling efficiency.

The final product. Now it's easy to see how all the air coming through the grille will be

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Build Your Own Radiator Shroud

Keep Your Cool By Building This Simple-But Effective-Shroud To Help The Radiator Run As Effeciently As Possible