21st Century Cooling - Radiator R&D, Part 1: Design to Delivery

21st Century Cooling - Radiator R&D, Part 1: Design to Delivery

This 2004-2008 Dodge Ram 5.7L Hemi Radiator is now on sale! Check it out here!

Chrysler's Hemi engine has been an icon of innovation for almost 75 years. Since its first test runs in the P-47 Thunderbolt fighter plane and stint powering the M47 Patton Tank, the Hemi has been evolving to become one of the most widely used engine designs. The Hemi is the chosen design for engines in top fuel dragsters, just about every insanely powerful MOPAR car, and our subject, the 2004-2008 Dodge Ram 1500 5.7L.

While the 5.7L Hemi under the hood of the 3rd Gen Ram 1500 is the result of decades of innovation and evolution, some of the components supporting it are still stuck in the past. The plastic end-tank radiator, for example, hasn't quite caught up to the times. The stock 5.7L rad was enough for stock trucks from 2004 to 2008, but ten years of use has taken its toll. Not to mention, the Hemi platform was designed to make power, and more power means more heat.

For the past few months, Mishimoto has been working to bring the 5.7L Hemi radiator into the 21st Century.


The first step in modernizing the 5.7L radiator would be to examine the stock radiator. We didn't want to do away with every aspect of the stock rad; after all, it does fit the truck. So, we popped the hood of our volunteer Ram and studied what we needed to keep and what we could make better. We were surprised to see that the radiator in the 1500 was situated off to the passenger side and angled away from the radiator support, instead of in the middle of the grille like on the HD variants. To make our radiator fit like stock, we would have to replicate this unusual mounting structure. For that, we turned to our 3D laser scanner.


Using data from the 3D scanner and measurements taken while the radiator was installed on the truck, our engineer 3D printed the radiator end tanks and mounts for our prototype rad. While the end tanks and mounts would remain mostly unchanged, the radiator's core would require more work. Like all heat exchangers, the core of the 5.7L radiator bears the biggest responsibility in determining how well the radiator performs. Our radiator packs a core between the end tanks that is over 75% thicker than the stock core, with more tubes and fins to make the most of the available airflow. To make sure the significantly larger core would fit, we needed to join our 3D printed end tanks to a prototype core. Instead of constructing a full core with tubes and fins, we turned to our fabricator to build an aluminum tube stand-in that would tell us everything we needed to know.


Once the welds on our prototype core had cooled, we constructed our prototype radiator and test fit it in our volunteer truck. Our engineer quickly drained the coolant from the stock radiator and removed it. Our prototype was installed a few short minutes later. Despite the strange mounting location and angle, our larger prototype fit like a glove.


A successful prototype test fit meant that we could be confident that our more evolved 5.7L Ram 1500 radiator would fit like stock and perform even better. But to be 100% sure, we needed to see the final product. We needed a production sample. So, we set to work creating an all-aluminum radiator for one last inspection, and a few weeks later, that production sample was complete.


We checked the product sample over to make sure it met all our specs and test fit it on our volunteer truck one last time. It's obvious that our radiator looks better than the stock 5.7L 1500 rad, but with its 78% thicker core and 29% greater coolant capacity, it's also safe to say that it will perform better too. While we finish up production, this radiator will be going on discounted pre-sale. Finally, the 5.7L Hemi in your 2004-2008 Dodge Ram 1500 can have a radiator as evolved as it is.

Thanks for reading!