When it comes to cooling a Tri-Five Chevy, the options are all over the map. Stock radiators typically need repairs, and they’re usually not efficient enough to cool most high-performance engines. For the past 20 years or so, it has been popular to swap the original copper and brass radiator for an aluminum unit. While aluminum radiators are physically lighter and do a good job of cooling, there is no replacement for a tried-and-true copper and brass radiator when it comes to durability and longevity.
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Many years ago, Vernon Walker and the folks at Walker Radiator Works in Memphis, Tennessee, developed trick internal components that allowed brass and copper radiators to outperform most radiators on the market. Walker was known mostly for street rod radiators but later got into the ’50s and ’60s applications, including the Tri-Five Chevy. Shorter fins allow for more tubes to increase capacity, while louvers in each fin create air direction changes for much better cooling capability.
Every Johnson’s Radiator Works radiator starts with core assembly. A giant roll of brass stock is fed into a machine that bends it into a 0.125- by 0.500-inch tube. The machine then closes the tube with a Pittsburgh seam for strength.
When Walker closed its doors, hot rod builder Alan Johnson bought the entire operation, including all the machinery, patterns, and notes that dated back for decades of design and production. The name wasn’t part of the purchase, so he renamed it Johnson’s Radiator Works and moved the machinery to a facility near his hot rod shop in Gadsden, Alabama.
The same machine feeds the tubes into a solder coating area, and finally into a cutting area. The tubes are cut to length, based on the dimensions of the core, so each radiator has its own tube length and quantity.
Johnson and his staff take great pride in building radiators for a 70-year span of vehicles, from Model Ts to ’90s Chevy pickups and everything in between. We recently had the chance to watch the team build a Tri-Five radiator and it was eye-opening to see exactly how much work goes into each radiator. It is truly a handcrafted piece. Johnson’s Radiator Works builds every component, aside from the drain petcock, in-house. While there has been a learning curve on the intricacies of manufacturing radiators for so many different applications, each member of the staff knows every step of the process.
Fin production also requires a special machine that takes flat copper stock and gives it the accordion shape. During this process, each fin is stamped with louvers to create thousands of air direction changes to increase efficiency.
Follow along as we show you how Johnson’s Radiator Works builds a highly efficient radiator that will bolt directly into a Tri-Five Chevy and keep it cool with traditional copper and brass construction.
Each core is hand-assembled using the designated number of tubes and fins. This fixture allows for easy stacking of the materials. The shorter fin height (0.250-inch) allows for more rows of tubes for additional cooling capability.When the core is assembled to the proper specifications, it is dipped in a heat-activated flux and then lightly blown out with compressed air.Four radiator cores are laid onto a large rack, which slides into the curing oven. This oven melts the solder, which fuses the tubes and fins together.The next step in the process is the header panel, which is built from flat brass stock. The oval-shaped flanges are punched with a special die to create a tight fit around each tube.Glenn Jackson carefully installs the header panel on the core. The tight fit makes this a tedious process, but it’s part of what makes the radiator strong and reliable.After the two header panels are fitted to the core, the assembly is dipped in flux and then dipped in solder. Jackson measures the depth to ensure that the solder only coats the header and tubes.Jackson uses compressed air to blow the liquid solder out of the tubes before it dries, and then rinses the core with water to prepare it for final assembly.Brittany Winningham steps in to help Jackson feed brass stock into the shear. These pieces are used to fabricate the tanks. For a Tri-Five Chevy radiator, the upper tank is stamped and the lower is cut and formed from one piece of brass.The bottom tank blank gets bead-rolled for strength and then goes through a series of punches to prepare it for final forming. The oval hole is punched for the radiator hose outlet and a small hole is punched for the drain petcock.A metal brake is used to fold the edges of the brass for a strong, finished edge that will fit tightly in the header panel.After folding the edges, Jackson uses another metal brake to bend the tank into the desired shape. These bends are based on notes specified in Johnson’s extensive library of dimensions for each radiator build.Jacob Gomez uses the spot welder to fasten the corners of the tank. The seams will be brazed on the inside and then filled with solder on the outside during the final assembly process.The Johnson’s Radiator Works Tri-Five radiator features a stamped upper tank, so it goes through a slightly different process than the lower tank. The stamped tank moves to the next station where it gets holes punched.The filler neck hole is punched with a special die that creates a tight fit with the neck, which is made in-house.Finally, the upper tank is stamped with the Johnson’s logo and then stamped with a serial number.Alan Johnson brazes the inner tank seams, and then brazes the lower radiator hose outlet for a strong bond.The completed core is placed in a rotating and pivoting fixture to give Johnson full access for soldering the tanks.Johnson fits the lower tank into the header panel and then hammers the flanges down for a tight fit. Then, it’s time to fire up the torch and solder the joints.The lower tank has a drain petcock, so Johnson attaches the bung with solder.Johnson fits the stamped upper tank to the header panel and fine-tunes the fitment with a few soft blows of the hammer.Johnson is a perfectionist, so his solder work is always sanitary and strong. This long run of solder across the front and rear of the tanks requires patience but Johnson enjoys the challenge.The upper radiator hose outlet fits tightly in the punched hole and then Johnson secures it with solder for a long-lasting bond.Twelve-gauge steel is used to fabricate the mounting brackets, which allows you to easily bolt this radiator to any Tri-Five. Johnson attaches the steel mounting brackets to the radiator with solder.Every radiator build is pressure-tested before it is painted and boxed for shipping. Johnson’s radiators are designed to operate with a 15- to 18-pound cap, so he applies 20-plus pounds during testing.After pressure testing, the radiator is flushed with water and allowed to dry. It is then placed on an assembly line that leads to the painting station.The final product is an American-made copper and brass radiator that is guaranteed to bolt directly into your Tri-Five Chevy and keep it cool for many years to come.
