Tech
Images by Roadster Shop
n past articles we looked at some of the preliminary work being done by Roadster Shop on this outstanding 1965 Corvette. This time, we’ll take a close look at the intricate radiator fan shroud, the all-stainless exhaust system, and the aluminum pan that seals off the bottom of the body at the rear.
This car uses a temperature-controlled SPAL electric fan for the radiator, along with the belt-driven fan on the front of the engine. The electric fan helps manage coolant temperature, even when the car is idling for long periods and after the engine is shut off. There is precious little room under the hood of this car, so great care was taken to position each component with adequate clearance, ensuring nothing looks crowded or out of place.
The first step was mounting the electric fan on the back side of the radiator, accomplished by making a shallow perimeter frame from sheet aluminum. Next, the circular portion of the shroud was formed by putting a 1-inch flange on a strip of aluminum and shrinking the flange to create the round shape. Once the part was accurately formed and sized, the seam was welded and metal-finished.
Marrying the round shroud to the rectangular frame required some creative thinking. Three sides of the circular piece were scalloped away, and the gaps were filled with flat aluminum inserts, each fitted like a puzzle piece. The bottom section was the real challenge—it needed to snake around several obstacles yet still look as though it belonged there. Through patient test-fitting and subtle shaping, the Roadster Shop team precisely developed the required geometry.
Triangular tabs were then welded to the corners of the shroud, allowing it to be mounted to the fan frame. Finally, an elegant mount was made to connect the top of the radiator to the core support.
The sinuous exhaust system was built from 3-inch stainless tubing. All of the bends were painstakingly fitted to the straight sections so there are no kinks or discontinuities, keeping backpressure to a minimum. TIG welding was used throughout, and each tube was purged with argon gas to keep the inside of the weld clean and smooth.
Stainless moves significantly as it heats, so several expansion joints were incorporated into the system, allowing each section to move as it “breathes.” Sturdy mounts were positioned to hold each component in place, allowing the entire system to come apart easily if service is ever required.
Electrically operated cutouts are fitted on both sides of the exhaust system, allowing the exhaust gases to bypass the mufflers at the touch of a button and be routed through the side pipes.
The mufflers are concealed behind the rear suspension, and the original openings in the body for the exhaust tips were filled in for a cleaner look. Short, nearly invisible tips now direct the exhaust downward; you won’t see them unless you’re willing to crouch down and look carefully.
The area above the mufflers was carefully enclosed with a special pan made from aluminum sheet, which finishes off the underside of the body in an elegant manner.
In a future issue, we’ll explore how the final details came together on this beautifully constructed car, and how each finishing touch adds another chapter to its transformation.
