By Freddie Heaney:
A call from a Muscle car owner arrived out of the blue. He told us there’s an aluminum repair specialist in Doraville, whose work deserves recognition, and if you want to learn about such a service, you won’t find another closer.
In Muscle car circles, Doraville, a northern suburb of Atlanta, usually suggests one name: Lamar Walden Automotive. And so it proved to be.
Walden’s shop has long been prized for its machining capabilities as well as its engine and car dynamometer resources. But the firm is, perhaps, better known for pioneering performance versions of GM 409 engines of the 1960s and a front-runner in all GM performance engines, including today’s LS variants. The caller was right; their aluminum repairs department is less familiar.
What were the motivations? Normally, one doesn’t think of sending car parts to a machine shop for concours d’Elegance restoration, but that’s exactly the kind of work they undertake at this shop.
“My Dad, Lamar, started it.” says Rob, “He came up with the process for the many restoration cars he built. And it’s not just repairing and restoring cracked or broken intake manifolds, for there’s a steady flow of transmission casings, alternator housings, valve covers, engine blocks, and bell housings–broken and blemished parts arrive from across the country. Basically, the service includes anything aluminum.”
Aluminum intakes are often warped, particularly after being changed from one engine to another. Other common problems in aluminum castings arise through over-tightened bolts that crack the bosses and damage the treaded holes
The repair process begins by dismantling the component and then cleaning to remove all the grease, the grime, and the oxidation. Seized and broken plugs and studs are removed and cracks ground out and TIG welded.
Carbide cutting burrs and air grinders are used to dress the weld surfaces and openings and holes are reformed by using CNC equipment to re-drill them.
Broken lugs that have been lost are re-created and TIG welded in place. Welds are ground, contoured, and blended. All mating surfaces are presented to the milling machine for cutting and truing. Some intake manifolds require a thin skim to restore flatness to the mounting flanges while others require 0.030in cut and thicker gaskets
Walden’s restorative finishing process is of their own creation—a proprietary process they call re-skinning. The objective of the re-skinning process is to close the pores, inhibit oxidation, and bring the surface to a uniform luster reminiscent of the OEM finish rather than the less than appealing white lifelessness of sandblasting.
It’s important to note that glass beads make short work of grime and other crusty surface affronts; they clean steel and aluminum parts equally well without damaging the surface. But blasting metal, particularly aluminum, with only glass beads opens the pores of the metal’s surfaces and, hence, is not conducive to a long-lasting clean attractive finish. Gasoline, oil, and grime tend to stain aluminum. So, if you want the endeavor to be successful, it is better that it wipes-up well. Fully functional and aesthetically pleasing, this repair and refurbishment program might be to your liking.
Lamar Walden Automotive