How 3D Printing Technology Is Keeping Old Cars Running

Collector Jay Leno turned to additive manufacturing to repair a 1913 Packard, and the same tech could work on your next project.

Additive manufacturing, or "3D printing," is commonly used for prototyping, as the machines can create parts without the expensive tooling process or the need for skilled machining. Automakers use it for design, and occasionally even for production parts, and companies like Czinger are using it to create major structural pieces for lightweight sports cars. We've seen some hot rod shops make use of the tech too, but it wasn't until we saw Jay Leno speak at a networking event held by the Aria Group—a manufacturing company that partners with 3D printing firm Stratasys—that we learned how useful additive manufacturing can be to collectors and restoration shops.

Leno and his chief engineer, Jim Hall, shared examples of how they’ve used 3D printing to keep Leno's extensive collection of unusual automobiles running. Later, we had a chance to visit the garage and see some of the parts, as well as Leno's Stratasys Fortus 450mc 3D printer, for ourselves.

There are different methods for 3D printing depending on the material and the intended use. Some, like what Czinger uses, print via fine applications of powder, to create a production-ready piece of metal. Leno's machine is a fused deposition modeling (FDM) machine that uses reels of plastics to make prototype parts that can then be cast, sample parts to test fitment, or one-off components.

One of the first examples we were shown was work Hall did on a 1913 Packard. The big straight-six hydrolocked a cylinder—the engine is an L-head design with the cylinders cast in pairs—and it blew the whole cylinder apart. Hall first attempted the usual old-car avenues of repair. He sought out new-old-stock and spare parts from restoration houses and junkyards, searching high and low to find a period-appropriate replacement. It may not surprise you to learn there aren’t many 1913 anythings at the local Pick-n-Pull, so Leno and Hall had to get creative.

They used a laser scanner to capture the broken cylinder and the dimensions of the undamaged ones. With that data in a CAD modeling program, Hall was able to re-create the cylinder pair in plastic that could be sent to the foundry and used to make a new casting. Not only was this a far better method than trying to cast from the broken pieces, it also allowed Hall to test fit how the cylinder bank might fit if it were cast thicker than the original.

"I don't know how they did it at Packard," he said. "The foundry couldn't reproduce the piece that thin, but we were able to print it with additional material on the exterior and test fit it before sending it off to be cast."

"We had four of them made," Leno said. Better still, the modeling program data is still available, so if other Packard owners end up in the same situation, they can use the model to make their own engine blocks.

That's not the only prewar car in the comedian's stable that has enjoyed the fruits of additive labor. There's also a 1907 White steam-powered car. Despite decent popularity in their day, many Whites were scavenged for scrap aluminum during World War I, and as a result, fewer than 100 still exist today out of the more than 10,000 that were built. Whenever his White needs a repair, Leno scans the aluminum parts and prints a casting pattern in ABS plastic.

About 50 years after that steam car first whooshed down the road with a puff of water vapor, the Pontiac Firebird Sprint rolled off the production line. Envisaged as a cheaper American rival to poised European sports cars, the Sprint featured a sophisticated overhead-cam inline-six that sounded slick, revved high, and made a healthy 215 horsepower. Unsurprisingly, convincing muscle-car buyers to go for an expensive, high-tech six over a husky V-8 was a challenge, so the Sprint was a rare bird when new and virtually unobtainable today. So of course Jay Leno owns one— a 1968—and of course he needs parts to keep it in excellent condition.

Finding NOS or reproduction parts for lots of muscle cars is simple. Shared part numbers and extensive documentation mean there are factory items at auto dismantlers and factory-quality pieces online and everywhere else. But when you have a car like the Firebird Sprint that was rare when new and mostly overlooked by collectors in the intervening years, body parts and trim pieces are rare (to say nothing of whole parts cars). While it's not as vital to operation as an engine block or aluminum pipe fitting, the Firebird's engine cover came from the printer, polished and finished to cosmetic perfection.

"We have been able to fix things that were unfixable because in my business, when Ifirst got started dealing with cars, you'd go to a junkyard and find stuff," Leno said. "Those parts don't exist anymore . . . And now you have the technology to make the parts that you want. It's just unbelievable."

Additive manufacturing isn't limited to obscure and/or centuries-old automobilia, either. The Aria Group uses Stratasys printers to build concept cars, prototypes, and low-volume specialty parts. Prominently displayed in Aria's production shop was an early mule of the Nilu hypercar, as well as an Everatti-converted Porsche 911 EV and a Scarbo Designs SVRover trophy truck. Although Aria didn't reveal which of its 3D–printed parts found their way into those vehicles—trade secrets and all that—company representatives did say that they were structural and vital to vehicle function, not merely cosmetic.

Even giants like Toyota take advantage of additive manufacturing, using Stratasys printers to make parts for the GR86 Cup Car. As we learned on an unrelated trip to the manufacturer's GR Garage in Charlotte, North Carolina, each GR86 Cup Car starts life as a factory-fresh sportster before being stripped down and rebuilt using sophisticated, lightweight materials. As for Stratasys, that means interior door panels, hood vents, and aero aids.

Different materials can be used in the same printer, so for example, when Leno wanted an airbox for a Roush V-8 in his '66 Galaxie, that had to be made from a heat resistant material, the same stuff that can be used to make molds or tooling that will go in an autoclave under high heat or pressure. Carb spacers on a Rolls-Royce needed to be fuel stable, again a specific material. The spools of plastic wire that Leno's machine use come in cartridges that can be swapped out and reused—the cartridge keeps track of how much is left inside—so Hall can print some dummy turn signal mounts to test-fit his blueprints on a Detroit Electric car before sending them off to a machinist and then swap in a different material to make carb spaces, or even use a water-soluble plastic for printing out tooling that could be wrapped in composite or silicone and then washed out.

We're not all so blessed as to have a chief engineer and a 3D printer in our garages, but the next time you're stuck on a resto project, it might be worth looking up a shop in your area that does. Stratasys even runs a program that offers large and small-scale printing on demand. Perhaps you'll get lucky and find out that Leno has already made the blueprint for the part you need.

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